This document provides an overview of RNA structure and function. It discusses 7 main types of RNA: ribosomal RNA, transfer RNA, small nuclear RNA, guide RNA, small regulatory RNA, antisense RNA, and housekeeping RNA. Ribosomal RNA makes up 60% of ribosomes and catalyzes peptide bond formation during protein synthesis. Transfer RNA transports amino acids to the ribosome and ensures the correct amino acid is added through complementary base pairing between its anticodon and mRNA codons. Small nuclear RNAs are involved in splicing pre-mRNA. The document also discusses RNA secondary and tertiary structure, and how tRNA structure enables its role in protein synthesis.
The document summarizes key details about Tobacco Mosaic Virus (TMV), including its history, structure, and replication process. It notes that TMV was the first virus to be purified and shown to consist of protein and nucleic acid. Studies in the 1930s-1940s revealed that TMV has a rod-shaped structure consisting of a protein coat containing a single strand of RNA. The RNA acts as a template for the virus to replicate by synthesizing more copies of itself within the host plant cell. TMV remains an important model system for understanding viral structure and replication.
DNA replication is the process by which DNA is doubled. It occurs in three stages: initiation, elongation, and termination. In initiation, initiator proteins recruit replication proteins to origins of replication, unwinding the DNA helix. DNA primase synthesizes RNA primers, and DNA polymerase extends these primers to replicate the DNA. During elongation, leading strand replication occurs continuously while lagging strand replication occurs in fragments called Okazaki fragments. Termination occurs when replication forks meet or reach chromosome ends.
Viruses consist of genetic material surrounded by a protein coat. They can have DNA or RNA as their genetic material and come in various shapes. The document discusses the structure and classification of viruses. It describes their components, sizes, morphologies like helical and icosahedral shapes. It provides examples of plant, animal, and bacterial viruses. It specifically examines the structure and replication of Cauliflower Mosaic Virus, a plant virus with circular double-stranded DNA genome.
Satellite viruses are sub-viral agents that depend on a helper virus for replication. The first reported satellite virus was Tobacco necrosis satellite virus. Satellite viruses contain nucleic acids enclosed in a protein coat and lack genes for replication. Satellite genomes can be single-stranded RNA, DNA, or circular RNA.
Satellite RNAs are small, linear or circular RNA strands found in certain multicomponent virus particles. They do not encode their own coat protein and depend on a helper virus for replication and encapsidation.
Viroids were discovered in 1971 and are small, circular, naked RNA molecules that replicate independently using host polymerases. Well-studied viroids include potato spindle tuber viroid and av
1. DNA replication begins with the unwinding of the DNA double helix by the helicase enzyme. This exposes the two strands of DNA to serve as templates for DNA synthesis.
2. RNA primers are synthesized by the primase enzyme and DNA polymerase adds complementary nucleotides to the 3' end of each primer, elongating it into DNA.
3. The leading strand is synthesized continuously in the 5' to 3' direction while the lagging strand is synthesized in fragments called Okazaki fragments which are later joined by DNA ligase.
4. Several enzymes are involved including DNA polymerase, ligase, helicase, topoisomerase and others to accurately and efficiently copy DNA. DNA replication ensures faithful transmission of
Transcription is the process by which RNA is synthesized from a DNA template by RNA polymerase. It involves initiation at a promoter region, elongation as nucleotides are added to the growing RNA strand, and termination. While similar to DNA replication, transcription only uses one DNA strand as a template and does not require primers.
INTRODUCTION:
The first plant virus shown to have a DNA genome and the first shown to replicate by reverse transcription.
Worldwide but only causes significantly losses locally.
It is transmitted by aphids .
Type member of the Caulimovirus genus, contains 11 species and 6 possible members.
significantly impact on plant virology and plant molecular biology.
The virus is an important source of gene regulatory elements, used exclusively in the genetic manipulation of plants.
STRUCTURE:Icosachedral with a diameter of 52Â nm built from 420 capsid protein subunits.
It contains a circular double-stranded DNA molecule of about 8.0 kB .
Dna is interrupted by sitespecific discontinuties resulting from its replication by reverse transcription.
After entering the host, the single stranded nicks in the viral DNA are repaired, forming a supercoiled molecule that binds to histones.
DNA is transcriped into a full length .
Replication
Risk Factors:The Cauliflower mosaic virus promoter (CaMV 35S) is used in most transgenic crops to activate foreign genes which have been artificially inserted into the host plant. It is inserted into transgenic plants in a form which is different from that found when it is present in its natural Brassica plant hosts. This enables it to operate in a wide range of host-organism environments which would otherwise not be possible.
The document summarizes key details about Tobacco Mosaic Virus (TMV), including its history, structure, and replication process. It notes that TMV was the first virus to be purified and shown to consist of protein and nucleic acid. Studies in the 1930s-1940s revealed that TMV has a rod-shaped structure consisting of a protein coat containing a single strand of RNA. The RNA acts as a template for the virus to replicate by synthesizing more copies of itself within the host plant cell. TMV remains an important model system for understanding viral structure and replication.
DNA replication is the process by which DNA is doubled. It occurs in three stages: initiation, elongation, and termination. In initiation, initiator proteins recruit replication proteins to origins of replication, unwinding the DNA helix. DNA primase synthesizes RNA primers, and DNA polymerase extends these primers to replicate the DNA. During elongation, leading strand replication occurs continuously while lagging strand replication occurs in fragments called Okazaki fragments. Termination occurs when replication forks meet or reach chromosome ends.
Viruses consist of genetic material surrounded by a protein coat. They can have DNA or RNA as their genetic material and come in various shapes. The document discusses the structure and classification of viruses. It describes their components, sizes, morphologies like helical and icosahedral shapes. It provides examples of plant, animal, and bacterial viruses. It specifically examines the structure and replication of Cauliflower Mosaic Virus, a plant virus with circular double-stranded DNA genome.
Satellite viruses are sub-viral agents that depend on a helper virus for replication. The first reported satellite virus was Tobacco necrosis satellite virus. Satellite viruses contain nucleic acids enclosed in a protein coat and lack genes for replication. Satellite genomes can be single-stranded RNA, DNA, or circular RNA.
Satellite RNAs are small, linear or circular RNA strands found in certain multicomponent virus particles. They do not encode their own coat protein and depend on a helper virus for replication and encapsidation.
Viroids were discovered in 1971 and are small, circular, naked RNA molecules that replicate independently using host polymerases. Well-studied viroids include potato spindle tuber viroid and av
1. DNA replication begins with the unwinding of the DNA double helix by the helicase enzyme. This exposes the two strands of DNA to serve as templates for DNA synthesis.
2. RNA primers are synthesized by the primase enzyme and DNA polymerase adds complementary nucleotides to the 3' end of each primer, elongating it into DNA.
3. The leading strand is synthesized continuously in the 5' to 3' direction while the lagging strand is synthesized in fragments called Okazaki fragments which are later joined by DNA ligase.
4. Several enzymes are involved including DNA polymerase, ligase, helicase, topoisomerase and others to accurately and efficiently copy DNA. DNA replication ensures faithful transmission of
Transcription is the process by which RNA is synthesized from a DNA template by RNA polymerase. It involves initiation at a promoter region, elongation as nucleotides are added to the growing RNA strand, and termination. While similar to DNA replication, transcription only uses one DNA strand as a template and does not require primers.
INTRODUCTION:
The first plant virus shown to have a DNA genome and the first shown to replicate by reverse transcription.
Worldwide but only causes significantly losses locally.
It is transmitted by aphids .
Type member of the Caulimovirus genus, contains 11 species and 6 possible members.
significantly impact on plant virology and plant molecular biology.
The virus is an important source of gene regulatory elements, used exclusively in the genetic manipulation of plants.
STRUCTURE:Icosachedral with a diameter of 52Â nm built from 420 capsid protein subunits.
It contains a circular double-stranded DNA molecule of about 8.0 kB .
Dna is interrupted by sitespecific discontinuties resulting from its replication by reverse transcription.
