* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Download the genetic material
Mitochondrial DNA wikipedia , lookup
DNA profiling wikipedia , lookup
Genomic library wikipedia , lookup
Cancer epigenetics wikipedia , lookup
No-SCAR (Scarless Cas9 Assisted Recombineering) Genome Editing wikipedia , lookup
SNP genotyping wikipedia , lookup
Expanded genetic code wikipedia , lookup
Polyadenylation wikipedia , lookup
RNA silencing wikipedia , lookup
Messenger RNA wikipedia , lookup
Microevolution wikipedia , lookup
Genealogical DNA test wikipedia , lookup
DNA damage theory of aging wikipedia , lookup
Bisulfite sequencing wikipedia , lookup
United Kingdom National DNA Database wikipedia , lookup
DNA vaccination wikipedia , lookup
Gel electrophoresis of nucleic acids wikipedia , lookup
DNA polymerase wikipedia , lookup
Epigenomics wikipedia , lookup
Molecular cloning wikipedia , lookup
Genetic code wikipedia , lookup
Cell-free fetal DNA wikipedia , lookup
Point mutation wikipedia , lookup
Vectors in gene therapy wikipedia , lookup
Nucleic acid tertiary structure wikipedia , lookup
History of genetic engineering wikipedia , lookup
Non-coding DNA wikipedia , lookup
Extrachromosomal DNA wikipedia , lookup
History of RNA biology wikipedia , lookup
Non-coding RNA wikipedia , lookup
DNA supercoil wikipedia , lookup
Cre-Lox recombination wikipedia , lookup
Epitranscriptome wikipedia , lookup
Nucleic acid double helix wikipedia , lookup
Therapeutic gene modulation wikipedia , lookup
Helitron (biology) wikipedia , lookup
Artificial gene synthesis wikipedia , lookup
Primary transcript wikipedia , lookup
DNA & RNA THE GENETIC MATERIAL Vocabulary you should know… DNA: (deoxyribonucleic acid) the material that contains the information that determines inherited characteristics Nucleotide: in a nucleic-acid chain, a sub-unit that consists of a sugar, a phosphate, & a nitrogenous base More Vocab… Nitrogenous base: an organic base that contains nitrogen, such as a purine or pyrimidine; a sub-unit of a nucleotide in DNA or RNA Purine: a nitrogenous base that has a doublering structure; one of two general categories of nitrogenous bases found in DNA & RNA; either adenine or guanine More Vocab… Pyrimidine:a nitrogenous base that has a single-ring structure; one of the two general categories of nitrogenous bases found in DNA& RNA; thymine, cytosine or uracil Base-Pairing Rules: the rules stating that cytosine pairs w/ guanine & adenine pairs w/ thymine in DNA & adenine pairs w/ uracil in RNA More Vocab… Complementary Base Pair: the nucleotide bases in one strand of DNA or RNA that are paired w/ those of another strand; adenine pairs w/ thymine or uracil, and guanine pairs with cytosine Base Sequence: the order of nitrogenous bases on a chain of DNA Double Helix: shape of a DNA molecule formed when two twisted DNA strands are coiled into a springlike structure & held together by hydrogen bonds b/t the bases DNA – deoxyribonucleic acid The genetic information for an organism DNA contains the instructions that cells need to make every protein required for essential life functions Found mostly in the nucleus of cells Composed of 100’s of 1000’s of repeating units of nucleotides DNA Photographed through x-ray crystallography by Rosalind Franklin in the 1950s (w/ help from Maurice Wilkins) 1st model was created by James Watson & Francis Crick in the ‘50s, with the use of Franklins x-ray crystallography picture Rosalind Franklin Maurice Wilkins James Watson & Francis Crick DNA Made of subunits called nucleotides: 1 phosphate group 1 deoxyribose – simple sugar **this is what DNA is named for 1 of 4 nitrogen bases Either purines or pyrimidines NITROGEN BASES Purines: double ringed structure Adenine (A) Guanine (G) Nitrogenous Bases Pyrimidines: single ringed structure Thymine (T) Cytosine (C) STRUCTURE OF DNA Shape: double helix – repeating units of nucleotides **the sequence of nucleotides determines gene function DOUBLE HELIX 2 chains of nucleotide monomers running anti - parallel Phosphate groups make up the backbone of the double helix Covalent bonds hold the nucleotides together by connecting the deoxyribose of one nucleotide to the phosphate group of the adjacent nucleotide Double Helix Cont’d The nitrogen bases of the nucleotides pair up to link the 2 helixes hydrogen bonds b/t the nitrogen bases hold the strands of the double helix together Double Helix Structure Base-Pairing Rules Adenine (A) & Thymine (T) are always together Cytosine (C) & Guanine (G) must then pair together DNA Basics Quiz 1. What is DNA? 2. The first person to photograph DNA was ____________. 