DNA + RNA Structure Flashcards
Describe DNA
Base pairs
Ribose sugars
Phosphate
Double stranded
Describe RNA
Base pairs
Ribose sugar
Phosphate
Single stranded
What are the different types of RNA?
mRNA
tRNA
rRNA
What are both DNA + RNA?
Polymers made up from repeating monomer units known as nucleotides
What are nucleotides made from?
3 different units
= sugar
= base
= phosphate group
What are the 2 types of bases?
Purine base (imidazole + pyrimidine) Pyrimidine base (pyrimidine)
What are the purine bases?
6-aminopurine derivative = adenine
2-amino-6-hydroxypurine derivative = guanine
What is tautomerism?
Form of constitutional isomerism
= intramolecular formal migration of H atom
What is common tautomerism?
Keto-enol tautomerism
What happens to guanine in tautomerism?
H is removed from N-H + added to O = O-H
What happens to adenine in tautomerism?
H is removed from N-H + added to N = NH2
What are the pyrimidine bases?
Uracil
Cytosine
Thymine
What is thymine?
DNA only
What is uracil?
RNA only
What is the difference between DNA + RNA sugars?
DNA = deoxyribose RNA = ribose
Describe ribose- 2’OH group
RNA chemically more reactive than DNA
= 2’OH = nucleophile
What are both DNA + RNA joined together by?
Phosphodiester bonds
What is primary structure?
Linear sequence of nucleotides
What is secondary structure?
Base pairing of complementary nucleotides
DNA= double stranded
RNA = single stranded
What is base stacking?
Hydrophobic interactions + Van Der Waal forces
What are DNA helices stabilised?
Stacking of base pairs
What are the different type of DNA?
B DNA
A DNA
Z DNA
How many H bonds does A-T have?
2
How many H bonds does G-C have?
3
Why is it a helix?
Hydrophilic of nucleotide face outwards
Hydrophobic bases form middle
Space between base pairs then twist to stop PO4 3- repulsion
Why do the spaces between bases collapse?
Stop H2O from getting in
