RNA- A polymer of ribonucleotides, is a single stranded structure. There are three major types of RNA- m RNA,t RNA and r RNA. Besides that there are small nuclear,micro RNAs, small interfering and heterogeneous RNAs. Each of them has a specific structure and performs a specific function.
it describes transcription with simple diagram and animation. its steps and inhibitors are described for both eukaryotes and prokaryotes. it will be easily understood by UG students . post transcriptional modification of all the RNA are also described with diagrams.
RNA- A polymer of ribonucleotides, is a single stranded structure. There are three major types of RNA- m RNA,t RNA and r RNA. Besides that there are small nuclear,micro RNAs, small interfering and heterogeneous RNAs. Each of them has a specific structure and performs a specific function.
it describes transcription with simple diagram and animation. its steps and inhibitors are described for both eukaryotes and prokaryotes. it will be easily understood by UG students . post transcriptional modification of all the RNA are also described with diagrams.
DNA- Transcription and Tranlation, RNA, Ribosomes and membrane proteins.pptxLaibaSaher
Detailed presentation on the topic of DNA, transcription and translation, RNA, Ribosomes and Membrane proteins. Along with their structure and functions. Detailed Diagram and complete description of the processes. Along with references and Gifs that makes the presentation look more creative.
Provide an in depth description of biological information transfer (.pdfMALASADHNANI
Provide an in depth description of biological information transfer (what is the chemistry
underlying each information transfer event, which nucleotide sequences are involved etc.)
Solution
The genetic information is stored in Deoxyribonucleic acid,DNA. DNA contains the information
needed to build an individual. Genetic information is transferred from DNA and converted to
protein.RNA molecules work as messengers.Proteins are the biological workers.Information of
the DNA is copied to a RNA molecule in transcription.RNA directs the protein synthesis in a
translation.Protein’s 3D structure determines it’s function.Information transfer only in one
direction.
The biological information flows from DNA to RNA,and from there to proteins.It is ultimately
the DNA that controls every function of the cell through protein synthesis.As a carrier of genetic
information,DNA in a cell must be duplicated (replicated),maintained and passed dawn
accurately to the daughter cells.
DNA is deoxyribonucleic acid,which is found in chromosomes, contains inherited
information,they are made up of nucleotides,and are what make up genes. A nucleotide is
composed of a sugar (deoxyribose),a phosphate group,and a base.There are 4 bases found in
DNA, Adenine (A),Thymine (T),Guanine (G),and Cytosine (C).Adenine and guanine are double
ring bases while thymine and cytosine are single ring bases.Nucleotides are joined to each other
by covalent bonds between the phosphate group of one nucleotide and the 3\' carbon atom of the
deoxyribose (sugar) of the next nucleotide.Each DNA molecule is unique because the order of
nucleotides is unique. The order of nucleotides determines the order of amino acids in a
protein.RNA is a nucleic acid composed of nucleotides and consists of one strand of
nucleotides.There are three different types of RNA- Ribosomal,Messenger,and
Transfer.Ribosomal RNA is the RNA molecules found in ribosomes. The large subunit RNA
contains the enzymatic activity that makes the peptide bonds between amino acids. Messenger
RNA is what controls the order of amino acids in a protein and determines which gene it codes
for.Transfer RNA brings amino acids to ribosomes.The transfer RNA has two recognition sites-
one recognizes an amino acid and the other recognizes one codon.The transfer RNA brings the
the correct amino acid to the ribosome.
Transcription is the process by which the information contained in a section of DNA is replicated
in the form of a newly assembled piece of messenger RNA (mRNA).Enzymes facilitating the
process include RNA polymerase and transcription factors.In eukaryotic cells the primary
transcript is pre-mRNA. Pre-mRNA must be processed for translation to proceed.Processing
includes the addition of a 5\' cap and a poly-A tail to the pre-mRNA chain,followed by
splicing.Alternative splicing occurs when appropriate, increasing the diversity of the proteins
that any single mRNA can produce.The product of the entire transcription process is a mature
mRNA ch.
• Define transcription• Define translation• What are the 3 steps.pdfarihantelehyb
• Define transcription
• Define translation
• What are the 3 steps of translation?
• Define the “genetic dogma”
• What is the function of Transfer RNA?
• What is the function of RNA polymerase?
• What is the function of DNA polymerase?
• Define “splicing of RNA”
• What is an exon?
• What component of the cell does the translation?
• What molecule in the cell does transcription?
• What are the functions of: operon, promotor?
• What is the difference between inducible operon and repressible operon?
Solution
• Define transcription
Transcription is the process of making an RNA copy of a gene sequence. This copy, called a
messenger RNA (mRNA) molecule, leaves the cell nucleus and enters the cytoplasm, where it
directs the synthesis of the protein, which it encodes. Here is a more complete definition of
transcription.
