The document provides an overview of DNA structure and function, including:
- DNA is a double-helix structure with bases pairing between strands.
- DNA replication is semiconservative and involves unwinding of the strands followed by synthesis of new strands using the old strands as templates.
- Gene expression involves two main steps - transcription of DNA to mRNA in the nucleus, and translation of mRNA to proteins in the cytoplasm using transfer RNA and ribosomes.
- Gene expression is regulated at multiple levels including chromatin structure, transcription factors, RNA processing, and mRNA translation controls.
The document discusses DNA, RNA, and protein synthesis. It describes key discoveries such as the Hershey-Chase experiment demonstrating that DNA is the genetic material. It explains the structure of DNA as a double helix with base pairing between strands. The process of DNA replication is summarized, including semi-conservative replication and the role of enzymes. Transcription of DNA to RNA and translation of RNA to protein are also summarized, with an overview of the central dogma of molecular biology.
The document discusses the process by which genes are transcribed into mRNA and then translated into proteins. It explains that DNA is transcribed into mRNA, which is then translated on ribosomes into amino acid chains that fold into functional proteins. The genetic code is explained, where triplets of nucleotides in mRNA (codons) encode for specific amino acids. The nearly universal nature of the genetic code is also covered.
This document summarizes key discoveries and scientists involved in understanding DNA and genetics. It describes Frederick Griffith's experiments in 1928 which showed bacteria could undergo transformation through incorporation of DNA from other bacteria. Later experiments by Avery, MacLeod and McCarty in 1944 confirmed DNA was the transforming agent. The document then outlines discoveries around DNA structure including its double helix shape discovered by Watson and Crick in 1953 based on X-ray crystallography data from Rosalind Franklin. It also summarizes DNA replication and basic concepts in genetics like transcription, translation and genetic code.
DNA is a double helical structure that transfers the genetic information from one generation to another. it consists of two strands with the four nucleotide basis .The four nucleotides contains adenine, cytosine, guanine, thymine .These four nuclic basis are such arranged and coiled with the help of hydrogen bonds and forms the helical structure of DNA. In RNA the thymine is replaced with uracil. Here you will learn the replication ,transcription and translation process in DNA.
1. Experiments by Griffith, Avery, MacLeod, and McCarty provided evidence that DNA is the genetic material, carrying hereditary information from parents to offspring.
2. Watson and Crick discovered that DNA has a double helix structure, with nucleotides containing complementary bases (A-T and G-C) that bond the two strands together.
3. The double helix structure explained how DNA can replicate precisely by unwinding and each strand serving as a template for a new complementary strand.
Caesar's wife Agrippina poisoned him by mixing poisonous Amanita caesarea mushrooms into his favorite mushroom dish, as these mushrooms contain a substance that blocks the enzyme needed for cells to transcribe mRNA from DNA, leading to liver failure and death for Caesar two days later. DNA holds the genetic instructions for cells and is replicated before cell division so each new cell has a copy, while RNA carries copies of the DNA instructions out of the nucleus to direct protein production through transcription and translation.
DNA replication, transcription, and translationjun de la Ceruz
The document provides information about DNA, RNA, transcription, and translation. It defines the key components and structures of DNA and RNA, including sugars, phosphates, and nitrogenous bases. It explains the differences between DNA and RNA, such as DNA being double-stranded and containing deoxyribose and thymine, while RNA is single-stranded and contains ribose and uracil. The document also describes transcription, which occurs in the nucleus and produces mRNA from DNA, and translation, which occurs in the cytoplasm and uses mRNA to produce a polypeptide chain through the actions of tRNA and the ribosome.
DNA carries genetic information from one generation to the next and must replicate itself accurately when cells divide. DNA replication occurs via a semi-conservative process where each new DNA strand contains one original strand and one newly synthesized strand. During transcription, mRNA is synthesized from a gene on DNA using one DNA strand as a template. Translation then builds a polypeptide chain from the mRNA codon sequence using tRNA to add amino acids specified by each codon. Molecular recognition allows for specific interactions between proteins and other molecules through complementary binding of receptors, antigens, enzymes and substrates.
The document discusses DNA, RNA, and protein synthesis. It describes key discoveries such as the Hershey-Chase experiment demonstrating that DNA is the genetic material. It explains the structure of DNA as a double helix with base pairing between strands. The process of DNA replication is summarized, including semi-conservative replication and the role of enzymes. Transcription of DNA to RNA and translation of RNA to protein are also summarized, with an overview of the central dogma of molecular biology.
The document discusses the process by which genes are transcribed into mRNA and then translated into proteins. It explains that DNA is transcribed into mRNA, which is then translated on ribosomes into amino acid chains that fold into functional proteins. The genetic code is explained, where triplets of nucleotides in mRNA (codons) encode for specific amino acids. The nearly universal nature of the genetic code is also covered.
This document summarizes key discoveries and scientists involved in understanding DNA and genetics. It describes Frederick Griffith's experiments in 1928 which showed bacteria could undergo transformation through incorporation of DNA from other bacteria. Later experiments by Avery, MacLeod and McCarty in 1944 confirmed DNA was the transforming agent. The document then outlines discoveries around DNA structure including its double helix shape discovered by Watson and Crick in 1953 based on X-ray crystallography data from Rosalind Franklin. It also summarizes DNA replication and basic concepts in genetics like transcription, translation and genetic code.
DNA is a double helical structure that transfers the genetic information from one generation to another. it consists of two strands with the four nucleotide basis .The four nucleotides contains adenine, cytosine, guanine, thymine .These four nuclic basis are such arranged and coiled with the help of hydrogen bonds and forms the helical structure of DNA. In RNA the thymine is replaced with uracil. Here you will learn the replication ,transcription and translation process in DNA.
1. Experiments by Griffith, Avery, MacLeod, and McCarty provided evidence that DNA is the genetic material, carrying hereditary information from parents to offspring.
2. Watson and Crick discovered that DNA has a double helix structure, with nucleotides containing complementary bases (A-T and G-C) that bond the two strands together.
