DNA + RNA Flashcards
(13 cards)
What does DNA stands for
deoxyribonucleic acid and it is used to store genetic info for repair and reproduction
what does RNA stand for
ribonucleic acid transfers genetic info from DNA to ribosomes
what is a nucleotide
type of biological molecule
what is a nucleotide made of
a pentose sugar
a nitrogenous base
a phosphate group
describe the nucleotide in DNA
pentose sugar is deoxyribose
4 bases are adenine, thymine, cytosine and guanine
describe the nucleotide of RNA
pentose sugar is ribose
4 bases are adenine cytosine guanine and uracil replaced thymine
what are a group of nucleotides called and how do they join
polynucleotide
condensation reactions
what type of bond is formed between nucleotides
ester and phophodiester is whole thing
describe the structure of DNA
Double helix
bases joined by hydrogen bonds
they have complimentary bases pairs- A-T- 2 bonds
C-G 3 bonds
equal amounts of DNA bases
describe the structure of RNA
single polynucleotide chain
A-U
C-G
much shorter then DNA
describe the process of DNA replication
1) DNA helices breaks hydrogen bonds between bases- unwinds the dna to form 2 strands
2) each original acts as a template for a new strand. complimentary base pairs mean free floating DNA is attracted to exposed bases
3)condensation reaction happens to join nucleotides of new strands together- catalysed by dna polymerase to form new hydrogen bonds
4) each new strand contains one new and one original
why is DNA rep described as semiconservative
this is because it contains 1 new strand and one old
what is meselson and stahl evidence for semi-conservative
look in revision guide