After entering the host, the single stranded nicks in the viral DNA are repaired, forming a supercoiled molecule that binds to histones.
DNA is transcriped into a full length .
Replication
Risk Factors:The Cauliflower mosaic virus promoter (CaMV 35S) is used in most transgenic crops to activate foreign genes which have been artificially inserted into the host plant. It is inserted into transgenic plants in a form which is different from that found when it is present in its natural Brassica plant hosts. This enables it to operate in a wide range of host-organism environments which would otherwise not be possible.
Viroids are the smallest known agents of infectious disease that cause disease in plants. They are composed of short strands of circular, single-stranded RNA that can self-replicate using the host cell's machinery. In 1971, viroids were discovered by Theodor Diener who found an acellular particle that infected potato plants, causing tuber deformities. There are 30 known viroid species classified into two families based on their structure and composition. Viroids can infect a wide range of plants such as potatoes, coconut palms, avocados, and citrus trees, causing diseases marked by symptoms like stunting, chlorosis, and fruit deformities.
This document discusses viroids, virusoids, and prions. It defines viroids as small, circular, single-stranded RNA molecules without a protein coat that can infect plants. Viroids were first reported in 1971 and the most studied is the Potato Spindle Tuber Viroid. Virusoids are also circular single-stranded RNAs that depend on plant viruses for replication and encapsidation. Prions are small infectious particles composed of abnormally folded protein that can transmit their misfolded shape to normal variants of the same protein.
Translation is the process by which the genetic code carried by mRNA is used to synthesize proteins. It involves three main steps - initiation, elongation, and termination. During initiation, the small and large ribosomal subunits assemble around the mRNA along with initiator tRNA and other factors. In elongation, tRNAs bring amino acids to the ribosome according to the mRNA codons, and peptide bonds form between them. Termination occurs when a stop codon enters the A site and causes the release of the completed protein chain.
The document discusses transcription in prokaryotes and eukaryotes. In prokaryotes, RNA polymerase binds to promoter sequences and transcribes DNA into RNA through initiation, elongation, and termination. Transcription requires RNA polymerase and proceeds similarly in eukaryotes but involves multiple RNA polymerases and occurs in the nucleus. Eukaryotic transcription is more complex, utilizing regulatory sequences, transcription factors, and RNA processing to modify pre-mRNA into mature mRNA through splicing, capping, polyadenylation, and other modifications. Mutations can affect splicing and cause genetic disorders like beta-thalassemia.
Watson and Crick proposed a model of DNA structure in 1953 as a double helix with two antiparallel strands coiled around the same axis. Each strand consists of alternating deoxyribose and phosphate groups with purine or pyrimidine bases stacked inside. Adenine always pairs with thymine via two hydrogen bonds and guanine pairs with cytosine via three hydrogen bonds. Their model explained experimental X-ray diffraction data and Chargaff's rules of base equivalence. The discovery revolutionized our understanding of genetics and heredity.
This document discusses the central dogma of biology and the process of transcription. It describes the three main steps of transcription - initiation, elongation, and termination. Initiation involves the RNA polymerase binding to the promoter sequence on DNA and separating the DNA strands to form an open complex. Elongation is the addition of nucleotides to synthesize RNA. Termination can occur via either Rho-independent or Rho-dependent mechanisms, with the former utilizing a terminator sequence and hairpin structure in the RNA and the latter involving the Rho protein.
The base sequence information present in the gene (DNA) is copied into an RNA molecule, which directly participates in protein synthesis and provides information for amino acid sequence of the protein. This RNA molecule is called messenger RNA or mRNA. The process of production of RNA copy of a DNA sequence is called transcription; this reaction is catalyzed by DNA-directed RNA polymerase, or simply RNA polymerase.
DNA repair mechanisms in prokaryotes involve direct repair, excision repair, and mismatch repair. Direct repair converts damaged nucleotides directly back to their original structure using enzymes like photolyase. Excision repair removes damaged sections of DNA through base excision repair which removes single damaged bases using glycosylases and AP endonucleases, or nucleotide excision repair which removes short oligonucleotides. Mismatch repair recognizes and fixes errors made during DNA replication by distinguishing the parental DNA strands and excising the newly synthesized strand containing mistakes.
RNA is one of the major biological macromolecules essential for life. It has several types that serve different functions. Messenger RNA (mRNA) carries genetic information from DNA to the ribosomes for protein synthesis. Ribosomal RNA (rRNA) is the catalytic component of ribosomes and is involved in protein translation. Transfer RNA (tRNA) transfers specific amino acids to the growing polypeptide chain during translation.
Viruses are the smallest infectious agents that can only replicate inside living host cells. They are metabolically inert and made up of either DNA or RNA surrounded by a protein coat called a capsid. Some viruses have an outer envelope as well. Viruses come in different shapes, sizes and structures depending on the symmetry of their capsids. They infect plants, animals and bacteria. Viruses replicate through lytic and lysogenic cycles where they take over the host cell machinery to produce new virus particles. While they exhibit some living properties like mutation and existing in different strains, viruses still lack many cellular functions and rely entirely on host cells for reproduction.
Viriods are small circular RNA molecules without a protein coat that infect plants and animals. They replicate by hijacking the host's machinery and can cause diseases like potato spindle tuber disease in plants and Hepatitis D in humans. Prions are infectious protein particles that cause neurodegenerative diseases by changing the folding of normal host proteins. Examples include scrapie in sheep and mad cow disease in cattle. They are transmitted through ingestion and cause diseases by triggering apoptosis in the brain.
• Plasmids are extra-chromosomal genetic elements that replicate independently of the host chromosome.
• They are small, circular (some are linear), double-stranded DNA molecules that exist in bacterial cells and in some eukaryotes.
Eukaryotic transcription is carried out in the nucleus of the cell and proceeds in three sequential stages: initiation, elongation, and termination. Eukaryotes require transcription factors to first bind to the promoter region and then help recruit the appropriate polymerase.
1. The document discusses transcription, the process by which RNA is synthesized using DNA as a template.
2. There are three main types of RNA - mRNA, tRNA, and rRNA - which have different functions like encoding proteins, transporting amino acids, and constituting ribosomes.
3. Transcription involves initiation, elongation, and termination stages. Initiation requires promoters, elongation uses RNA polymerase to add nucleotides, and termination ends RNA synthesis.
This document discusses the discovery and structure of viruses. It describes how Ivanovsky and Beijerinck discovered viruses through filtration experiments in the late 1800s. Viruses were found to be filterable, invisible agents that could not be grown in culture. The structure of viruses is then explained, noting they contain nucleic acids surrounded by a protein capsid, and some have an outer envelope. Viruses are much smaller than bacteria and lack cellular structures like organelles.
Viroids are small, circular, non-encapsidated RNA molecules that infect plants and cause disease. They consist solely of nucleic acid and replicate autonomously using host cell machinery. Viroids range in size from 250-400 nucleotides and have various pathogenic effects on infected plants such as distorted growth and reduced yields. They replicate through rolling circle mechanisms using host RNA polymerases and can move systemically within the plant through the phloem. While most viroids only infect plants, the hepatitis delta virus is a human pathogen that requires hepatitis B for infection.
Cauliflower Mosaic Virus is a pararetrovirus that infects plants in the brassicaceae family like cauliflower. It has an icosahedral capsid containing a circular double stranded DNA genome around 80kb in size. The virus replicates through reverse transcription, with its DNA entering the nucleus and being transcribed by the host polymerase. The virus has several open reading frames that encode for structural, movement and other proteins. While it can be used as a vector to insert foreign genes into plants, its capacity is limited to a few hundred nucleotides before the foreign DNA is expelled.
1. There are four main models of DNA replication: rolling circle replication, theta replication, bidirectional replication of linear DNA, and telomere replication.
2. Rolling circle replication involves nicking circular DNA and using one strand as a template to produce multiple copies of the original circular DNA.
3. Theta replication occurs in prokaryotes and involves unwinding circular DNA at an origin of replication and replicating bi-directionally to form a theta-shaped structure.