3. The double helix structure explained how DNA can replicate precisely by unwinding and each strand serving as a template for a new complementary strand.
Caesar's wife Agrippina poisoned him by mixing poisonous Amanita caesarea mushrooms into his favorite mushroom dish, as these mushrooms contain a substance that blocks the enzyme needed for cells to transcribe mRNA from DNA, leading to liver failure and death for Caesar two days later. DNA holds the genetic instructions for cells and is replicated before cell division so each new cell has a copy, while RNA carries copies of the DNA instructions out of the nucleus to direct protein production through transcription and translation.
DNA replication, transcription, and translationjun de la Ceruz
The document provides information about DNA, RNA, transcription, and translation. It defines the key components and structures of DNA and RNA, including sugars, phosphates, and nitrogenous bases. It explains the differences between DNA and RNA, such as DNA being double-stranded and containing deoxyribose and thymine, while RNA is single-stranded and contains ribose and uracil. The document also describes transcription, which occurs in the nucleus and produces mRNA from DNA, and translation, which occurs in the cytoplasm and uses mRNA to produce a polypeptide chain through the actions of tRNA and the ribosome.
DNA carries genetic information from one generation to the next and must replicate itself accurately when cells divide. DNA replication occurs via a semi-conservative process where each new DNA strand contains one original strand and one newly synthesized strand. During transcription, mRNA is synthesized from a gene on DNA using one DNA strand as a template. Translation then builds a polypeptide chain from the mRNA codon sequence using tRNA to add amino acids specified by each codon. Molecular recognition allows for specific interactions between proteins and other molecules through complementary binding of receptors, antigens, enzymes and substrates.
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.
This document provides an overview of protein synthesis, including:
1. It describes the process of transcription, where information from DNA is transcribed into mRNA in the nucleus.
2. Translation, or protein synthesis, then occurs in the cytoplasm, where the mRNA sequence is read by ribosomes to produce a polypeptide chain based on the genetic code.
3. Protein synthesis involves initiation, elongation through the addition of amino acids guided by tRNAs, and termination when a stop codon is reached.
Transcription is the process of making mRNA from DNA. It involves RNA polymerase making an mRNA complementary copy of the DNA strand. Translation is the process of using the mRNA to produce a polypeptide by linking amino acids specified by the mRNA codons. During transcription, introns are removed from pre-mRNA and exons are joined to form mature mRNA. If the parent DNA strand is A A T G C A G T, the complementary mRNA strand will be U U A C G U C A.
DNA structure replication transcription translationAman Ullah
DNA is made up of four nucleotides that form a double helix structure. Watson and Crick discovered that DNA replicates in a semi-conservative manner, with each new DNA molecule composed of one original strand and one newly synthesized strand. DNA replication is highly regulated and involves several enzymes that unwind, proofread, and repair the DNA to replicate it with high fidelity. The information stored in DNA is used to direct the synthesis of proteins according to the central dogma of biology, with DNA being transcribed into RNA which is then translated into proteins.
DNA and RNA differ in their chemical structures. While DNA is double-stranded, RNA is single-stranded. There are four main types of RNA - messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and small stable RNA. mRNA carries genetic information from DNA to the ribosome. It is modified with a 5' cap and 3' poly-A tail. tRNA transfers amino acids to the growing polypeptide chain during protein synthesis. rRNA makes up the ribosomal subunits and is involved in protein synthesis.
DNA and RNA have similar structures but differ in key ways. DNA contains deoxyribose and is usually double stranded, carrying genetic information in cells as DNA. Its classic double helix structure contains paired bases (A-T and C-G) connected by hydrogen bonds. RNA is usually single stranded and contains ribose. There are three main types of RNA - mRNA, tRNA, and rRNA - that have different roles like transcribing DNA instructions and transporting amino acids for protein synthesis. tRNA and other RNAs fold into cloverleaf secondary structures stabilized by hydrogen bonding within their nucleotide sequences.
The slide presenting the Importance of genetic code and discusses how does the genetic code deduced that brings in the entire understanding of Genetic today.
Lecture on DNA to Proteins (The Central Dogma of Molecular Biology)Marilen Parungao
- Transcription must occur before translation. Transcription involves copying DNA into mRNA, which is then used as a template for translation.
- The LAC operon is activated under conditions where glucose is low/lactose is high. It is inactivated when glucose is high/lactose is low.
- The DNA sequence provided would be transcribed into an RNA sequence where all Ts would be replaced with Us: 3'-UAC GGC AUU GCA CAU UUU AGG GGC AAU AUU-5'
The document describes the central dogma of molecular biology:
DNA is transcribed into RNA, which is then translated into proteins. DNA contains the genetic code in nucleotides that make up genes. RNA polymerase transcribes DNA into messenger RNA (mRNA) in the nucleus. mRNA is then translated by ribosomes in the cytoplasm into proteins based on the RNA code using transfer RNA (tRNA) and amino acids. The process of protein synthesis involves transcription of DNA to mRNA and then translation of mRNA to proteins.
1. DNA replication is semi-conservative. Helicase unwinds the DNA double helix, DNA polymerase links nucleotides to form new strands using the existing strands as templates.
2. Transcription creates mRNA from DNA templates using RNA polymerase.
3. Translation uses the genetic code to synthesize polypeptides from mRNA. tRNAs with anticodons complementary to mRNA codons carry amino acids which are linked by the ribosome.
1. DNA contains the genetic code and instructions for making proteins, which it stores in the cell nucleus. 2. During transcription, RNA polymerase copies DNA into messenger RNA (mRNA) which carries the code to the cytoplasm. 3. In translation, ribosomes use mRNA to produce proteins according to the genetic code by linking amino acids specified by mRNA codons. 4. Newly formed proteins travel to the endoplasmic reticulum and Golgi body for processing and packaging before use in the cell.