3. The first people to make a model of DNA were ________ & ______. 4. A strand of DNA is made up of repeating units of __________. DNA Basics Quiz Cont’d 5. A nucleotide is composed of 3 parts, name all three. 6. List the 4 different nitrogenous bases. 7. Which part of the nucleotide makes up the backbone of the strand of DNA? DNA Basics Quiz Cont’d 8. What type of bonds hold the deoxyribose of one nucleotide to the phospate of the adjacent one? 9. What type of bonds hold the complementary nitrogenous bases together? 10. Out of Adenine, Guanine, Cytosine & Thymine, tell me the two complementary pairs. DNA Technology DNA is manipulated for many different reasons: Crime scene analysis Genetic counseling Research Treatment of disease DNA Technology DNA ID Only identical twins have identical DNA Only 10% of the human genome varies between all humans The 10% that differs falls on the same chromosome region so we can isolate this DNA and use it to make important discoveries Identifying DNA Step 1: Copying DNA: Polymerase Chain Reaction Method of quickly copying DNA from small samples Step 2: Cutting DNA: Restriction Enzymes Restriction enzymes recognize specific short DNA sequences & cut in or near them This isolates the DNA needed for ID Identifying DNA cont’d Step 3: Sorting DNA by Size: Gel Electrophoresis Gel electrophoresis separates DNA according to size and charge Does this by running an electrical current through gel that the DNA cut by the restriction enzymes has been placed in, + & - charged pieces move to opposite ends The resulting pattern is called the DNA fingerprint Identifying DNA Step 4: Comparing DNA: DNA Fingerprints Compare the DNA sample to other DNA fingerprints until you find a match, or pattern that you are looking for Accuracy?? The odds that 2 people will share the same DNA fingerprint: 1: 100 billion # of people on Earth: approx 7 billion Gel Electrophoresis Recombinant DNA Genetic engineering: the process of altering the genetic material of cells or organisms to allow them to make new substances DNA recombination/Recombinant DNA: Joining together DNA from two different organisms DNA Recombination Step 1: isolate the DNA and the plasmid of interest Plasmids: small rings of DNA found naturally in some bacterial cells in addition to the main bacterial chromosome Step 2: restriction enzymes cut the DNA into fragments Step 3: fragments and plasmid DNA are joined together permanently by DNA ligase DNA Recombination Cont’d Step 4: recombinant DNA plasmids, each with different fragments of DNA, are inserted into bacterial cells These recombinant DNA plasmids are then copied each time the bacterial cell copies its own DNA Step 5: once a colony of bacterial cells containing the recombinant DNA plasmids is created, the recombinant DNA is removed to be used Recombinant DNA Central Dogma of Molecular Genetics How we go from DNA to RNA 1. replication (DNA copies itself) 2. transcription (DNA acts as a template for the production of messenger RNA (mRNA)) 3. translation (mRNA carries coded information to ribosomes; ribosomes "read" this information and use it to make proteins) The Central Dogma Cont’d Dogma Cont’d Replication: know… Vocab you should DNA replication: process by which DNA is copied in a cell before a cell divides by mitosis, meiosis or binary fission Helicase: enzymes that separate DNA strands by breaking the hydrogen bonds that hold the nitrogenous bases together Replication: More vocab… Replication Fork: a Y shaped point that results when the two strands of DNA double helix separate so that the DNA molecule can be replicated DNA Polymerase: an enzyme that catalyzes the formation of the DNA molecule Replication: More Vocab… Semi-conservative Replicaiton: in