• Define translation
Translation is the process of translating the sequence of a messenger RNA (mRNA) molecule to
a sequence of amino acids during protein synthesis. The genetic code describes the relationship
between the sequence of base pairs in a gene and the corresponding amino acid sequence that it
encodes. In the cell cytoplasm, the ribosome reads the sequence of the mRNA in groups of three
bases to assemble the protein. Here is a more complete definition of translation:
• What are the 3 steps of translation?
Step # 1. Initiation:
Initiation of translation in E .coli involves the small ribosome subunit, a mRNA molecule, a
specific charge initiator tRNA, GTP, Mg++ and number of proteinaceous initiation factors (IFs).
These are initially part of the small subunit and are required to enhance binding affinity of the
various translational components (Table 8.1). Unlike ribosomal proteins, IFs are released from
the ribosome once initiation is completed.
Step # 2. Elongation:
Once both subunits of the ribosome are assembled with the mRNA, binding site for two charged
tRNA molecules are formed. These are designated as the ‘P’ or peptidyl and the ‘A’ or
aminoacyl sites. The charged initiator tRNA binds to the P site, provided that the AUG triplet of
mRNA is in the corresponding position of the small subunit. The increase of the growing
polypeptide chain by one amino acid is called elongation.
Step # 3. Termination:
Termination of protein synthesis is carried out by triplet codes (UAG, UAA, UGA; stop codons)
present at site A. These codons do not specify an amino acid, nor do they call for a tRNA in the
A site. These codons are called stop codons, termination codons or nonsense codons. The
finished polypeptide is still attached to the terminal tRNA at the P site, and the A site is empty.
• Define the “genetic dogma”
A theory in genetics and molecular biology subject to several exceptions that genetic information
is coded in self-replicating DNA and undergoes unidirectional transfer to messenger RNAs in
transcription which act as templates for protein synthesis in translation
• What is the function of Transfer RNA?
The tRNA molecule, or tr.
Types and functions of RNA. Of the many types of RNA, the three most well-known and most commonly studied are messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA),
This presentation explores a brief idea about the structural and functional attributes of nucleotides, the structure and function of genetic materials along with the impact of UV rays and pH upon them.
What is greenhouse gasses and how many gasses are there to affect the Earth.moosaasad1975
What are greenhouse gasses how they affect the earth and its environment what is the future of the environment and earth how the weather and the climate effects.
Richard's entangled aventures in wonderlandRichard Gill
Since the loophole-free Bell experiments of 2020 and the Nobel prizes in physics of 2022, critics of Bell's work have retreated to the fortress of super-determinism. Now, super-determinism is a derogatory word - it just means "determinism". Palmer, Hance and Hossenfelder argue that quantum mechanics and determinism are not incompatible, using a sophisticated mathematical construction based on a subtle thinning of allowed states and measurements in quantum mechanics, such that what is left appears to make Bell's argument fail, without altering the empirical predictions of quantum mechanics. I think however that it is a smoke screen, and the slogan "lost in math" comes to my mind. I will discuss some other recent disproofs of Bell's theorem using the language of causality based on causal graphs. Causal thinking is also central to law and justice. I will mention surprising connections to my work on serial killer nurse cases, in particular the Dutch case of Lucia de Berk and the current UK case of Lucy Letby.
Multi-source connectivity as the driver of solar wind variability in the heli...Sérgio Sacani
The ambient solar wind that flls the heliosphere originates from multiple
sources in the solar corona and is highly structured. It is often described
as high-speed, relatively homogeneous, plasma streams from coronal
holes and slow-speed, highly variable, streams whose source regions are
under debate. A key goal of ESA/NASA’s Solar Orbiter mission is to identify
solar wind sources and understand what drives the complexity seen in the
heliosphere. By combining magnetic feld modelling and spectroscopic
techniques with high-resolution observations and measurements, we show
that the solar wind variability detected in situ by Solar Orbiter in March
2022 is driven by spatio-temporal changes in the magnetic connectivity to
multiple sources in the solar atmosphere. The magnetic feld footpoints
connected to the spacecraft moved from the boundaries of a coronal hole
to one active region (12961) and then across to another region (12957). This
is refected in the in situ measurements, which show the transition from fast
to highly Alfvénic then to slow solar wind that is disrupted by the arrival of
a coronal mass ejection. Our results describe solar wind variability at 0.5 au
but are applicable to near-Earth observatories.
Seminar of U.V. Spectroscopy by SAMIR PANDASAMIR PANDA
Spectroscopy is a branch of science dealing the study of interaction of electromagnetic radiation with matter.