This document discusses the phenomenon of ab initio DNA synthesis, where DNA polymerases can synthesize new DNA strands without a template. It provides a history of the discovery of this process and studies showing DNA polymerases can generate short repetitive sequences on their own. The document also explores how adding other enzymes like restriction endonucleases, nicking endonucleases and helicase can stimulate ab initio DNA synthesis. Finally, it proposes models for how this template-independent DNA synthesis may occur and discusses potential functional roles and implications.
The document provides information on the structure of DNA and RNA. It discusses how DNA was discovered to have a double helix structure by Watson and Crick in 1953 based on prior work by scientists like Franklin, Wilkins, Chargaff and Pauling. It describes the key components of DNA including the sugar-phosphate backbone, nitrogenous bases, and how the bases pair up in the double helix structure. It also discusses different DNA structures like A, B and Z-DNA and how DNA packages into nucleosomes and chromosomes. For RNA, it notes that it is similar to DNA but contains the sugar ribose and base uracil instead of thymine.
1. DNA contains genetic instructions that can be copied and passed from generation to generation. It is made up of nucleotides with four bases that form base pairs to create a double helix structure.
2. DNA replication is the process where the DNA double helix unwinds and each strand serves as a template to make a new complementary strand, duplicating the DNA within the cell.
3. Genetic information flows from DNA to RNA to protein. Through transcription, DNA is used as a template to make messenger RNA (mRNA), which carries the genetic code to be translated by ribosomes into proteins.
DNA contains the genetic material of organisms in the form of nucleotides arranged in a double helix structure. The double helix is composed of two strands of nucleotides linked by hydrogen bonds between complementary nucleotide bases. DNA stores and transmits genetic information from one generation to the next through replication and cell division. It controls the development of an organism's phenotype through gene expression and can produce variations through mutation that lead to evolution over time.
RNA and protein synthesis involves two main steps: transcription and translation. During transcription, DNA is used as a template to produce mRNA through the enzymatic action of RNA polymerase. The mRNA then leaves the nucleus and binds to ribosomes for translation. During translation, tRNA brings amino acids to the ribosome according to the mRNA codon sequence. The amino acids are linked together to form a polypeptide or protein chain. Translation stops when a stop codon is reached.
Nucleic acids are macromolecules that store genetic information and provide instructions for building proteins. There are two main types: DNA and RNA. DNA contains the genetic blueprint in the form of a double-stranded structure located in the cell's nucleus. RNA is single-stranded and involved in protein synthesis. The central dogma of molecular biology describes how DNA is transcribed into RNA then translated into proteins. DNA replication is the process where DNA makes a copy of itself during cell division which involves unwinding of the DNA double helix, addition of nucleotides to form new strands, and production of two identical DNA molecules.
Replication, transcription, translation and its regulationAbhinava J V
This document summarizes key processes in DNA replication, transcription, translation, and their regulation in prokaryotes and eukaryotes. It describes how DNA makes copies of itself semiconservatively. Transcription involves RNA polymerase making an RNA copy of a DNA template. Translation uses ribosomes to convert the RNA into a polypeptide chain. Each process has initiation, elongation, and termination steps. Regulation ensures processes only occur at the right times and locations in the cell.
1. DNA (deoxyribonucleic acid) is a chemical found in the nuclei of living cells that controls chemical changes and determines cell and organism type.
2. DNA is a long molecule composed of nucleotides, each containing a sugar (deoxyribose), phosphate group, and organic base (adenine, thymine, cytosine, or guanine).
3. DNA replicates before cell division by unwinding its double helix structure and using each strand as a template to make a new partner strand, resulting in two identical DNA molecules for each daughter cell after division.
Dna replication, transcription and translationAshfaq Ahmad
DNA is made up of four nucleotides that form a double helix structure. Watson and Crick discovered that DNA replicates in a semi-conservative manner where each new DNA molecule contains one original and one new strand. DNA replication is highly regulated and involves several enzymes to ensure its accuracy and fidelity. Errors can occur but are typically corrected by DNA repair mechanisms. The information stored in DNA is used to make RNA and proteins through the central dogma of molecular biology which involves two key processes - transcription of DNA to RNA and translation of RNA to protein.
DNA contains the genetic code and is made up of nucleotides containing a sugar, phosphate, and one of four nitrogenous bases (A, T, C, G). DNA replicates via DNA polymerase which uses DNA as a template to produce new DNA strands. During transcription, RNA polymerase uses one DNA strand as a template to produce messenger RNA (mRNA), and during translation the mRNA directs the assembly of proteins from amino acids on ribosomes based on its codon sequence. Key enzymes and processes involved in DNA replication, transcription, and translation help copy genetic information and synthesize proteins.
The central dogma of biology describes the flow of genetic information: DNA is replicated to make more DNA; DNA is transcribed into mRNA; mRNA is translated into proteins. This involves three main molecules - DNA, RNA, and proteins - and three main processes - replication, transcription, and translation. The genetic code stored in DNA is used to direct the synthesis of proteins via mRNA and translation.
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.
This document provides an overview of protein synthesis, including:
1. It describes the process of transcription, where information from DNA is transcribed into mRNA in the nucleus.
2. Translation, or protein synthesis, then occurs in the cytoplasm, where the mRNA sequence is read by ribosomes to produce a polypeptide chain based on the genetic code.
3. Protein synthesis involves initiation, elongation through the addition of amino acids guided by tRNAs, and termination when a stop codon is reached.
Transcription is the process of making mRNA from DNA. It involves RNA polymerase making an mRNA complementary copy of the DNA strand. Translation is the process of using the mRNA to produce a polypeptide by linking amino acids specified by the mRNA codons. During transcription, introns are removed from pre-mRNA and exons are joined to form mature mRNA. If the parent DNA strand is A A T G C A G T, the complementary mRNA strand will be U U A C G U C A.
DNA structure replication transcription translationAman Ullah
DNA is made up of four nucleotides that form a double helix structure. Watson and Crick discovered that DNA replicates in a semi-conservative manner, with each new DNA molecule composed of one original strand and one newly synthesized strand. DNA replication is highly regulated and involves several enzymes that unwind, proofread, and repair the DNA to replicate it with high fidelity. The information stored in DNA is used to direct the synthesis of proteins according to the central dogma of biology, with DNA being transcribed into RNA which is then translated into proteins.