each new DNA double helix, one strand is from the original molecule & one strand is new Mutation: a change in the nucleotide-base sequence of a gene or DNA molecule Facts about Replication Occurs during interphase of both the cell cycle for mitosis and for meiosis Happens to all of the DNA in the cell, not just selected parts (every chromosome) Replication (of DNA) 1. Strands of DNA separate a) Helicase enzymes move along the strand of DNA b) They break the hydrogen bonds between the nitrogen bases c) The two strands separate, exposing a a Y-shaped region called the replication fork Replication: Helicase & the Replication Fork Replication Cont’d 2. DNA polymerase enzymes add complementary nucleotides to the two separated strands a) The nucleotides are found free-floating around inside the nucleus b) As the nucleotides are added, covalent bonds form b/t the deoxyribose of one and the phosphate of the next Replication: Cont’d Adding Nucleotides 2. Adding nucleotides cont’d c) Hydrogen bonds are formed b/t the nitrogenous bases from the original strand and the nitrogenous bases on the newly added nucleotides Replication: Cont’d Adding Nucleotides 2. Adding Nucleotides cont’d d) DNA synthesis (creation) occurs in different directions on each strand i. As the replication fork moves along the original DNA, synthesis of one strand, the leading strand, follows the movement of the replication fork ii. Synthesis of the other strand, the lagging strand, moves in the opposite direction, away from the replication fork Replication: Cont’d Adding Nucleotide 2. Adding Nucleotides Cont’d e) Because the nucleotides are added to the leading and lagging strands in opposite directions, it leaves gaps in the newly synthesized DNA, called Okazaki Gaps f) These gaps are later joined together by the enzyme DNA ligase Replication: Strands Leading & Lagging Replication Okazaki Fragments Replication Cont’d 3. DNA polymerase enzymes finish replicating the DNA & fall off The result of replication of a strand of DNA is two completely identical strands of DNA, each containing one old strand & one new stand = semiconservative replication Semi-Conservative Replication Replication cont’d DNA replication flash interactive DNA Replication Quiz 1. What are the three parts of the Central Dogma of molecular genetics? 2. What is the first thing that must happen in order for DNA to replicate itself? 3. What is the name of the enzyme that separates the two strands of DNA? Replication Quiz Cont’d 4. Helicase breaks the ________ bonds that hold the nitrogenous bases together. 5. The Y-shaped region that appears as the two strands separate is called the ________ _______. 6. After the strands separate, what is the second thing that happens as DNA replicates itself? Replication Quiz Cont’d 7. What is the name of the enzyme that adds the free-floating nucleotides to the two exposed strands of DNA? 8. The gaps created as the new DNA strands are being synthesized are called _________ __________. Replication Quiz Cont’d 9. What happens to the DNA polymerase after is finished being replicated? 10. Replication results in _____ (#) strands of DNA, each having one ____ strand and one _______ strand. RNA: Vocabulary You Should Know Ribonucleic Acid (RNA): a natural polymer that is present in all living cells & that plays a role in protein synthesis Transcription: the process of forming a nucleic acid by using another molecule as a template; particularly the process of synthesizing RNA by using one strand of a DNA molecule as a template Translation: the portion of protein synthesis that takes place at ribosomes & that uses the codons in mRNA molecules to specify the sequence of amino acids in ploypeptide chains RNA: move vocab… Protein Synthesis: the formation of proteins by using infomration contained in DNA & carried by mRNA Ribose: a five-carbon sugar present in RNA Messenger RNA (mRNA): a single-stranded RNA molecule that encodes the information to make a protein RNA: more vocab… Ribosomal RNA (rRNA): an organelle that contains most of the RNA in the cell & that is responsible for ribosome function Transfer RNA (tRNA): an RNA molecule that transfers amino acids