STRUCTURE OF DNA AND RNA

Question 1

What is the function of DNA

Answer 1

Hereditary molecule that passes on genetic information from generation to generation

Question 2

What is the function of nucleic acids

Answer 2

Group of information carrying molecules that are involved in protein synthesis and are essential for cellular life

Question 3

Function of RNA

Answer 3

Involved in transferring information from the DNA to the ribosomes

Question 4

Structure of both

Answer 4

Both RNA and DNA are polynucleotides made of repeated nucleotide monomers with a similar structure

Question 5

How is a double helix formed

Answer 5

Interactions between nearby DNA monomers leads to coiling in a polymer

Question 6

Why are strands described as antiparallel

Answer 6

They run in opposite directions

Question 7

What is the bond between nucleotides called

Answer 7

Phosphodiester bond

Question 8

What is complementary base pairing

Answer 8

2 polynucleotide strands can join by hydrogen bonding
A-T C-G
Equal amounts of complementary bases in the polynucleotide

Question 9

Franklin

Answer 9

Used X rays to understand the physical structure of the DNA molecule
When you shine x rays on DNA, the rays bounce off the sample creating complex patterns

Question 10

Watson and crick

Answer 10

Used ball and stick models to test ideas on possible structure of DNA
Identified helical structure in 1953

Question 11

DNA vs RNA pH stability

Answer 11

Deoxyribose sugar in DNA is less reactive bc of C-H bonds. Stable in alkaline conditions
Ribose sugar is more reactive bc of hydroxyl bonds C-OH. Not stable in alkaline conditions

Question 12

DNA vs RNA enzyme stability

Answer 12

DNA has smaller grooves which makes it harder for enzymes to ‘attackRNA has larger grooves which makes it easier to be ‘attacked’ by enzymes

Question 13

DNA vs RNA UV stability

Answer 13

DNA protected in the nucleus as it is tighly packed and DNA can be damaged by exposure to UV rays
RNA strands are continually made, broken down and reused, RNA is more resistant to damage by UV rays

Question 14

Triplet code

Answer 14

A sequence of three nucleotides on a DNA or RNA molecule codes for a specific amino acid in protein synthesis
The code is degenerate in that more than one sequence codes for each amino acid

Question 15

Origins protein coding

Answer 15

Amino acids have some attraction to RNA bases due to charges
It is thought that in early conditions this encouraged polypeptide formation however this process has evolved to be much more efficient