DNA and RNA differ in their chemical structures. While DNA is double-stranded, RNA is single-stranded. There are four main types of RNA - messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and small stable RNA. mRNA carries genetic information from DNA to the ribosome. It is modified with a 5' cap and 3' poly-A tail. tRNA transfers amino acids to the growing polypeptide chain during protein synthesis. rRNA makes up the ribosomal subunits and is involved in protein synthesis.
DNA and RNA have similar structures but differ in key ways. DNA contains deoxyribose and is usually double stranded, carrying genetic information in cells as DNA. Its classic double helix structure contains paired bases (A-T and C-G) connected by hydrogen bonds. RNA is usually single stranded and contains ribose. There are three main types of RNA - mRNA, tRNA, and rRNA - that have different roles like transcribing DNA instructions and transporting amino acids for protein synthesis. tRNA and other RNAs fold into cloverleaf secondary structures stabilized by hydrogen bonding within their nucleotide sequences.
The slide presenting the Importance of genetic code and discusses how does the genetic code deduced that brings in the entire understanding of Genetic today.
Lecture on DNA to Proteins (The Central Dogma of Molecular Biology)Marilen Parungao
- Transcription must occur before translation. Transcription involves copying DNA into mRNA, which is then used as a template for translation.
- The LAC operon is activated under conditions where glucose is low/lactose is high. It is inactivated when glucose is high/lactose is low.
- The DNA sequence provided would be transcribed into an RNA sequence where all Ts would be replaced with Us: 3'-UAC GGC AUU GCA CAU UUU AGG GGC AAU AUU-5'
The document describes the central dogma of molecular biology:
DNA is transcribed into RNA, which is then translated into proteins. DNA contains the genetic code in nucleotides that make up genes. RNA polymerase transcribes DNA into messenger RNA (mRNA) in the nucleus. mRNA is then translated by ribosomes in the cytoplasm into proteins based on the RNA code using transfer RNA (tRNA) and amino acids. The process of protein synthesis involves transcription of DNA to mRNA and then translation of mRNA to proteins.
1. DNA replication is semi-conservative. Helicase unwinds the DNA double helix, DNA polymerase links nucleotides to form new strands using the existing strands as templates.
2. Transcription creates mRNA from DNA templates using RNA polymerase.
3. Translation uses the genetic code to synthesize polypeptides from mRNA. tRNAs with anticodons complementary to mRNA codons carry amino acids which are linked by the ribosome.
1. DNA contains the genetic code and instructions for making proteins, which it stores in the cell nucleus. 2. During transcription, RNA polymerase copies DNA into messenger RNA (mRNA) which carries the code to the cytoplasm. 3. In translation, ribosomes use mRNA to produce proteins according to the genetic code by linking amino acids specified by mRNA codons. 4. Newly formed proteins travel to the endoplasmic reticulum and Golgi body for processing and packaging before use in the cell.
This document discusses the phenomenon of ab initio DNA synthesis, where DNA polymerases can synthesize new DNA strands without a template. It provides a history of the discovery of this process and studies showing DNA polymerases can generate short repetitive sequences on their own. The document also explores how adding other enzymes like restriction endonucleases, nicking endonucleases and helicase can stimulate ab initio DNA synthesis. Finally, it proposes models for how this template-independent DNA synthesis may occur and discusses potential functional roles and implications.
The document provides information on the structure of DNA and RNA. It discusses how DNA was discovered to have a double helix structure by Watson and Crick in 1953 based on prior work by scientists like Franklin, Wilkins, Chargaff and Pauling. It describes the key components of DNA including the sugar-phosphate backbone, nitrogenous bases, and how the bases pair up in the double helix structure. It also discusses different DNA structures like A, B and Z-DNA and how DNA packages into nucleosomes and chromosomes. For RNA, it notes that it is similar to DNA but contains the sugar ribose and base uracil instead of thymine.
1. DNA contains genetic instructions that can be copied and passed from generation to generation. It is made up of nucleotides with four bases that form base pairs to create a double helix structure.
2. DNA replication is the process where the DNA double helix unwinds and each strand serves as a template to make a new complementary strand, duplicating the DNA within the cell.
3. Genetic information flows from DNA to RNA to protein. Through transcription, DNA is used as a template to make messenger RNA (mRNA), which carries the genetic code to be translated by ribosomes into proteins.
DNA contains the genetic material of organisms in the form of nucleotides arranged in a double helix structure. The double helix is composed of two strands of nucleotides linked by hydrogen bonds between complementary nucleotide bases. DNA stores and transmits genetic information from one generation to the next through replication and cell division. It controls the development of an organism's phenotype through gene expression and can produce variations through mutation that lead to evolution over time.
RNA and protein synthesis involves two main steps: transcription and translation. During transcription, DNA is used as a template to produce mRNA through the enzymatic action of RNA polymerase. The mRNA then leaves the nucleus and binds to ribosomes for translation. During translation, tRNA brings amino acids to the ribosome according to the mRNA codon sequence. The amino acids are linked together to form a polypeptide or protein chain. Translation stops when a stop codon is reached.
Nucleic acids are macromolecules that store genetic information and provide instructions for building proteins. There are two main types: DNA and RNA. DNA contains the genetic blueprint in the form of a double-stranded structure located in the cell's nucleus. RNA is single-stranded and involved in protein synthesis. The central dogma of molecular biology describes how DNA is transcribed into RNA then translated into proteins. DNA replication is the process where DNA makes a copy of itself during cell division which involves unwinding of the DNA double helix, addition of nucleotides to form new strands, and production of two identical DNA molecules.