Ultraviolet-visible spectroscopy refers to absorption spectroscopy or reflect spectroscopy in the UV-VIS spectral region.
Ultraviolet-visible spectroscopy is an analytical method that can measure the amount of light received by the analyte.
THE IMPORTANCE OF MARTIAN ATMOSPHERE SAMPLE RETURN.Sérgio Sacani
The return of a sample of near-surface atmosphere from Mars would facilitate answers to several first-order science questions surrounding the formation and evolution of the planet. One of the important aspects of terrestrial planet formation in general is the role that primary atmospheres played in influencing the chemistry and structure of the planets and their antecedents. Studies of the martian atmosphere can be used to investigate the role of a primary atmosphere in its history. Atmosphere samples would also inform our understanding of the near-surface chemistry of the planet, and ultimately the prospects for life. High-precision isotopic analyses of constituent gases are needed to address these questions, requiring that the analyses are made on returned samples rather than in situ.
A brief information about the SCOP protein database used in bioinformatics.
The Structural Classification of Proteins (SCOP) database is a comprehensive and authoritative resource for the structural and evolutionary relationships of proteins. It provides a detailed and curated classification of protein structures, grouping them into families, superfamilies, and folds based on their structural and sequence similarities.
Introduction:
RNA interference (RNAi) or Post-Transcriptional Gene Silencing (PTGS) is an important biological process for modulating eukaryotic gene expression.
It is highly conserved process of posttranscriptional gene silencing by which double stranded RNA (dsRNA) causes sequence-specific degradation of mRNA sequences.
dsRNA-induced gene silencing (RNAi) is reported in a wide range of eukaryotes ranging from worms, insects, mammals and plants.
This process mediates resistance to both endogenous parasitic and exogenous pathogenic nucleic acids, and regulates the expression of protein-coding genes.
What are small ncRNAs?
micro RNA (miRNA)
short interfering RNA (siRNA)
Properties of small non-coding RNA:
Involved in silencing mRNA transcripts.
Called “small” because they are usually only about 21-24 nucleotides long.
Synthesized by first cutting up longer precursor sequences (like the 61nt one that Lee discovered).
Silence an mRNA by base pairing with some sequence on the mRNA.
Discovery of siRNA?
The first small RNA:
In 1993 Rosalind Lee (Victor Ambros lab) was studying a non- coding gene in C. elegans, lin-4, that was involved in silencing of another gene, lin-14, at the appropriate time in the
development of the worm C. elegans.
Two small transcripts of lin-4 (22nt and 61nt) were found to be complementary to a sequence in the 3' UTR of lin-14.
Because lin-4 encoded no protein, she deduced that it must be these transcripts that are causing the silencing by RNA-RNA interactions.
Types of RNAi ( non coding RNA)
MiRNA
Length (23-25 nt)
Trans acting
Binds with target MRNA in mismatch
Translation inhibition
Si RNA
Length 21 nt.
Cis acting
Bind with target Mrna in perfect complementary sequence
Piwi-RNA
Length ; 25 to 36 nt.
Expressed in Germ Cells
Regulates trnasposomes activity
MECHANISM OF RNAI:
First the double-stranded RNA teams up with a protein complex named Dicer, which cuts the long RNA into short pieces.
Then another protein complex called RISC (RNA-induced silencing complex) discards one of the two RNA strands.
The RISC-docked, single-stranded RNA then pairs with the homologous mRNA and destroys it.
THE RISC COMPLEX:
RISC is large(>500kD) RNA multi- protein Binding complex which triggers MRNA degradation in response to MRNA
Unwinding of double stranded Si RNA by ATP independent Helicase
Active component of RISC is Ago proteins( ENDONUCLEASE) which cleave target MRNA.
DICER: endonuclease (RNase Family III)
Argonaute: Central Component of the RNA-Induced Silencing Complex (RISC)
One strand of the dsRNA produced by Dicer is retained in the RISC complex in association with Argonaute
ARGONAUTE PROTEIN :
1.PAZ(PIWI/Argonaute/ Zwille)- Recognition of target MRNA
2.PIWI (p-element induced wimpy Testis)- breaks Phosphodiester bond of mRNA.)RNAse H activity.
MiRNA:
The Double-stranded RNAs are naturally produced in eukaryotic cells during development, and they have a key role in regulating gene expression .
1. Typesof RNA
Niloufer M.A and Dr. Kayeen Vadakkan
Department of Biotechnology
ST.MARY’S COLLEGE, THRISSUR
2. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
INTODUCTION
RNA or ribonucleic acid is a polymer of nucleotides that is
made up of a ribose sugar, a phosphate, and bases such as
adenine, guanine, cytosine, and uracil.