4. Bidirectional replication of linear DNA involves unwinding DNA at origins of replication and using leading and lagging strand synthesis to replicate in both directions until the ends of the linear genome are reached.
Tobacco mosaic virus (TMV) is one of the most damaging viruses of plants. It causes mosaic patterns and distortions on the leaves of tobacco and other dicotyledonous plants. The virus remains active in plant juice for over 25 years and is transmitted mechanically through contact. Control methods include removing infected plant debris, practicing sanitation to prevent mechanical transmission, and using virus-free seed or transplants.
RNA differs from DNA in its structure and functions. It is single-stranded and can fold into complex shapes that allow it to perform catalytic functions. There are several types of RNA including ribosomal RNA, transfer RNA, and messenger RNA. Ribosomal RNA makes up the ribosome and facilitates protein synthesis. Transfer RNA transports amino acids to the ribosome during protein synthesis. Messenger RNA carries the coding sequence for proteins. RNA plays key roles in regulating gene expression through microRNAs, small interfering RNAs, and other regulatory RNAs.
RNA has several types that serve different functions:
- Messenger RNA (mRNA) carries genetic information from DNA in the nucleus to the ribosome where protein is synthesized. It is single-stranded and contains a 5' cap and 3' poly-A tail.
- Transfer RNA (tRNA) transports specific amino acids to the ribosome and pairs them with mRNA codons during protein translation. It has a cloverleaf secondary structure.
- Ribosomal RNA (rRNA) is a major component of ribosomes and facilitates protein synthesis by providing the structural scaffold for the ribosome.
Viroids are the smallest known agents of infectious disease that cause disease in plants. They are composed of short strands of circular, single-stranded RNA that can self-replicate using the host cell's machinery. In 1971, viroids were discovered by Theodor Diener who found an acellular particle that infected potato plants, causing tuber deformities. There are 30 known viroid species classified into two families based on their structure and composition. Viroids can infect a wide range of plants such as potatoes, coconut palms, avocados, and citrus trees, causing diseases marked by symptoms like stunting, chlorosis, and fruit deformities.
This document discusses viroids, virusoids, and prions. It defines viroids as small, circular, single-stranded RNA molecules without a protein coat that can infect plants. Viroids were first reported in 1971 and the most studied is the Potato Spindle Tuber Viroid. Virusoids are also circular single-stranded RNAs that depend on plant viruses for replication and encapsidation. Prions are small infectious particles composed of abnormally folded protein that can transmit their misfolded shape to normal variants of the same protein.
Translation is the process by which the genetic code carried by mRNA is used to synthesize proteins. It involves three main steps - initiation, elongation, and termination. During initiation, the small and large ribosomal subunits assemble around the mRNA along with initiator tRNA and other factors. In elongation, tRNAs bring amino acids to the ribosome according to the mRNA codons, and peptide bonds form between them. Termination occurs when a stop codon enters the A site and causes the release of the completed protein chain.
The document discusses transcription in prokaryotes and eukaryotes. In prokaryotes, RNA polymerase binds to promoter sequences and transcribes DNA into RNA through initiation, elongation, and termination. Transcription requires RNA polymerase and proceeds similarly in eukaryotes but involves multiple RNA polymerases and occurs in the nucleus. Eukaryotic transcription is more complex, utilizing regulatory sequences, transcription factors, and RNA processing to modify pre-mRNA into mature mRNA through splicing, capping, polyadenylation, and other modifications. Mutations can affect splicing and cause genetic disorders like beta-thalassemia.
Watson and Crick proposed a model of DNA structure in 1953 as a double helix with two antiparallel strands coiled around the same axis. Each strand consists of alternating deoxyribose and phosphate groups with purine or pyrimidine bases stacked inside. Adenine always pairs with thymine via two hydrogen bonds and guanine pairs with cytosine via three hydrogen bonds. Their model explained experimental X-ray diffraction data and Chargaff's rules of base equivalence. The discovery revolutionized our understanding of genetics and heredity.
This document discusses the central dogma of biology and the process of transcription. It describes the three main steps of transcription - initiation, elongation, and termination. Initiation involves the RNA polymerase binding to the promoter sequence on DNA and separating the DNA strands to form an open complex. Elongation is the addition of nucleotides to synthesize RNA. Termination can occur via either Rho-independent or Rho-dependent mechanisms, with the former utilizing a terminator sequence and hairpin structure in the RNA and the latter involving the Rho protein.
The base sequence information present in the gene (DNA) is copied into an RNA molecule, which directly participates in protein synthesis and provides information for amino acid sequence of the protein. This RNA molecule is called messenger RNA or mRNA. The process of production of RNA copy of a DNA sequence is called transcription; this reaction is catalyzed by DNA-directed RNA polymerase, or simply RNA polymerase.
DNA repair mechanisms in prokaryotes involve direct repair, excision repair, and mismatch repair. Direct repair converts damaged nucleotides directly back to their original structure using enzymes like photolyase. Excision repair removes damaged sections of DNA through base excision repair which removes single damaged bases using glycosylases and AP endonucleases, or nucleotide excision repair which removes short oligonucleotides. Mismatch repair recognizes and fixes errors made during DNA replication by distinguishing the parental DNA strands and excising the newly synthesized strand containing mistakes.
RNA is one of the major biological macromolecules essential for life. It has several types that serve different functions. Messenger RNA (mRNA) carries genetic information from DNA to the ribosomes for protein synthesis. Ribosomal RNA (rRNA) is the catalytic component of ribosomes and is involved in protein translation. Transfer RNA (tRNA) transfers specific amino acids to the growing polypeptide chain during translation.
Viruses are the smallest infectious agents that can only replicate inside living host cells. They are metabolically inert and made up of either DNA or RNA surrounded by a protein coat called a capsid. Some viruses have an outer envelope as well. Viruses come in different shapes, sizes and structures depending on the symmetry of their capsids. They infect plants, animals and bacteria. Viruses replicate through lytic and lysogenic cycles where they take over the host cell machinery to produce new virus particles. While they exhibit some living properties like mutation and existing in different strains, viruses still lack many cellular functions and rely entirely on host cells for reproduction.
Viriods are small circular RNA molecules without a protein coat that infect plants and animals. They replicate by hijacking the host's machinery and can cause diseases like potato spindle tuber disease in plants and Hepatitis D in humans. Prions are infectious protein particles that cause neurodegenerative diseases by changing the folding of normal host proteins. Examples include scrapie in sheep and mad cow disease in cattle. They are transmitted through ingestion and cause diseases by triggering apoptosis in the brain.
• Plasmids are extra-chromosomal genetic elements that replicate independently of the host chromosome.
• They are small, circular (some are linear), double-stranded DNA molecules that exist in bacterial cells and in some eukaryotes.
Eukaryotic transcription is carried out in the nucleus of the cell and proceeds in three sequential stages: initiation, elongation, and termination. Eukaryotes require transcription factors to first bind to the promoter region and then help recruit the appropriate polymerase.
1. The document discusses transcription, the process by which RNA is synthesized using DNA as a template.
2. There are three main types of RNA - mRNA, tRNA, and rRNA - which have different functions like encoding proteins, transporting amino acids, and constituting ribosomes.
3. Transcription involves initiation, elongation, and termination stages. Initiation requires promoters, elongation uses RNA polymerase to add nucleotides, and termination ends RNA synthesis.
This document discusses the discovery and structure of viruses. It describes how Ivanovsky and Beijerinck discovered viruses through filtration experiments in the late 1800s. Viruses were found to be filterable, invisible agents that could not be grown in culture. The structure of viruses is then explained, noting they contain nucleic acids surrounded by a protein capsid, and some have an outer envelope. Viruses are much smaller than bacteria and lack cellular structures like organelles.
Viroids are small, circular, non-encapsidated RNA molecules that infect plants and cause disease. They consist solely of nucleic acid and replicate autonomously using host cell machinery. Viroids range in size from 250-400 nucleotides and have various pathogenic effects on infected plants such as distorted growth and reduced yields. They replicate through rolling circle mechanisms using host RNA polymerases and can move systemically within the plant through the phloem. While most viroids only infect plants, the hepatitis delta virus is a human pathogen that requires hepatitis B for infection.