Replication, transcription, translation and its regulationAbhinava J V
This document summarizes key processes in DNA replication, transcription, translation, and their regulation in prokaryotes and eukaryotes. It describes how DNA makes copies of itself semiconservatively. Transcription involves RNA polymerase making an RNA copy of a DNA template. Translation uses ribosomes to convert the RNA into a polypeptide chain. Each process has initiation, elongation, and termination steps. Regulation ensures processes only occur at the right times and locations in the cell.
1. DNA (deoxyribonucleic acid) is a chemical found in the nuclei of living cells that controls chemical changes and determines cell and organism type.
2. DNA is a long molecule composed of nucleotides, each containing a sugar (deoxyribose), phosphate group, and organic base (adenine, thymine, cytosine, or guanine).
3. DNA replicates before cell division by unwinding its double helix structure and using each strand as a template to make a new partner strand, resulting in two identical DNA molecules for each daughter cell after division.
Dna replication, transcription and translationAshfaq Ahmad
DNA is made up of four nucleotides that form a double helix structure. Watson and Crick discovered that DNA replicates in a semi-conservative manner where each new DNA molecule contains one original and one new strand. DNA replication is highly regulated and involves several enzymes to ensure its accuracy and fidelity. Errors can occur but are typically corrected by DNA repair mechanisms. The information stored in DNA is used to make RNA and proteins through the central dogma of molecular biology which involves two key processes - transcription of DNA to RNA and translation of RNA to protein.
DNA contains the genetic code and is made up of nucleotides containing a sugar, phosphate, and one of four nitrogenous bases (A, T, C, G). DNA replicates via DNA polymerase which uses DNA as a template to produce new DNA strands. During transcription, RNA polymerase uses one DNA strand as a template to produce messenger RNA (mRNA), and during translation the mRNA directs the assembly of proteins from amino acids on ribosomes based on its codon sequence. Key enzymes and processes involved in DNA replication, transcription, and translation help copy genetic information and synthesize proteins.
The central dogma of biology describes the flow of genetic information: DNA is replicated to make more DNA; DNA is transcribed into mRNA; mRNA is translated into proteins. This involves three main molecules - DNA, RNA, and proteins - and three main processes - replication, transcription, and translation. The genetic code stored in DNA is used to direct the synthesis of proteins via mRNA and translation.
The document discusses protein synthesis which involves two main phases - transcription and translation. Transcription occurs in the nucleus and involves the DNA being used as a template to produce mRNA. The mRNA then undergoes processing before being exported to the cytoplasm where translation occurs, involving ribosomes and tRNA to link amino acids together using the mRNA as a template to produce a protein.
DNA replication is the process by which a cell makes an identical copy of its DNA before cell division. It involves unwinding the DNA double helix and using each strand as a template to create a new partner strand. DNA polymerase adds complementary nucleotides to each new strand. When complete, the process generates two identical DNA double helices from the original. Before a cell divides, it must replicate its DNA so that the resulting daughter cells have the same genetic information as the parent cell.
The document summarizes the process of protein synthesis from DNA to proteins. It describes how nucleic acids like DNA and RNA carry genetic information through their sequence of nucleotides. DNA is transcribed into mRNA in the nucleus, then mRNA is translated by ribosomes in the cytoplasm to produce proteins based on the mRNA's codon sequences. Transfer RNA molecules bring amino acids to the ribosome according to each codon, and the amino acids are joined through peptide bonds to form a polypeptide chain.
DNA is made up of nucleotides containing a phosphate group, deoxyribose sugar, and one of four nitrogenous bases. It takes the shape of a double helix with the bases on each strand complementary to each other. DNA replicates semi-conservatively prior to cell division. Transcription produces mRNA from a DNA template by copying one of the DNA strands. Translation then uses the mRNA to produce a polypeptide chain according to the genetic code, where three-nucleotide codons correspond to specific amino acids.
DNA contains the genetic instructions that determine all the characteristics of living organisms. It is made up of nucleotides containing nitrogenous bases, a phosphate group, and a sugar. The bases adenine, guanine, cytosine, and thymine form base pairs between two DNA strands that coil together in the shape of a double helix. DNA stores and transmits genetic information to make proteins through replication and transcription. During replication, DNA makes copies of itself before cell division. Transcription produces messenger RNA from DNA, which carries instructions to the ribosome for protein production through translation.
DNA is made up of nucleotides containing nitrogen bases, sugars and phosphates. The bases on two DNA strands bond together through complementary base pairing between adenine and thymine, and cytosine and guanine. DNA replicates semi-conservatively through initiation, elongation, and termination steps. RNA carries instructions from DNA for protein production. Transcription involves RNA polymerase making mRNA from DNA. Translation uses mRNA, tRNAs, and ribosomes to assemble amino acids into proteins according to the genetic code of three-base codons. Mutations in DNA can alter codons and cause changes in protein sequences.
The document summarizes key concepts about DNA, RNA, and protein synthesis. It discusses:
1) The structure of DNA as a double helix with nucleotides containing nitrogen bases that allow the strands to replicate.
2) Chromosomes contain DNA and package it tightly for storage in eukaryotic cells. DNA replication results in two DNA molecules each with one original and one new strand.
3) RNA acts as a messenger to transfer DNA instructions to the cell. Transcription and translation lead to protein synthesis on ribosomes according to the genetic code.
4) Mutations can occur through changes to nucleotides and can impact protein function, though most do not affect the organism.
The document discusses the composition and structure of nucleic acids. It defines nucleic acids as polymers of nucleotides, which consist of a sugar, phosphate group, and a nitrogenous base. DNA and RNA are two types of nucleic acids that differ in their sugar component - DNA contains deoxyribose while RNA contains ribose. The bases found in DNA are adenine, guanine, cytosine, thymine, and in RNA, uracil replaces thymine. Nucleic acids store and transmit genetic information through the processes of replication, transcription, and translation.
DNA replication is the process by which a cell makes an identical copy of its DNA before cell division. It involves unwinding the DNA double helix and using each strand as a template to create a new partner strand through complementary base pairing. DNA polymerase adds nucleotides to the new strands to replicate the DNA. This ensures each daughter cell has an exact copy of the original DNA.