It plays a crucial role in gene expression by acting as the
intermediate between the genetic information encoded by
DNA and proteins.
RNA has a structure very similar to that of DNA. The key
difference in RNA structure is that the ribose sugar in RNA
possesses a hydroxyl (-OH) group that is absent in DNA.
3. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
4. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
MessengerRNA (mRNA)
Messenger ribonucleic acids (mRNAs) transfer the
information from DNA to the cell machinery that makes
proteins.
mRNA accounts for just 5% of the total RNA in the cell.
mRNA is the most heterogeneous of the 3 types of RNA in
terms of both base sequence and size.
It carries complimentary genetic code copied, from DNA during
transcription, in the form of triplets of nucleotides called codons.
The message of mRNA is read consecutively in 5’3’ direction.
5. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
Molecules of mRNA are composed of relatively short, single
strands of molecules made up of adenine, cytosine, guanine
and uracil bases held together by a sugar phosphate
backbone.
When RNA polymerase finishes reading a section of the
DNA, the pre-mRNA copy is processed to form mature mRNA
and then transferred out of the cell nucleus.
Ribosomes read the mRNA and translate the message into
functional proteins in a process called translation.
6. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
Depending on the newly synthesized protein’s structure
and function, it will be further modified by the cell, exported
to the extra-cellular space, or will remain inside the cell.
Precursor mRNA contains introns and exons. Introns are
removed before translation, while exons code for the amino
acid sequence of proteins.
To make mature mRNA, the cell machinery removes
“non-translatable” introns from the pre-mRNA, leaving only
translatable exon sequences in the mRNA.
7. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
8. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
Types of mRNA
Pre-mRNA and hnRNA
•Precursor mRNA (pre-mRNA) is the primary transcript of
eukaryotic mRNA as it comes off the DNA template.
• Pre-mRNA is part of a group of RNAs called heterogeneous
nuclear RNA (hnRNA).
• hnRNA refers to all single strand RNA located inside the nucleus
of the cell where transcription takes place (DNA->RNA) and pre-
mRNA form a large part of these ribonucleic acids.
9. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
• Pre-mRNA contains sequences that need to be removed or
“spliced out” before being translated into a protein.
•These sequences can either be removed through the catalytic
activity of the RNA itself, or through the action of a multi-
protein structure called spliceosome.
•After this processing step, the pre-mRNA is considered as a
mature mRNA transcript.
Monocistronic mRNA
A monocistronic mRNA molecule contains the exon
sequences coding for a single protein. Most eukaryotic
mRNAs are monocistronic.
10. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
Bicistronic mRNA
A bicistronic mRNA molecule contains the exon coding
sequences for two proteins.
Polycistronic mRNA
A polycistronic mRNA molecule contains the exon coding
sequences for multiple proteins. Most mRNA
of bacteria and bacteriophages (viruses that live in bacterial
hosts) are polycistronic.
11. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
Ribosomal RNA (rRNA)
rRNAs are found in the ribosomes and account for 80% of the total
RNA present in the cell.
Ribosomes are composed of a large subunit called the 50S and a
small subunit called the 30S, each of which is made up of its own
specific rRNA molecules.
Different rRNAs present in the ribosomes include small rRNAs and
large rRNAs, which belong to the small and large subunits of the
ribosome, respectively.
12. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
13. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
rRNAs combine with proteins and enzymes in the cytoplasm
to form ribosomes, which act as the site of protein synthesis.
These complex structures travel along the mRNA molecule
during translation and facilitate the assembly of amino acids to
form a polypeptide chain.
They interact with tRNAs and other molecules that are crucial
to protein synthesis.
In bacteria, the small and large rRNAs contain about 1500 and
3000 nucleotides, respectively, whereas in humans, they have
about 1800 and 5000 nucleotides, respectively.
14. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
Transfer RNA (tRNA)
tRNA is the smallest of the 3 types of RNA, possessing
around 75-95 nucleotides.
tRNAs are an essential component of translation, where
their main function is the transfer of amino acids during
protein synthesis. Therefore, they are called transfer RNAs.
tRNAs also act as adapters in the translation of the genetic
sequence of mRNA into proteins. Thus, they are also called
adapter molecules.
15. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
16. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
tRNAs have a clover leaf structure which is stabilized by
strong hydrogen bonds between the nucleotides.
They normally contain some unusual bases in addition to
the usual 4, which are formed by methylation of the usual
bases.
Methyl guanine and methylcytosine are two examples of
methylated bases.
Each of the 20 amino acids has a specific tRNA that binds
with it and transfers it to the growing polypeptide chain.
17. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR
18. TYPES OF RNA, NILOUFER M.A, ST.MAR’YS COLLEGE - THRISSUR