Chapter 3 Flashcards
What is the process that converts DNA into RNA?
Transcription
What is the process that converts RNA into proteins?
Translation
What is the difference between a nucleotide and a nucleoside?
A nucleoside does not contain a phosphate group (only sugar and base)
What is a nucleotide made up of?
Sugar, nitrogenous base, phosphate
What is the difference between Ribose and Deoxyribose?
Ribose has a 2’ OH – Deoxyribose only has a 2’ H’s
What is more stable: DNA or RNA? Why?
DNA; the 2’ OH on RNA makes it much more unstable than DNA that only has 2’ H’s
List the pyrimidines:
Cytosine
Uracil
Thymine
List the purines:
Adenine
Guanine
What is the structural difference between purines and pyrimidines?
Pyrimidines are a single-ring, purines are a double-ring
Describe Adenine:
Double nitrogenous ring with a primary amine on carbon 6
Describe Guanine:
A double nitrogenous ring with a primary amine on carbon 2 and a carbonyl on carbon 6 that has caused the double bond to be removed and Nitrogen 1 to be protonated
Describe Cytosine:
Single nitrogenous ring with a primary amine on carbon 4 and a carbonyl on carbon 2 (losing the double bond with nitrogen 1)
Describe Uracil:
Single nitrogenous ring with a carbonyl on carbon 2 and 4, and a protonated nitrogen 3 between them
Describe Thymine:
Single nitrogenous ring with a carbonyl on carbon 2 and 4, a protonated nitrogen 3, and a methyl on carbon 5
**Uracil with a methyl
How many hydrogen bonds form between Adenine and Thymine?
2 hydrogen bonds
How many hydrogen bonds form between Guanine and Cytosine?
3 hydrogen bonds
What tautomer dominates for the nitrogenous bases?
Keto
Why is ATP to ADP a spontaneous reaction?
Losses a larger leaving group
ATP has more limited resonance
What supplies chemical energy?
Phosphoanhydride bonds
What does ATP supply energy for?
Metabolism
What does GTP supply energy for?
Protein synthesis
What does CTP supply energy for?
Lipid synthesis
What does UTP supply energy for?
Carbohydrate metabolism
How are nucleic acids read and put together?
5’ –> 3’
What is the structure of DNA?
Antiparallel double helix
What type of helix is DNA?
Right-handed
What is the diameter of DNA?
2 nm
How does DNA replicate?
Semi-conservative
What prevents tRNA hydrolysis?
Cloverlike structure from 3 hairpin loops
What bond holds together protein chains (amino acids)?
Peptide bonds
How are new amino acids added to an existing chain in a ribosome?
The new amino acid NH3 binds to the existing carboxylic acid
What is the function of restriction endonuclease?
Cleave DNA at specific sites
What DNA technique creates sticky and blunt ends? What is the difference between the two?
Restriction endonuclease
Sticky ends have an overhang, blunt ends are flat
What is the function of gel electrophoresis?
Separate DNA by size
Explain how gel electrophoresis works:
DNA is loaded into a gel and moves toward the positively charged electrode – smaller segments moving faster
What charge does DNA have? Why?
Negative
Phosphate group
What is the function of Sanger sequencing?
Sequence the specific base pairs from a strand of DNA
How does Sanger sequencing work?
Some normal nucleic acids and some fluorescing ones are added with a template plus primer; the nucleic acids are added and stop when they get a fluorescing one which creates different sizes that can be read to tell us the specific amino acid sequence
