Cell Division -DNA

Question 1

Chargaff’s rules

Answer 1

A=T
G=C
A+G = T+C

Question 2

How can drugs target dna directly

Answer 2

Electrostatic interaction with surface phosphates
Alkylation
Minor groove binding intercalating (compound binds to ring of ladder)
DNA cleavage (reactive specked that cuts dna)

Question 3

Purine

Answer 3

A, G
Double

Question 4

Pyrimidine

Answer 4

C, T
Single

Question 5

What direction is each dna strand

Answer 5

5’ to 3’

Question 6

What is nucleoside

Answer 6

Sugar+ nucleobase

Question 7

How many hydrogen bonds in C,G

Answer 7

3

Question 8

how many hydrogen bonds in AT

Answer 8

2

Question 9

What is major and minor groove

Answer 9

Distance between two sections of the helical dna

Question 10

How is dna structure stabilised

Answer 10

Pi-pi interactions
Electrostatic forces from the negative charges
Stacking

Question 11

What is major groove motif

Answer 11

If H/O/N is attached to a donor/ acceptor

Question 12

DNA tertiary structure

Answer 12

Histone
Nucleosome
Chromatin
Chromosomes

Question 13

Action of topoisomerase

Answer 13

Cuts dna to relieve the tension caused by unravelling
Pulls chains apart so dna can pass

Question 14

RNA involved in protein synthesis

Answer 14

mRNA
tRNA
rRNA

Question 15

semi conservative replication

Answer 15

Separates into two strands

Question 16

DNA synthesis

Answer 16

Needs a primer
Needs dna polymerases to proof read and remove incorrectly matching nucleotides

Question 17

What is the leading strand in the replication fork

Answer 17

New strand made as a continuous piece

Question 18

What is the lagging strand in the replication fork

Answer 18

Okazaki fragments in small pieces
Primer can’t continuously cut the dna so goes by small pieces