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
Genetic Codon The Three nucleotide base sequence in mRNA that act as code words for amino acids in protein constitute the genetic code or codons.
There are 64 different combinations of three base codons composed of Adenine (A), Guanine (G), Cytosine (C) and Uracil (U).
Written from the 5-’ end to 3’ end.
UAA,UAG & UGA do not code for amino acid. They are called as stop codon or non sense codon.
Characteristics of Genetic Code are:
University: same codon for same amino acid in all living organism.
Specificity: A particular codon will code for the same amino acid,highly specific or unambiguous.
Non overlapping : read from a fixed point as a continuous base sequence.
Degenerate: Most of the amino acids have more than one codon. 61 codons available to code for only 20 amino acids.
DNA :DNA stands for Deoxy Ribonucleic acid.
It’s the genetic code that determines all the characteristics of living organism.
DNA is a double stranded molecule, made up of two chains of nucleotides. Nucleotides consist of three subunits : a sugar, a phosphate group and a nitrogen base pair.
Sugar present is Deoxyribose and Nitrogen bases are :
Adenine (A)
Guanine (G)
Cytosine (C)
Thymine (T)
Structure of DNA : Double helical structure of DNA was proposed by James Watson and Francis Crick in 1953.
Features of model of DNA are:
DNA is a right handed double helix, have two polydeoxyribonucleotide chains twisted around each other on a common axis.
Two strands are antiparallel i.e., one strand runs in the 5’ to 3’ direction while the other in 3’ to 5’ direction.
The diameter of helix is 20 A° (2nm).
Each turn of the helix is 34 A° (3.4 nm) with 10 pairs of nucleotides, each pair placed at a distance of about 3.4 A°.
The two strands are held together by Hydrogen bonds formed by complementary base pairs. The A-T pair has 2 hydrogen bonds while G-C pair has 3 hydrogen bonds.
The complementary base pairing in DNA helix proves Chargaff’s rule. The content of adenine equals to that of thymine (A=T) and guanine equals to that of the cytosine (G≡C).
Function of DNA
RNA
DNA replication
Transcription
Translation
DNA structure and protein synthesis .pdficefairy7706
This document discusses nucleic acids and protein synthesis. It begins by describing the structures of DNA and RNA, which are made up of nucleotides containing phosphate, sugar (ribose or deoxyribose), and nitrogenous bases. DNA contains the bases adenine, cytosine, thymine, and guanine, while RNA contains adenine, cytosine, uracil, and guanine. The document then explains DNA replication, which involves unwinding the DNA double helix and using each strand as a template to synthesize a new complementary strand. It also describes transcription of DNA into mRNA and translation of mRNA into proteins, which occurs on ribosomes and involves transfer RNA bringing amino acids to be joined into polypeptide chains according to
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2. 11.1 DNA AND RNA
STRUCTURE
AND FUNCTION
In this section, the following objectives will be covered:
Describe the structure of the DNA molecule.
List and explain the steps in the replication of DNA.
Compare and contrast the structure of RNA with DNA.
List the three major types of RNA and describe their functions.
3. Controversy over whether DNA or protein was the genetic message
Experiment using viruses showed only DNA directed the formation of new viruses
It took years for investigators to conclude Mendel’s factors (genes) were
on chromosomes.
Mendel knew nothing about DNA.
4. 11-4
Alfred Hershey and Martha
Chase determined that DNA is
the genetic material.
Their experiment involved a virus
that infects bacteria, such as E.
coli.
They wanted to know which part of
the virus entered the bacterium
•Capsid made of protein
•DNA inside the capsid
Radioactive tracers showed that
DNA, not protein, enters the
bacterium and guides the
formation of new viruses.
Therefore, DNA must be the
genetic material.
5.
6. STRUCTU
RE OF
DNA
• Race to determine the
structure
• Chargaff’s rules
• Knew DNA contains four types
of nucleotides
• Examined DNA from many
species
• The amount of A, T, G, and C
in DNA varies from species
to species.
• In each species, the amount
of A = T and the amount of G
= C.
• All nucleotides contain
phosphate, a 5-carbon sugar,
and a nitrogen-containing
base.
7.
8. 11-8
Rosalind Franklin was studying
the structure of DNA.
Her data showed DNA to be a
helix with some portions
repeating over and over.
9. 11-9
1951—James Watson and
Francis Crick set out to bring
together all the data on DNA
and build a model
The model suggested how
replication works.
Their model holds true today
with few changes.
Won the Nobel Prize
10. DNA
STRUCTU
RE
• DNA structure is a double
helix, like a twisted ladder
• Deoxyribose sugar and
phosphate molecules are
bonded, forming the sides,
with the bases making up the
rungs of the ladder.
• Complementary base pairing of
A&T and G&C
• Hydrogen bonding between the
bases holds the halves of the
helix together.
12. Process of copying DNA before cell division
Two strands separate
•Each strand serves as a template for a new strand
Semiconservative—each new DNA molecule is
made of one parent strand and one new strand
Replication requires
•Unwinding—helicase
•Complementary base pairing
•Joining—DNA polymerase and DNA ligase
New DNA molecule exactly identical to
original molecule
13. Parent strand unwinds and separates by
actions of helicase
New strands form through
complementary base pairing by actions of
DNA polymerase.
DNA ligase seals any breaks in the sugar-
phosphate backbone.
New DNA molecule will be half old and
half new
New DNA molecule will be exactly
identical to original molecule
15. DNA
REPLICAT
ION IN
EUKARYO
TES
In eukaryotes, DNA replication
begins at numerous origins of
replication.
• Forms “replication bubbles”
• Bubbles spread in both directions
until they meet.
16.
17. RNA
STRUCTU
RE AND
FUNCTIO
N
• Ribonucleic acid (RNA)
• Contains sugar ribose
• Uses uracil, not thymine
• Uses A, C, and G like DNA
• Single-stranded
• Three major types
• Messenger RNA (mRNA)
• Transfer RNA (tRNA)
• Ribosomal RNA (rRNA)
18.