Cauliflower Mosaic Virus is a pararetrovirus that infects plants in the brassicaceae family like cauliflower. It has an icosahedral capsid containing a circular double stranded DNA genome around 80kb in size. The virus replicates through reverse transcription, with its DNA entering the nucleus and being transcribed by the host polymerase. The virus has several open reading frames that encode for structural, movement and other proteins. While it can be used as a vector to insert foreign genes into plants, its capacity is limited to a few hundred nucleotides before the foreign DNA is expelled.
1. There are four main models of DNA replication: rolling circle replication, theta replication, bidirectional replication of linear DNA, and telomere replication.
2. Rolling circle replication involves nicking circular DNA and using one strand as a template to produce multiple copies of the original circular DNA.
3. Theta replication occurs in prokaryotes and involves unwinding circular DNA at an origin of replication and replicating bi-directionally to form a theta-shaped structure.
4. Bidirectional replication of linear DNA involves unwinding DNA at origins of replication and using leading and lagging strand synthesis to replicate in both directions until the ends of the linear genome are reached.
Tobacco mosaic virus (TMV) is one of the most damaging viruses of plants. It causes mosaic patterns and distortions on the leaves of tobacco and other dicotyledonous plants. The virus remains active in plant juice for over 25 years and is transmitted mechanically through contact. Control methods include removing infected plant debris, practicing sanitation to prevent mechanical transmission, and using virus-free seed or transplants.
RNA differs from DNA in its structure and functions. It is single-stranded and can fold into complex shapes that allow it to perform catalytic functions. There are several types of RNA including ribosomal RNA, transfer RNA, and messenger RNA. Ribosomal RNA makes up the ribosome and facilitates protein synthesis. Transfer RNA transports amino acids to the ribosome during protein synthesis. Messenger RNA carries the coding sequence for proteins. RNA plays key roles in regulating gene expression through microRNAs, small interfering RNAs, and other regulatory RNAs.
RNA has several types that serve different functions:
- Messenger RNA (mRNA) carries genetic information from DNA in the nucleus to the ribosome where protein is synthesized. It is single-stranded and contains a 5' cap and 3' poly-A tail.
- Transfer RNA (tRNA) transports specific amino acids to the ribosome and pairs them with mRNA codons during protein translation. It has a cloverleaf secondary structure.
- Ribosomal RNA (rRNA) is a major component of ribosomes and facilitates protein synthesis by providing the structural scaffold for the ribosome.
The document discusses nucleic acids and RNA. It defines nucleic acids as macromolecules composed of nucleotide chains, with each nucleotide containing a nitrogenous base, pentose sugar, and phosphate group. RNA is described as a type of nucleic acid that contains ribose rather than deoxyribose and uracil instead of thymine. The document outlines the three main types of RNA - messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA) - and their roles in protein synthesis.
RNA is a molecule that is present in most living organisms and viruses. It is made up of nucleotides containing ribose sugars attached to nitrogenous bases and phosphate groups. There are three major types of RNA: messenger RNA (mRNA) which carries DNA instructions to the ribosome, ribosomal RNA (rRNA) which forms the ribosome where protein synthesis occurs, and transfer RNA (tRNA) which transports amino acids to the ribosome during protein synthesis. The document further describes the structure, function and roles of mRNA, rRNA, tRNA as well as other types of RNA like microRNA. It also explains the wobble hypothesis regarding degeneracy in the genetic code.
Both RNA and DNA are made of nucleotides and take similar shapes. Both contain five-carbon sugars, phosphate groups, and nucleobases (nitrogenous bases). They both play important roles in protein synthesis. DNA has the five-carbon sugar deoxyribose and RNA has the five-carbon sugar ribose, hence their names
Structure of dna and rna and their differenceSrimathiDS
DNA and RNA are nucleic acids that store and transmit genetic information. DNA exists as a double-stranded helix located in chromosomes, while RNA is single-stranded and can be found both inside and outside the nucleus. The key differences are that DNA contains the sugar deoxyribose and the base thymine, making it more stable for long-term storage of genetic material in the nucleus. RNA contains the sugar ribose and the base uracil instead of thymine, making it better suited for its short-term roles in protein synthesis by transferring genetic information from DNA to ribosomes.
The central dogma of molecular biology describes the flow of genetic information from DNA to RNA to protein. DNA contains the genetic code in nucleotide base pairs. During transcription, a complementary mRNA copy of a DNA sequence is generated. The mRNA is then modified before undergoing translation, where ribosomes read the mRNA codons to assemble amino acids into proteins according to the genetic code. This process allows genetic information stored in DNA to be converted into functional proteins.
RNA has several important functions and types. It has a similar structure to DNA but contains ribose rather than deoxyribose. The four main types of RNA are messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and catalytic RNA. mRNA carries protein instructions from DNA to ribosomes. tRNA transfers amino acids to the ribosome during protein synthesis. rRNA is the main component of ribosomes and helps in protein synthesis. RNA can also function as an enzyme.
The document summarizes the cloverleaf model of tRNA secondary structure. It describes how the tRNA molecule folds into four double helical segments connected by single-stranded linking sequences. It notes that the two ends form the amino acid acceptor stem, with a single-stranded CCA sequence protruding from the 3' end to which the amino acid is attached. The other three arms are the TPsiC arm, variable arm, and anticodon arm, in clockwise order.
Secondary and tertiary structure of RNARajwantiSaran
This document discusses the secondary and tertiary structures of RNA. It begins by defining RNA and its types, including mRNA, rRNA, tRNA, snRNAs, miRNAs, siRNAs and others. It then explains the primary, secondary and tertiary structures of RNA. The secondary structure involves base pairing to form stems and loops, including bulge loops, internal loops, multi loops and hairpin loops. Tertiary structure involves interactions between these secondary structure elements. Specific interactions discussed include coaxial stacking and the role of magnesium ions. The structures are important for RNA's catalytic, regulatory and structural roles in cells.
This is the whole document of the slide presentation NUCLEIC ACID: THE RNA. This full document contains all the information and explanation of the slide presentation.
Ribosomal ribonucleic acid (rRNA) is a type of non-coding RNA that is the primary component of ribosomes and essential for protein synthesis. rRNA is transcribed from ribosomal DNA and binds with ribosomal proteins to form the small and large ribosomal subunits. rRNA folds into stem loops that allow it to interact with mRNA and tRNA to catalyze the translation of mRNA into proteins. rRNA makes up about 80% of cellular RNA and plays critical roles in the ribosome's peptidyl transferase activity through conserved sequences and structures.
The document discusses the structure and function of nucleic acids and their components. It covers the following key points:
1. Nucleic acids are made of nucleotides, which consist of a nucleoside (a nitrogenous base linked to a 5-carbon sugar) and one or more phosphate groups. The bases are either pyrimidines or purines.
2. DNA contains the bases adenine, guanine, cytosine, and thymine, while RNA contains adenine, guanine, cytosine, and uracil instead of thymine.
3. Nucleotides join together via phosphodiester bonds between the 3' carbon of one sugar and the 5' carbon of the next,
This document provides information about RNA and different types of RNA. It discusses that RNA, like DNA, is composed of nucleotides joined by phosphodiester bonds, but contains ribose instead of deoxyribose and uracil instead of thymine. There are two main types of RNA - genetic RNA that acts as the genetic material of some viruses, and non-genetic RNA involved in protein synthesis, including messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). The document describes the structure and functions of mRNA and tRNA in protein synthesis.
DNA is a molecule that contains the genetic instructions used in the development and functioning of all living organisms.It consists of two long strands that coil around each other to form a double helix structure.The four nucleotides that make up DNA are adenine (A), thymine (T), guanine (G), and cytosine (C).Adenine pairs with thymine, and guanine pairs with cytosine in DNA.RNA (Ribonucleic Acid):
DNA vs. RNA 5 Key Differences and Comparison.pdfMichelleRojas57
DNA stores genetic information in the nucleus and is more stable than RNA. RNA exists in several forms and has different functions - messenger RNA (mRNA) transports genetic code from DNA to ribosomes, transfer RNA (tRNA) brings amino acids to ribosomes for protein production, and ribosomal RNA (rRNA) is a component of ribosomes. The key differences between DNA and RNA are their sugar composition, with DNA containing deoxyribose and RNA containing ribose; their fourth bases, with DNA containing thymine and RNA containing uracil; and their locations in the cell.