to the growing end of a polypeptide chain during translation RNA Polymerase: an enzyme that starts (catalyzes) the formation of RNA by using a strand of DNA molecule as a template RNA: More vocab… Promoter: a nucleotide sequence on a DNA molecule to which an RNA polymerase molecule binds, which initiates the transcription of a specific gene Termination Signal: a specific sequence of nucleotides that marks the end of a gene Genetic Code: the rule that describes how a sequence of nucleotides, read in groups of three consecutive nucleotides (triplets) that correspond to specific amino acids, specifies the amino acid sequence of a protein RNA: More Vocab… Codon: in DNA, a three-nucleotide sequence that encodes an amino acid or signifies a start signal or a stop signal Anticodon: a region of tRNA that consists of three bases complementary to the codon of mRNA Genome: the complete genetic material contained in an individual RNA – Ribonucleic Acid RNA: Structure & Comparison to DNA RNA 1. Single stranded 2. Sugar = ribose 3. Nitrogenous bases: 1. Adenine 2. Cytosine 3. Guanine 4. Uracil 4. Usually much shorter DNA 1. Double stranded 2. Sugar = deoxyribose 3. Bases: 1. Adenine 2. Cytosine 3. Guanine 4. Thymine 4. Usually much longer: 100s or 1000s of genes RNA v. DNA RNA: Types of 1. mRNA: messenger RNA Single stranded carries instruction from a gene to make a protein Eukaryotic cells: carries messages from DNA in the nucleus to a ribosome in the cell’s cytoplasm mRNA RNA: Types of … 2. tRNA: transfer RNA transports amino acids to the ribosomes (rRNA) to be assembled into proteins Made of many nucleotides linked together tRNA RNA: Types of … 3. rRNA: ribosomal RNA This type of RNA makes up a part of ribosomes Ribosomes are organelles in each cell where protein synthesis occures clamp onto the mRNA & use its info to assemble amino acids in the correct order to make proteins rRNA COMPOSITION OF RNA Made of nucleotides: 1 phosphate group 1 ribose – type of sugar 1 of 4 nitrogen bases RNA’s NITROGEN BASES Purines: Adenine (A) Guanine (G) Pyrimidines: Cytosine (C) Uracil (U) ***instead of Thymine RNA Base-Pairing Rules Adenine pairs w/ Uracil (because there is no thymine) Cytosine pairs w/ Guanine RNA BasePairing RNA Quiz 1. Protein synthesis results in the creation of 2. 3. 4. 5. 6. 7. ________. RNA has _______ strands. RNA has the sugar _________. Name the 4 bases for RNA. RNA is usually ______ than DNA. Name the 3 types of RNA. What does mRNA do? RNA Quiz Cont’d 8. What does tRNA do? 9. rRNA is found on what cell part? 10. What are the base-pairing rules for RNA? Transcription The rewriting of genetic instructions from DNA into RNA “transcribes” DNA into genes Takes place in the nucleus of eukaryotic cells Takes place in the cytoplasm of prokaryotic cells Transcription Steps 1. Unwinding & separating the DNA strands The enzyme RNA polymerase binds to a promoter (a specific codon that starts transcription) on the DNA molecule DNA unwinds & separates Transcription Steps: Separating DNA Unwinding & Transcription Steps 2. Adding RNA nucleotides to create a strand of RNA RNA polymerase adds free-floating RNA nucleotides to one of the exposed DNA strands The nucleotides that are added are complementary to one of the DNA strands Only a specific section of the DNA strand is used to create the strand of RNA Adding RNA Nucleotides Transcription Steps 3. Release of the RNA molecule RNA polymerase reaches a termination signal that tells it to stop RNA polymerase releases both the DNA & the newly formed RNA molecule RNA created is mRNA The RNA molecule is free to perform its “job” RNA polymerase is available to transcribe more genes Releasing both DNA & RNA Transcription Quiz 1. Transcription rewrites what? 2. Where does transcription take place in eukaryotic cells? 3. What is the 1st step in transcription? 4. What is the enzyme that unwinds & separates DNA? Transcription Quiz Cont’d 5. What is the second step of transcription? 6. What are added to the exposed strand of DNA? 7. What tells RNA polymerase when to stop adding nucleotides? 8. The newly formed RNA is __RNA. Transcription Quiz Cont’d 9. When RNA polymerase reaches the terminal signal it releases both _______ & _______. 