19. 11-19
S I MILARITIES O F D NA AND RNA
Both are composed of nucleotides.
Both are nucleic acids.
D I FFERENCES BETWEEN D NA AND RNA
Both have four different types of bases.
Both have a sugar-phosphate backbone.
DNA RNA
Found in nucleus Found in nucleus and
cytoplasm
Genetic material Helper to DNA
Sugar is deoxyribose. Sugar is ribose.
Bases are A,T,C,G. Bases are A,U,C,G.
Double-stranded Single-stranded
DNA is transcribed (to give a
variety of RNA molecules).
mRNA is translated
(to make proteins).
20. THREE
TYPES
OF RNA
• Messenger RNA (mRNA)
• Produced in the nucleus from DNA
template
• Carries genetic message to ribosomes
• Transfer RNA (tRNA)
• Produced in the nucleus from DNA
template
• Transfers amino acids to ribosomes
• Each type carries only one type of
amino acid
• Ribosomal RNA (rRNA)
• Produced in the nucleolus of the
nucleus from DNA template
• Joins with proteins to form ribosomes
• Ribosomes may be free or in
polyribosomes (clusters) or attached to
ER
21. 11.2 GENE
EXPRESSION
In this section, the following objectives will be covered:
Describe the processes of transcription and translation.
Summarize the steps involved in gene expression and how it
uses the genetic code.
22. 11-22
• First to suggest a link
between genes and
proteins
Early 1900s, Sir
Archibald Garrod
suggests a
relationship between
inheritance and
metabolic diseases
• Information flows from
DNA to RNA to protein
DNA provides a
blueprint to
synthesize proteins.
23. 11-23
Transcription
•DNA serves as template to make mRNA
Translation
•mRNA directs sequence of amino acids in a
protein
•rRNA and tRNA assist
24. 11-24
DNA: sequence of bases
is genetic information.
Transcription: genetic
information is passed
from DNA to mRNA.
Translation: amino acids
in a polypeptide are
sequenced as specified by
the template DNA strand.
25. THE
GENETIC
CODE
• Translates from nucleic acids
to amino acids
• Triplet—3 nucleotide sequence
in DNA
• Codon—3 nucleotide sequence
in mRNA
• A codon encodes a single amino
acid.
• Start and stop codons
26. 11-26
Second base U Second base C Second base A Second base G
First base U UUU phenylalanine (Phe) UCU serine (Ser) UAU tyrosine (Tyr) UGU cysteine (Cys) Third base U
First base U UUC phenylalanine (Phe) UCC serine (Ser) UAC tyrosine (Tyr) UGC cysteine (Cys) Third base C
First base U UUA leucine (Leu) UCA serine (Ser) UAA stop UGA stop Third base A
First base U UUG leucine (Leu) UCG serine (Ser) UAG stop UGG tryptophan (Trp) Third base G
First base C CUU leucine (Leu) CCU proline (Pro) CAU histidine (His) CGU arginine (Arg) Third base U
First base C CUC leucine (Leu) CCC proline (Pro) CAC histidine (His) CGC arginine (Arg) Third base C
First base C CUA leucine (Leu) CCA proline (Pro) CAA glutamine (Gln) CGA arginine (Arg) Third base A
First base C CUG leucine (Leu) CCG proline (Pro) CAG glutamine (Gln) CGG arginine (Arg) Third base G
First base A AUU isoleucine (Ile) ACU threonine (Thr) AAU asparagine (Asn) AGU serine (Ser) Third base U
First base A AUC isoleucine (Ile) ACC threonine (Thr) AAC asparagine (Asn) AGC serine (Ser) Third base C
First base A AUA isoleucine (Ile) ACA threonine (Thr) AAA lysine (Lys) AGA arginine (Arg) Third base A
First base A AUG methionine (Met) (start) ACG threonine (Thr) AAG lysine (Lys) AGG arginine (Arg) Third base G
First base G GUU valine (Val) GCU alanine (Ala) GAU aspartic acid (Asp) GGU glycine (Gly) Third base U
First base G GUC valine (Val) GCC alanine (Ala) GAC aspartic acid (Asp) GGC glycine (Gly) Third base C
First base G GUA valine (Val) GCA alanine (Ala) GAA glutamic acid (Glu) GGA glycine (Gly) Third base A
First base G GUG valine (Val) GCG alanine (Ala) GAG glutamic acid (Glu) GGG glycine (Gly) Third base G
27. • During transcription,
complementary RNA is made from
a DNA template.
• Portion of DNA unwinds and unzips
at the point of attachment of RNA
polymerase
• Bases join in the order dictated by
the sequence of bases in the
template DNA strand.
TRANSCRI
PTION
28. 11-28
Transcription is taking
place- the nucleotides of
mRNA are joined by the
enzyme RNA polymerase in
an order complementary to
a strand of DNA.
This mRNA transcript is
ready to be processed.
29. Newly made pre-mRNA must be processed.
• Capping and addition of poly-A tail provides stability
• Introns (non-coding) removed
• Leaves only exons (coding)
• Alternative splicing can produce different versions of mRNA
leading to different proteins.
• Now mature mRNA leaves nucleus and associates with ribosome
on cytoplasm.
31. 11-31
Ribosomes are composed of protein and rRNA.
Site of translation—protein synthesis
Binds mRNA and two tRNA molecules
P site for a tRNA attached to a peptide
A site for newly arrived tRNA with an amino acid
32. TRANSLA
TION
OVERVIE
W
tRNA brings amino acids to
the ribosome to join with
mRNA codon
Anticodon—group of three
bases complementary to a
specific codon of mRNA
After translation is complete,
a protein contains the
sequence of amino acids
originally specified in the
DNA.
33.