Friedrich Miescher discovered nucleic acids in 1869. There are two main types of nucleic acids: DNA and RNA. DNA is made of nucleotides containing the bases adenine, cytosine, guanine, and thymine. It takes the form of a double helix with the bases pairing between strands. In 1953, Watson and Crick proposed the double helix structure of DNA based on X-ray crystallography data. RNA is single-stranded and contains the bases adenine, cytosine, guanine, and uracil. There are several types of RNA including messenger RNA, ribosomal RNA, and transfer RNA that help in protein synthesis.
The document discusses nucleic acids, which are capable of yielding phosphoric acid, sugars, and organic bases upon breakdown. The two main classes are DNA and RNA. DNA is the genetic material found in all living organisms and some viruses. It is made of nucleotides containing the bases adenine, guanine, cytosine, and thymine. RNA plays an important role in protein synthesis and is the genetic material of some viruses. It contains the same bases as DNA except thymine is replaced with uracil. The structures of DNA, RNA, and their components like nucleotides, purines, pyrimidines, and phosphodiester bonds are described in detail.
There are two main types of nucleic acids: DNA and RNA. DNA is found in the nucleus and contains the genetic material. RNA is found in the cytoplasm and is involved in protein synthesis. Both DNA and RNA are made up of nucleotides which contain a sugar, phosphate, and a nitrogenous base. DNA has the bases adenine, guanine, cytosine, and thymine while RNA contains adenine, guanine, cytosine, and uracil instead of thymine. DNA exists as a double helix structure within the nucleus that is wrapped around histone proteins to form nucleosomes and chromosomes to tightly package the genetic material. RNA plays a key role in protein synthesis by carrying codons from DNA in the nucleus to
The Central Dogma of Biology describes the process of protein synthesis from DNA to RNA to protein. DNA is transcribed into messenger RNA (mRNA) in the cell nucleus. The mRNA then exits the nucleus and the process of translation occurs in the cytoplasm. During translation, ribosomes use the mRNA to assemble amino acids into a protein chain based on the mRNA codon sequence. Transfer RNA (tRNA) molecules match their anticodons to the mRNA codons and add the corresponding amino acids to the growing protein chain. Eventually a whole protein is produced based on the DNA code provided in the gene.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...Sérgio Sacani
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
ESR spectroscopy in liquid food and beverages.pptxPRIYANKA PATEL
With increasing population, people need to rely on packaged food stuffs. Packaging of food materials requires the preservation of food. There are various methods for the treatment of food to preserve them and irradiation treatment of food is one of them. It is the most common and the most harmless method for the food preservation as it does not alter the necessary micronutrients of food materials. Although irradiated food doesn’t cause any harm to the human health but still the quality assessment of food is required to provide consumers with necessary information about the food. ESR spectroscopy is the most sophisticated way to investigate the quality of the food and the free radicals induced during the processing of the food. ESR spin trapping technique is useful for the detection of highly unstable radicals in the food. The antioxidant capability of liquid food and beverages in mainly performed by spin trapping technique.
Unlocking the mysteries of reproduction: Exploring fecundity and gonadosomati...AbdullaAlAsif1
The pygmy halfbeak Dermogenys colletei, is known for its viviparous nature, this presents an intriguing case of relatively low fecundity, raising questions about potential compensatory reproductive strategies employed by this species. Our study delves into the examination of fecundity and the Gonadosomatic Index (GSI) in the Pygmy Halfbeak, D. colletei (Meisner, 2001), an intriguing viviparous fish indigenous to Sarawak, Borneo. We hypothesize that the Pygmy halfbeak, D. colletei, may exhibit unique reproductive adaptations to offset its low fecundity, thus enhancing its survival and fitness. To address this, we conducted a comprehensive study utilizing 28 mature female specimens of D. colletei, carefully measuring fecundity and GSI to shed light on the reproductive adaptations of this species. Our findings reveal that D. colletei indeed exhibits low fecundity, with a mean of 16.76 ± 2.01, and a mean GSI of 12.83 ± 1.27, providing crucial insights into the reproductive mechanisms at play in this species. These results underscore the existence of unique reproductive strategies in D. colletei, enabling its adaptation and persistence in Borneo's diverse aquatic ecosystems, and call for further ecological research to elucidate these mechanisms. This study lends to a better understanding of viviparous fish in Borneo and contributes to the broader field of aquatic ecology, enhancing our knowledge of species adaptations to unique ecological challenges.
Describing and Interpreting an Immersive Learning Case with the Immersion Cub...Leonel Morgado
Current descriptions of immersive learning cases are often difficult or impossible to compare. This is due to a myriad of different options on what details to include, which aspects are relevant, and on the descriptive approaches employed. Also, these aspects often combine very specific details with more general guidelines or indicate intents and rationales without clarifying their implementation. In this paper we provide a method to describe immersive learning cases that is structured to enable comparisons, yet flexible enough to allow researchers and practitioners to decide which aspects to include. This method leverages a taxonomy that classifies educational aspects at three levels (uses, practices, and strategies) and then utilizes two frameworks, the Immersive Learning Brain and the Immersion Cube, to enable a structured description and interpretation of immersive learning cases. The method is then demonstrated on a published immersive learning case on training for wind turbine maintenance using virtual reality. Applying the method results in a structured artifact, the Immersive Learning Case Sheet, that tags the case with its proximal uses, practices, and strategies, and refines the free text case description to ensure that matching details are included. This contribution is thus a case description method in support of future comparative research of immersive learning cases. We then discuss how the resulting description and interpretation can be leveraged to change immersion learning cases, by enriching them (considering low-effort changes or additions) or innovating (exploring more challenging avenues of transformation). The method holds significant promise to support better-grounded research in immersive learning.
ESPP presentation to EU Waste Water Network, 4th June 2024 “EU policies driving nutrient removal and recycling
and the revised UWWTD (Urban Waste Water Treatment Directive)”
When I was asked to give a companion lecture in support of ‘The Philosophy of Science’ (https://shorturl.at/4pUXz) I decided not to walk through the detail of the many methodologies in order of use. Instead, I chose to employ a long standing, and ongoing, scientific development as an exemplar. And so, I chose the ever evolving story of Thermodynamics as a scientific investigation at its best.
Conducted over a period of >200 years, Thermodynamics R&D, and application, benefitted from the highest levels of professionalism, collaboration, and technical thoroughness. New layers of application, methodology, and practice were made possible by the progressive advance of technology. In turn, this has seen measurement and modelling accuracy continually improved at a micro and macro level.
Perhaps most importantly, Thermodynamics rapidly became a primary tool in the advance of applied science/engineering/technology, spanning micro-tech, to aerospace and cosmology. I can think of no better a story to illustrate the breadth of scientific methodologies and applications at their best.
Authoring a personal GPT for your research and practice: How we created the Q...Leonel Morgado
Thematic analysis in qualitative research is a time-consuming and systematic task, typically done using teams. Team members must ground their activities on common understandings of the major concepts underlying the thematic analysis, and define criteria for its development. However, conceptual misunderstandings, equivocations, and lack of adherence to criteria are challenges to the quality and speed of this process. Given the distributed and uncertain nature of this process, we wondered if the tasks in thematic analysis could be supported by readily available artificial intelligence chatbots. Our early efforts point to potential benefits: not just saving time in the coding process but better adherence to criteria and grounding, by increasing triangulation between humans and artificial intelligence. This tutorial will provide a description and demonstration of the process we followed, as two academic researchers, to develop a custom ChatGPT to assist with qualitative coding in the thematic data analysis process of immersive learning accounts in a survey of the academic literature: QUAL-E Immersive Learning Thematic Analysis Helper. In the hands-on time, participants will try out QUAL-E and develop their ideas for their own qualitative coding ChatGPT. Participants that have the paid ChatGPT Plus subscription can create a draft of their assistants. The organizers will provide course materials and slide deck that participants will be able to utilize to continue development of their custom GPT. The paid subscription to ChatGPT Plus is not required to participate in this workshop, just for trying out personal GPTs during it.