10. What does RNA polymerase do after it releases the DNA & newly formed RNA molecule? Protein Synthesis Gene: segment of DNA , located on a chromosome that codes for a hereditary characteristic (like hair color) Genes direct the synthesis or making of proteins for that particular trait Genes use RNA to help make the appropriate proteins Protein Synthesis Genetic information flows in the following order: Transcription Translation / Protein synthesis DNA → RNA → protein Proteins are important b/c they create & do everything that our body is & does The Genetic Code The code needed to convert the language of mRNA into proteins Proteins are made of amino acids Amino acids are made based on the nucleotide sequence in mRNA 3 adjacent nucleotides in mRNA specify a particular amino acid The 3 nucleotide sequence that encodes an amino acid, a start signal or a stop signal = a codon Codons Codons can only code for one amino acid i.e.: UUA = Leucine and only leucine Each amino acid can be coded for by more than one codon the amino acid leucine can be coded for by all of the following codons i.e.: UUA = Leucine, UUG = Leucine CUU = Leucine, CUC = Leucine CUA = Leucine, CUG = Leucine Codons Cont’d Start codons: sequence of nucleotides in mRNA that signals where translation should begin Codes for the amino acid methionine Stop codons: sequence of nucleotides in mRNA that signals where translation should stop Does not code for any amino acid Codons in mRNA Proteins Made of polypeptides Polypeptides are chains of amino acids linked by peptide bonds 20 different amino acids Polypeptide chains are 100s of 1000s of amino acids long The sequence of amino acids determine how the protein will fold & twist into a 3d shape, the shape gives the protein its function Proteins Translation Is the synthesis or making of a protein The instructions for making a protein are transcripted from DNA into mRNA All three types of RNA are involved in translation Translation Steps 1. Joining RNAs rRNAs & tRNAs attach to a mRNA Enzymes attach an amino acid to one end of each tRNA The other end of the tRNA contains the anticodon for mRNA A tRNA carrying the amino acid methionine must be present to start the reading of mRNA & attaches to a start codon on mRNA T-RNA Translation Translation Steps Cont’d 2. Creation of a polypeptide chain tRNAs carrying correct amino acids, pair their anticodons w/ the codons on the mRNA strand Methionine detaches from the 1st tRNA after the 2nd anticodon is added A peptide bond forms b/t methionine & the 2nd amino acid to start a polypeptide chain The 1st tRNA exits the ribosome Ribosome moves one codon down on the mRNA strand Translation Translation Step Cont’d 3. Polypeptide Chains Grow mRNA continues to move through the ribosome New tRNAs w/ correct anticodons move in & peptide bonds are created b/t the amino acids of each tRNA The polypeptide chain moves from one tRNA to the next tRNA & attaches to its amino acid Translation Translation Steps 4. Stop Codon Polypeptide grows one amino acid at a time until it reaches a stop codon Polypeptide falls off Translation Translation Steps Cont’d 5. End of Translation All the parts that are needed for translation come apart The last tRNA exits the ribosome The ribosome moves away from the mRNA All the parts are free to be used over & over again Translation Translation Quiz 1. Proteins are made of ____ ____, which are made of 3 RNA ______. 2. Polypeptides are chains of amino acids linked by _____ ____. 3. Translation is the synthesis of ________. 4. List the types of RNA involved in protein synthesis. Translation Quiz Cont’d 5. The first tRNA to be used during translation must carry the amino acid ________. 6. A polypeptide chain is started when methionine is bonded to the __________. 7. For the polypeptide chain to grow the mRNA must ____________. Translation Quiz Cont’d 8. The polypeptide chain stops growing when it reaches the ______ ________. 9. When the polypeptide chain reaches the stop codon what happens to the chain? 10. Once the polypeptide chain falls off, what happens to all the parts that assembled to translate RNA?