34. TRANSL
ATION
Three stages of translation in detail
• Initiation
• mRNA binds to small subunit of
ribosome
• Large subunit then joins
• Elongation
• Peptide lengthens one amino acid at a
time
• Termination
• 1 of 3 stop codons reached
• Release factor causes ribosomal
subunits and mRNA to dissociate
• Complete polypeptide released
35. 11-35
A small ribosomal subunit
binds to mRNA; an initiator
tRNA pairs with the mRNA
start codon AUG. The large ribosomal subunit
completes the ribosome.
Initiator tRNA occupies the
P site. The A site is ready
for the next tRNA.
36. 11-36
1. A tRNA-amino acid
approaches the ribosome
and binds at the A site.
2. Two tRNAs can be at a
ribosome at one time;
the anticodons are
paired to the codons.
3. Peptide bond formation
attaches the peptide
chain to the newly
arrived amino acid.
4. The ribosome moves forward; the
“empty” tRNA exits from the E
site; the next amino acid-tRNA
complex is approaching the
ribosome.
37. 11-37
The release factor hydrolyzes the bond
between the last tRNA at the P site and
the polypeptide, releasing them. The
ribosomal subunits dissociate.
The ribosome comes to a stop
codon on the mRNA. A release
factor binds to the site.
38.
39. 11.3 GENE
REGULATION
In this section, the following objectives will be covered:
Explain the operation of the lac operon in prokayotes and how it
controls gene expression.
Describe the levels of control of gene expression in eukaryotes.
40. 11-40
GENE REGULATION
There are levels of gene
expression control:
• Body contains many cells that
differ in structure and
function
• Only certain genes are active
in cells that perform
specialized functions
• Housekeeping genes govern
functions common to all cells
• Activity of selected genes
accounts for specialization
Gene expression in
specialized cells
41. •E.coli does not normally transcribe the genes of the lac operon.
•When lactose is not present, repressor binds to the operator and RNA polymerase
cannot attach to the promoter and inhibits transcription
Operon—cluster of bacterial genes along with DNA control sequence
François Jacob and Jacques Monod—Nobel Prize 1961 for lac operon
If we drink milk, E. coli immediately begins to make three enzymes
needed to metabolize lactose.
Escherichia coli lives in our intestine and can quickly adjust its
enzymes according to what we eat.
42. When lactose is present, it binds to the repressor.
• Repressor is inactivated and cannot attach to operator
• RNA polymerase can bind and transcription occurs.
• System can also work for genes normally turned on
• Binding of tryptophan (gene for synthesis normally on) causes
operator to be turned off
43. a.Lactose is absent-operon is
turned off.
Enzymes needed to
metabolize lactose are not
produced.
a.Lactose is present-operon is
turned on.
Enzymes needed to
metabolize lactose are
produced.
44. Each gene has its own promoter.
Employ a variety of mechanisms
•Affect whether gene is expressed, speed
of expression, and length of expression
Some mechanisms occur in
nucleus and others in cytoplasm
•Nucleus—chromatin condensation,
mRNA transcription, and mRNA
processing
•Cytoplasm—delay of transcription,
duration of mRNA or protein
45.
46. CHROMAT
IN
CONDENS
ATION
• Way to keep genes turned off
• More tightly compacted = less
gene expression
• Heterochromatin—dark
staining regions of tightly
compacted, inactive chromatin
• Barr body—second X
chromosome in mammalian
females
• Which X is inactivated? —
female tortoiseshell cat
48. EUCHRO
MATIN
• Unpacked heterochromatin
• Contains active genes
• Nucleosome—portion of DNA
wrapped around histones
• Transcription activator pushes
aside histones so that
transcription can begin.
49.
50. Same principles as prokaryotic transcription
but with more regulatory proteins per gene
Allows for greater control but also a greater
chance for malfunction
Transcription factors—DNA-binding proteins
that help RNA polymerase bind to a
promoter
• Several needed in each case, need all of
them
• Form complex that helps pull apart helix
and helps position RNA polymerase
• Same ones used in different combinations
• If one is defective, it can have serious
effect—Huntington disease
• Speed up transcription
• Bind to enhancer region of DNA
DNA
TRANSCRI
PTION IN
EUKARYO
TES
51.
52. 11-52
Possible for a single
transcription factor to
have dramatic effect on
gene expression
MyoD alone can
activate the genes
necessary for
fibroblasts to become
muscle cells.
Ey can bring about
the formation of a
complete eye in flies.
53. • After transcription, introns must
be removed and exons spliced
together.
• Alternative mRNA processing
allows cells to produce multiple
proteins from the same gene by
changing the way exons are joined.
• Fruit fly DScam gene can produce
over 38,000 different combinations
MRNA
PROCESSI
NG
54.
55. MRNA
TRANSLA
TION
• Cytoplasm contains proteins
that determine whether
translation takes place.
• Environmental conditions can
delay translation.
• Red blood cells do not produce
hemoglobin unless heme is
available.
• The longer mRNA remains in
the cytoplasm before it is
broken down, the more gene
product is produced.
• It can be affected by length of
poly A tail or presence of
hormones.
56. • Some proteins are not active
immediately after synthesis.
• Insulin must be processed
before it is an active form.
• Allows protein’s activity to be
delayed until needed
57. In multicellular organisms, cells
are constantly sending out
chemical signals that influence the
behavior of other cells.
• During development, signals determine
what a cell becomes.
• Later, they help coordinate growth and
daily functions.
Cell-signaling pathway
• Begins when chemical signal binds to
receptor on target cell plasma membrane
• Initiates signal transduction pathway
• End product affects cell (not original signal
itself)
59. CHAPTER 11 OBJECTIVE
SUMMARY
You should now be able to:
1. Describe the structure of the DNA molecule.
2. List and explain the steps in the replication of DNA.
3. Compare and contrast the structure of RNA with DNA.
4. List the three major types of RNA and describe their
functions.
5. Describe the processes of transcription and translation.
6. Summarize the steps involved in gene expression and
how it uses the genetic code.
7. Explain the operation of the lac operon in prokayotes
and how it controls gene expression.
8. Describe the levels of control of gene expression in
eukaryotes.