A1.2 Nucleic Acids Flashcards
structure, RNA vs DNA, base pairs, anti-parallelism, hershey-chase, chargaff
what is a chromosome and how many are in most human cells?
polymer of nucleosomes; 46
what do DNA and RNA stand for?
deoxyribonucleic acid and ribonucleic acid
how is DNA evidence of common ancestry?
universal genetic material, with mutations influencing evolution
define gene
a sequence of nucleotides
what defines cell identity and function?
the proteins it can synthesize
describe the structure of a nucleotide
1 phosphate group, 1 pentose sugar, and 1 nitrogenous base connected by covalent bonds
what nitrogenous bases are in DNA and RNA?
adenine, thymine (uracil in RNA), cytosine, guanine
how many different nucleotides are in DNA and RNA?
8; 4 in DNA have deoxyribose sugar, 4 in RNA have ribose and uracil instead of thymine
draw a section of DNA with the four different nucleotides
pentagonal sugar, circle phosphate connected to 5’ carbon, rectangular base connected to 1’, 3’ connected to phosphate of next nucleotide, strands antiparallel, left side 5’-3’, right 3’-5’, carbons labelled, thymine bonded to adenine with 2 hydrogen bonds, cytosine to guanine with 3, solid lines for covalent bonds, dotted for hydrogen bonds
what are the differences between DNA and RNA?
DNA:
* deoxyribose
* double helix shape
* two chains
* thymine
* permanent genetic code
RNA:
* ribose
* various shapes
* one chain
* uracil
* no permanent genetic code
draw deoxyribose
2 C’s bonded to OH and H, 2’ C bonded to 2 H’s, top O, 4’ C bonded to HOC5’H2
draw ribose
3 C’s bonded to OH and H, top O, pentagon, 4’ C bonded to HOC5’H2
what is mRNA?
messenger RNA; RNA copy of DNA sequence, relays genetic information
what is tRNA?
transfer RNA; ensures correct order of amino acids
what is rRNA?
ribosomal RNA; synthesizes ribosomes