The debris of the ‘last major merger’ is dynamically youngSérgio Sacani
The Milky Way’s (MW) inner stellar halo contains an [Fe/H]-rich component with highly eccentric orbits, often referred to as the
‘last major merger.’ Hypotheses for the origin of this component include Gaia-Sausage/Enceladus (GSE), where the progenitor
collided with the MW proto-disc 8–11 Gyr ago, and the Virgo Radial Merger (VRM), where the progenitor collided with the
MW disc within the last 3 Gyr. These two scenarios make different predictions about observable structure in local phase space,
because the morphology of debris depends on how long it has had to phase mix. The recently identified phase-space folds in Gaia
DR3 have positive caustic velocities, making them fundamentally different than the phase-mixed chevrons found in simulations
at late times. Roughly 20 per cent of the stars in the prograde local stellar halo are associated with the observed caustics. Based
on a simple phase-mixing model, the observed number of caustics are consistent with a merger that occurred 1–2 Gyr ago.
We also compare the observed phase-space distribution to FIRE-2 Latte simulations of GSE-like mergers, using a quantitative
measurement of phase mixing (2D causticality). The observed local phase-space distribution best matches the simulated data
1–2 Gyr after collision, and certainly not later than 3 Gyr. This is further evidence that the progenitor of the ‘last major merger’
did not collide with the MW proto-disc at early times, as is thought for the GSE, but instead collided with the MW disc within
the last few Gyr, consistent with the body of work surrounding the VRM.
Remote Sensing and Computational, Evolutionary, Supercomputing, and Intellige...University of Maribor
Slides from talk:
Aleš Zamuda: Remote Sensing and Computational, Evolutionary, Supercomputing, and Intelligent Systems.
11th International Conference on Electrical, Electronics and Computer Engineering (IcETRAN), Niš, 3-6 June 2024
Inter-Society Networking Panel GRSS/MTT-S/CIS Panel Session: Promoting Connection and Cooperation
https://www.etran.rs/2024/en/home-english/
Phenomics assisted breeding in crop improvementIshaGoswami9
As the population is increasing and will reach about 9 billion upto 2050. Also due to climate change, it is difficult to meet the food requirement of such a large population. Facing the challenges presented by resource shortages, climate
change, and increasing global population, crop yield and quality need to be improved in a sustainable way over the coming decades. Genetic improvement by breeding is the best way to increase crop productivity. With the rapid progression of functional
genomics, an increasing number of crop genomes have been sequenced and dozens of genes influencing key agronomic traits have been identified. However, current genome sequence information has not been adequately exploited for understanding
the complex characteristics of multiple gene, owing to a lack of crop phenotypic data. Efficient, automatic, and accurate technologies and platforms that can capture phenotypic data that can
be linked to genomics information for crop improvement at all growth stages have become as important as genotyping. Thus,
high-throughput phenotyping has become the major bottleneck restricting crop breeding. Plant phenomics has been defined as the high-throughput, accurate acquisition and analysis of multi-dimensional phenotypes
during crop growing stages at the organism level, including the cell, tissue, organ, individual plant, plot, and field levels. With the rapid development of novel sensors, imaging technology,
and analysis methods, numerous infrastructure platforms have been developed for phenotyping.
1. Assignment no:3 of
Molecularbiology
Topic:Types of RNA And Their Functions
Submitted to:
Muhammad Owais
Submitted by:
Rameen Iqbal
Registration No:
L1F18BSBT0053
Section: B
Table of Contents
Definition:..........................................................................................................................................................................................................................3
History of RNA:.................................................................................................................................................................................................................3
RNA STRUCTURE:.............................................................................................................................................................................................................4
OVERVIEW:..............................................................................................................................................................................................................4
Different Types of RNA Have the Same Basic Structure:..........................................................................................................................................4
2. RNA Assembly Is Unidirectional:...................................................................................................................................................................................6
RNA Can Form Secondary Structures:..........................................................................................................................................................................6
The Secondary and Tertiary Structure of tRNA Enables Protein Synthesis:..........................................................................................................7
RNA FUNCTION: ...............................................................................................................................................................................................................7
Types of RNA and their Functions.................................................................................................................................................................................9
Types of RNA: ...................................................................................................................................................................................................................9
I. Ribosomal RNA ...........................................................................................................................................................................................................9
II. Transfer RNA...............................................................................................................................................................................................................9
III. Small nuclear RNA...................................................................................................................................................................................................9
IV. Guide RNA..................................................................................................................................................................................................................9
V. Small Regulatory RNA ..............................................................................................................................................................................................9
VI. Antisense RNA...........................................................................................................................................................................................................9
VII. Housekeeping RNA ................................................................................................................................................................................................9
Function of Ribosomal RNA: ..........................................................................................................................................................................................9
Small nuclear RNA: ........................................................................................................................................................................................................11
Guide RNA:......................................................................................................................................................................................................................12
Antisense RNAs ..............................................................................................................................................................................................................13
Small Regulatory RNAs..................................................................................................................................................................................................13
House-keeping RNAs .....................................................................................................................................................................................................13
References: .....................................................................................................................................................................................................................14
3. Introduction of RNA (Structure and Nature)
Definition:
RNA or ribonucleic destructive is a polymer of nucleotides that is included a ribose sugar, a phosphate, and
bases, for instance, adenine, guanine, cytosine, and uracil. It expects a fundamental activity in quality
enunciation by going about as the somewhere between the inherited information encoded by DNA and proteins.
As seen in diagram below:
RNA has a structure fundamentallythe same asthat of DNA.The keydistinctioninRNA structure isthatthe ribose sugar
inRNA hasa hydroxyl (- OH) bunchthat ismissinginDNA.
History of RNA:
Nucleic acids were first discovered by Friedrich Miescher in 1868 who called the material as
‘nuclei’ as it was found in the nucleus and this led to the discovery of RNA. The key milestone in
the history of RNA is given below,
In the year 1939, the role of DNA in protein synthesis was postulated.
In the year 1959 Severo Ochoa won the Nobel prize for discovering the RNA synthesis mechanism.
In the year 1965, Robert W. Holley sequences 77 nucleotides of yeast tRNA.
4. Some of the highlights of RNA molecules are given below,
RNA was distinctly different from DNA because of its sensitivity towards alkaline –OH group on the
ribose.
ATP and GTP were to be the main energy source and building blocks for RNA.
Adenine, cytosine and guanine were the three bases common to RNA and DNA while instead of
thymine Uracil is present into the RNA.
RNA STRUCTURE:
OVERVIEW:
The basic structure of RNA includes a five-carbon sugar and one of four nitrogenous bases. But most RNA is
single-relinquished, it can shape complex discretionary and tertiary structures. Such structures accept basic
occupations in the rule of translation and understanding.
Different Types of RNA Have the Same Basic Structure:
There are three essential sorts of ribonucleic destructive (RNA): messenger RNA (mRNA), move RNA (tRNA),
and ribosomal RNA (rRNA). All of the three RNA types contain a single deserted chain of nucleotides. Each
nucleotide is made out of the five-carbon sugar ribose. The carbon particles of ribose are numbered one through
five. Carbon number five passes on a phosphate social occasion and carbon number one a nitrogenous base.
As shown below:
There are four nitrogenous bases in RNA—adenine (A), guanine (G), cytosine (C), and uracil (U). Uracil is the
fundamental base in RNA that is missing in DNA, which uses thymine (T. During interpretation, RNA is mixed
5. from a DNA design reliant on correlative legitimate of the new RNA bases to the DNA bases; A connections to
T, G binds to C, C binds to G, and U binds to A.
