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Nucleic Acids and Protein Synthesis. Modern Biology Chapter 10. DNA Structure. 10-1. DNA. full name is D eoxyribo N ucleic A cid. A Nucleotide. The monomer of nucleic acids…. Structure of DNA. Basic Structure three basic components deoxyribose : 5 C sugar. Structure of DNA.
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Nucleic Acids and Protein Synthesis Modern Biology Chapter 10
DNA full name is DeoxyriboNucleicAcid
A Nucleotide The monomer of nucleic acids…
Structure of DNA • Basic Structure • three basic components • deoxyribose: 5 C sugar
Structure of DNA • Basic Structure • three basic components • phosphate group (PO4)3-
Structure of DNA Basic Structure three basic components nitrogenous base adenine (A) guanine (G) thymine (T) cytosine (C)
Structure of DNA • The double helix • many scientists worked to solve the structure of DNA
Chargaff • Concluded that A must bond with T and C with G
Structure of DNA • The double helix • many scientists worked to solve the structure of DNA • Rosalind Franklin • took X-ray photographs of DNA • died in 1958 without recognition for her enormous contribution
Structure of DNA • The double helix • many scientists worked to solve the structure of DNA • Wilkins • received Nobel prize with Watson and Crick
Structure of DNA • The double helix • many scientists worked to solve the structure of DNA • Watson and Crick • first to construct a model of DNA molecule • received Nobel prize for their work in 1962 • Primarily piggy-backed on others’ work, but were the first to put the pieces together correctly
Structure of DNA The double helix • two nucleotide chains that wrap around each other • base-pairs form the rungs of the ladder
Structure of DNA • The double helix • alternating chains of phosphate groups and deoxyribose molecules form the backbone of the structure • all rungs are of equal length • approx. 10 base pairs per turn of DNA molecule
Structure of DNA • Complementary base pairing • to ensure that the rungs are of equal length nucleic acids pair up • base-pairing rules • cytosine bonds with guanine (C-G) • adenine bonds with thymine (A-T)
Structure of DNA connected by hydrogen bonds • C and G share 3 H-bonds • A and T share 2 H-bonds
Replication of DNA • replication: process of copying DNA • the steps: • double chains must separate between the nucleic acids • replication fork: point at which the chains separate • helicase: enzyme that breaks apart DNA molecule • nucleotide bases match up with their compliments • DNA polymerase: enzyme that assembles new bases to original strand
Replication of DNA • replication: process of copying DNA • complimentary bases allow for accurate replication • new strands of DNA actually contain one old strand and one new strand
A movie for your viewing enjoyment Animation Illustrating DNA Replication by Complementary Base Pairing • More complex view
Replication of DNA • Accuracy and Repair • highly accurate with only 1 error per 10,000 pairs • mutation: change in a nucleotide sequence
Replication of DNA • Accuracy and Repair • proofreading and repair reduce error rate to 1 error per 1,000,000,000 base pairings • enzymes proofread and repair any errors that are identified • Equivalent to 1,488,095 copies of Huckleberry Finn
Replication of DNA • Accuracy and Repair • some factors increase the rate at which DNA mutates • radiation • certain chemicals • sun light
Radiation Excited electrons run around uncontrollably and cause problems. We use this trait for helping patients battle cancer- chemo therapy.
RNA Modern Biology Chapter 10
Structure of RNA • full name is RiboNucleic Acid
Structure of RNA basic structure • backbone of phosphate groups and ribose • single stranded • uracil (U) replaces thymine in pairing with adenine
Types of RNA • mRNA: messenger RNA • carries copy of DNA strand from nucleus to ribosome • single, uncoiled chain
Types of RNA • tRNA: transfer RNA • carries specific amino acids to ribosomes to pair with mRNA • single chain (about 80 base pairs long) folded into a hairpin like shape
Types of RNA rRNA: ribosomal RNA • Along with proteins rRNA forms ribosomes • globular form
Transcription • process where genetic information is copied from DNA to RNA • ANIMATION OF THE PROCESS OF TRANSCRIPTION
Transcription • steps of transcription • RNA polymerase binds to DNA in specific sites called promoter regions • DNA unzips and nucleic bases follow complementary base-pairing rules • Termination sequence marks end of transcription • products of transcription are all forms of RNA • Movie Time
DNA unzips • RNA polymerase does it’s thing • RNA is formed
Messenger RNA Ribosomal RNA Transfer RNA Bringamino acids toribosome Carryinstructions Combine with proteins tRNA mRNA rRNA DNA Ribosome Ribosomes RNA Concept Map Section 12-3 RNA can be also called which functions to also called which functions to also called which functions to from to to make up
Protein structure and composition • proteins are polymers • made up of long chains of amino acids • 20 different amino acids • proteins fold into specific shapes based on the sequence of amino acids