As shown in below fig:
Even though RNA is single stranded, most types of RNA molecules show extensive intramolecular base pairing
between complementary sequences within the RNA strand, creating a predictable three-dimensional structure
essential for their function, as shown in below figure:
(a) Ribonucleotides contain the pentose sugar ribose instead of the deoxyribose found in deoxyribonucleotides.
(b) RNA contains the pyrimidine uracil in place of thymine found in DNA.
6. RNA Assembly Is Unidirectional:
Like DNA, abutting nucleotides in RNA are associated together through phosphodiester bonds. These bonds
structure between the phosphate social event of one nucleotide and a hydroxyl (– OH) pack on the ribose of the
touching nucleotide.
This structure advances RNA its directionality—that is, the two pieces of the deals of nucleotides are
remarkable. Carbon number five of ribose passes on an unbound phosphate pack which offers rise to the name
5' end (read five prime). The last ribose at the contrary completion of the nucleotide chain has a free hydroxyl (–
OH) bundle at carbon number 3; subsequently, this completion of the RNA molecule is called 3' end. As
nucleotides are added to the chain during translation, the 5' phosphate social event of the new nucleotide reacts
with the 3' hydroxyl get-together of the creating chain. Thusly, RNA is continually accumulated in the 5' to 3'
course.
RNA Can Form Secondary Structures:
Discretionary structures are confined by indispensable base coordinating between far away nucleotides on a
comparable single-relinquished RNA. Fasten circles are surrounded by relating coordinating of bases inside 5-
10 nucleotides of each other. Stem-circles are encircled by coordinating of bases that are secluded by 50 to
numerous nucleotides. In prokaryotes, these discretionary structures function as transcriptional controllers. For
instance, a catch circle can fill in as an end sign with the ultimate objective that when understanding impetuses
experience this structure, they detach from the mRNA and interpretation stops. Stem-circles or clasp hovers at
the 3' or 5' closes in like manner control mRNA quality in eukaryotes by hindering the definitive of
ribonucleases—exacerbates that degenerate RNA.
Below the secondary structure of RNA.
Discretionary structures can outline progressively jumbled tertiary structures called pseudoknots. Pseudoknots
are surrounded when bases ok locale of assistant structures speak with comparing bases outside the circle.
These tertiary structures expect key employments in RNA structure and limit.
7. The Secondary and Tertiary Structure of tRNA Enables Protein Synthesis:
tRNAs fill in as connector iotas during the translation of mRNA into proteins. Toward one side, tRNAs pass on
an amino destructive. At the far edge, they bind to a mRNA codon—a course of action of three nucleotides that
encodes a specific amino destructive. tRNA particles are regularly 70-80 nucleotides long and overlay into a
stem-circle structure that takes after a cloverleaf. Three of the four stems have circles containing 7-8 bases. The
fourth stem is unlopped and fuses the free 5' and 3' portions of the deals strand. The 3' end goes about as the
amino destructive acceptor site.
The three-dimensional structure of tRNA is L-framed, with the amino destructive confining site toward one side
and an anticodon at the furthest edge. Anticodons are groupings of three nucleotides that are relating to the
mRNA codon. This whimsical condition of the tRNA engages it to bind to ribosomes, where protein
amalgamation occurs.
RNA FUNCTION:
Cells get to the information set aside in DNA by making RNA to organize the mix of proteins through the
method of understanding. Proteins inside a cell have various limits, including building cell structures and filling
in as compound driving forces for cell manufactured reactions that give cells their specific traits. The three
standard sorts of RNA truly connected with protein mix are banner carrier RNA (mRNA), ribosomal RNA
(rRNA), and move RNA (tRNA).
In 1961, French specialists François Jacob and Jacques Monod guessed the nearness of a center individual
among DNA and its protein things, which they called conveyance individual RNA.16 Evidence supporting their
hypothesis was aggregated soon a brief timeframe later exhibiting that information from DNA is transmitted to
the ribosome for protein blend using mRNA. In case DNA fills in as the absolute library of cell information,
mRNA fills in as a duplicate of unequivocal information required at a point in time that fills in as the rules to
make a protein.
The mRNA passes on the message from the DNA, which controls the aggregate of the cell practices in a cell. If
a cell requires a protein to be organized, the quality for this thing is "turned on" and the mRNA is consolidated
through the method of translation. The mRNA by then speaks with ribosomes and other cell equipment to
organize the amalgamation of the protein it encodes during the methodology of translation (see Protein
Synthesis). mRNA is commonly unsafe and temporary in the telephone, especially in prokaryotic cells, ensuring
that proteins are potentially made when required.
In below fig you will see: A generalized illustration of how mRNA and tRNA are used in protein synthesis
within a cell.
rRNA and tRNA are consistent sorts of RNA. In prokaryotes and eukaryotes, tRNA and rRNA are encoded in
the DNA, by then copied into long RNA particles that are cut to release more diminutive pieces containing the
individual create RNA species. In eukaryotes, association, cutting, and get together of rRNA into ribosomes
8. occurs in the nucleolus zone of the center, yet these activities occur in the cytoplasm of prokaryotes. Neither of
these sorts of RNA passes on rules to organize the association of a polypeptide, yet they accept other critical
employments in protein blend.
Ribosomes are made out of rRNA and protein. As its name suggests, rRNA is a critical constituent of
ribosomes, making up to about 60% of the ribosome by mass and giving the territory where the mRNA ties. The
rRNA ensures the most ideal course of action of the mRNA, tRNA, and the ribosomes; the rRNA of the
ribosome also has an enzymatic activity (peptidyl transferase) and catalyzes the advancement of the peptide
bonds between two balanced amino acids during protein association.
Despite the way that rRNA had for a long while been thought to serve essentially a helper work, its reactant
work inside the ribosome was exhibited in 2000.17 Scientists in the exploration places of Thomas Steitz (1940–
) and Peter Moore (1939–) at Yale University had the alternative to come to fruition the ribosome structure from
Haloarcula marismortui, a halophilic archaeon isolated from the Dead Sea. Taking into account the importance
of this work, Steitz shared the 2009 Nobel Prize in Chemistry with various scientists who made immense duties
to the appreciation of ribosome structure.
Move RNA is the third essential sort of RNA and one of the tiniest, normally only 70–90 nucleotides long. It
passes on the correct amino destructive to the site of protein amalgamation in the ribosome. It is the base
coordinating between the tRNA and mRNA that considers the correct amino destructive to be implanted in the
polypeptide chain being fused (as shown in below diagram). Any adjustments in the tRNA or rRNA can achieve
overall issues for the telephone considering the way that both are significant for suitable protein association
A tRNA molecule is a single-stranded molecule that exhibits significant intracellular base pairing, giving it its
characteristic three-dimensional shape. As shown below.
RNA as HereditaryInformation:
Despite the way that RNA doesn't fill in as the inborn information in numerous cells, RNA holds this limit with
regards to certain diseases that don't contain DNA. Appropriately, RNA clearly has the additional capacity to
fill in as innate information. Despite the way that RNA is consistently single relinquished inside cells, there is
colossal grouped assortment in diseases. Rhinoviruses, which cause the typical cold; influenza contaminations;
and the Ebola disease are single-deserted RNA contaminations. Rotaviruses, which cause extraordinary
9. gastroenteritis in adolescents and other immunocompromised individuals, are occasions of twofold surrendered
RNA contaminations. Since twofold surrendered RNA is exceptional in eukaryotic cells, its quality fills in as a
marker of viral malady. The recommendations for a disease having a RNA genome as opposed to a DNA
genome are inspected in more detail in Viruses.
Types of RNA and their Functions
There are many types of RNA, but few are discussed below
Types of RNA:
I. Ribosomal RNA
II. Transfer RNA
III. Small nuclear RNA
IV. Guide RNA
V. Small Regulatory RNA
VI. Antisense RNA
VII. Housekeeping RNA
Function of Ribosomal RNA:
The fundamental limit of rRNA is in protein amalgamation – in authority to separation RNA and move
RNA to ensure that the codon course of action of the mRNA is made an understanding of accurately into
amino destructive gathering in proteins. To achieve this, rRNA has an indisputable three-dimensional
shape including internal circles and helices that makes express goals inside the ribosome – the A, P and
E districts. The P site is for limiting a creating polypeptide, the A site remains a moving toward tRNA
blamed for an amino destructive. After peptide bond improvement, the tRNA ties rapidly to the E site
before leaving the ribosome. What's more rRNA furthermore has goals for authority to some ribosomal
proteins and mindful assessment has separated the stores in both the RNA and protein.
As shown in image below:
10. Ribosomal RNA is also conveyed in every cell of each enduring specie. The progression of the inside
synergist districts is moreover particularly proportioned making rRNA a sublime gadget for the
examination of logical arrangement and phylogenetics. There is a differentiation in the pace of
advancement of developments on a shallow level and within rRNA, and nucleotides drew in with focus
reactant activity, for instance, in the course of action of a peptide bond, appear to have started before the
nearness of life on earth. How much two species differentiate in rRNA groupings can give a better than
average measure of their formative partition.
Various enemy of disease operators target prokaryotic rRNA and starting late the coupling regions for
against contamination specialists, for instance, streptomycin and anti-toxin prescription on rRNA have
been illustrated. It has moreover been exhibited that enemy of microbial check normally starts from
point changes in these coupling goals. For instance, the obstacle of Euglena and E. coli to streptomycin
originates from change during the 16S rRNA gathering. Tantamount results were found for the
restriction of Streptomyces to Spectinomycin. Anti-microbial prescription resistance appears to begin
from changes during the 30S rRNA.
In anoThe job of tRNA is to read the message of nucleic acids, or nucleotides, and translate it into
proteins, or amino acids. The process of making a protein from an mRNA template is called translation.
How does tRNA read the mRNA? It reads the mRNA in three-letter nucleotide sequences called codons. Each
individual codon corresponds to an amino acid. There are four nucleotides in mRNA. If you do the math to
figure out how many different codons exist, you arrive at 64, or four cubed (4^3). There is one tRNA molecule
for each codon.
Interestingly, there are only 21 amino acids. This brings up the idea that our genetic code is redundant. That is,
we have 64 codons but only 21 amino acids. How do we resolve this? More than one codon can specify for an
amino acid.
each codon has only one corresponding amino acid. Thus, we say that the genetic code is redundant, but not
ambiguous. For example, the codons GUU, GUC, GUA, and GUG all code for Valine (redundancy), and none
of them specify any other amino acid (no ambiguity).
11. So, we now know that the job of tRNA is to bring an amino acid to the ribosome. We also know that each
codon has its own tRNA and that each tRNA has its own amino acid attached to it. Further, we know that the
job of tRNA is to transport amino acids to the ribosome for protein production.
The tRNA doesn't become part of the protein which suggests that tRNA can either be attached to an amino acid
or free. We call this charged or uncharged.
In below image you will see structure and functioning of tRna:
Small nuclear RNA:
Small RNAs play a major role in the post-transcriptional regulation of gene expression. Though RNA was
initially discovered in nematodes and plants,
RNA-mediated regulation is widely found in eukaryotic organisms, and similar small RNA guided regulatory
pathways appear to be operative in prokaryotes.
Eukaryotic small RNAs play critical roles in regulating gene expression in development, cancer biology, anti-
viral defense and chromatin modification.
Researchers have capitalized on regulatory pathways mediated by small RNAs to enable analyses of gene
function not previously possible.
Below you will see the model function of sRNA.
12. Guide RNA:
It involved in processing of RNA or DNA in some organisms.
In kinetoplast Trypanosomes guide RNAs (gRNAs) direct the insertion and or deletion of uridylates in
mitochondrial mRNA. gRNA directed mRNA editing is necessary for the maturation and proper function of
12 out of 18 mitochondrial protein encoding mRNAs
Not surprisingly, proper gRNA function is essential for full completion of the Trypanosome life cycle, as
organisms that have impaired or absent gRNA function do not survive past the procyclic or insect stage of
development
Guide RNA directed editing normally is thought to correct frameshift errors present in the gene sequence
present in the mitochondrial genome as originally described by Benne. Editing of the cytochrome b gene,
however, results not in a frameshift but the generation of a start codon demonstrating that gRNA directed
editing can correct multiple types of genomic sequence errors.
Additionally, several recent studies have demonstrated that guide RNA directed editing might be a
mechanism by which Trypanosomes may regulate the functional diversity of their protein encoding genes.
Recently it was shown that alternate editing of the coxIII gene leads to a novel function of this gene. This
report has led to the speculation that guide RNA directed editing in trypanosomes like alternate splicing in
eukaryotes may be a mechanism to encode for protein diversity and evolutionary adaptation.
13. Antisense RNAs
Antisense RNAs are used to bind to complementary mRNAs and inhibit protein translation. Antisense RNAs
are single stranded RNAs that can be utilized as a laboratory technique to inhibit protein translation. Antisense
RNAs have also been found to be naturally occurring in bacteria such as E. coli with the R1 plasmid. The
antisense RNAs are categorized as small regulatory RNAs due to their small size. They can be divided into
either cis- or trans-antisense RNAs. Cis-antisense RNAs are encoded by an overlap between the antisense RNA
itself and the target gene. In trans-antisense RNAs, the antisense RNA gene is separate from the target gene and
there is no overlap.
this image displays a mechanism of antisense DNA.
However, it is important to note that an antisense RNA functions in the same manner. The antisense RNA can
bind to the mRNA and inhibit translation. In some cases, small regulatory RNAs, not included in the antisense
category, can activate translation as well.
Small Regulatory RNAs
Small regulatory RNAs are non-coding RNA molecules that play a role in cellular processes such as activation
or inhibition processes.
These small regulatory RNAs play a critical role in gene regulation via numerous mechanisms.
The mechanisms by which small regulatory RNAs function include binding to protein targets, protein
modification, binding to mRNA targets, and regulating gene expression.
There are numerous classes of small regulatory RNAs that play a key role in regulation.
House-keeping RNAs
Small regulatory RNAs encompass many RNAs involved in house-keeping processes as well.
House-keeping genes are specific genes that function in maintaining basic cellular processes and a state of
homeostasis.
House-keeping RNAs identified to date include rRNA and tRNAs.
rRNAs that are house-keeping genes can bind to RNA polymerases and regulate transcription or function in
larger complexes that are required for protein secretion or synthesis processes.
14. References:
RNA: The Versatile Molecule". University of Utah. 2015.
Nucleotides and Nucleic Acids" (PDF). University of California, Los Angeles. Archived from the original (PDF) on
2015-09-23. Retrieved 2015-08-26.
Shukla RN (2014). Analysis of Chromosomes. ISBN 978-93-84568-17-7.
Jump up to:a b c Berg JM, Tymoczko JL, Stryer L (2002). Biochemistry (5th ed.). WH Freeman and Company. pp.
118–19, 781–808. ISBN 978-0-7167-4684-3. OCLC 179705944.
Tinoco I, Bustamante C (October 1999). "How RNA folds". Journal of Molecular Biology. 293 (2): 271–81.
doi:10.1006/jmbi.1999.3001. PMID 10550208.
Jump up to:a b Lee JC, Gutell RR (December 2004). "Diversity of base-pair conformations and their occurrence in
rRNA structure and RNA structural motifs". Journal of Molecular Biology. 344(5): 1225–49.
doi:10.1016/j.jmb.2004.09.072. PMID 15561141.
Barciszewski J, Frederic B, Clark C (1999). RNA biochemistry and biotechnology. Springer. pp. 73–87. ISBN 978-
0-7923-5862-6. OCLC 52403776.
Nowak R. Mining treasures from ‘junk DNA’ Science. 1994; 263:608–10. doi: 10.1126/science.7508142.
Gottesman S, Storz G. Bacterial small RNA regulators: versatile roles and rapidly evolving variations. Cold Spring
Harb Perspect Biol. 2011; 3:1–16. doi: 10.1101/cshperspect. A003798
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