2.1.3

Question 1

differences between RNA and DNA

Answer 1

RNA smaller and single strand, has ribose rather than deoxyribose so extra O on C2 and uracil rather than thymine

Question 2

purines and definition (2)

Answer 2

double carbon ring
Adenine
Guanine

Question 3

pyrimidine

Answer 3

single carbon ring
Cytosine
Thymine
Uracil

Question 4

base pairings and bonds

Answer 4

AT/ AU, 2 hydrogen bonds
CG, 3 hydrogen bonds

Question 5

how do nucleotides join

Answer 5

condensation reaction
3,5 phosphodiester bonds
DNA polymerase o.e.

Question 6

ATP synthesis

Answer 6

condensation/ phosphorylation
enzyme ATP synthase in aerobic (mitochondria) and less in anaerobic (cytoplasm)

Question 7

ATP breakdown

Answer 7

hydrolysis
enzyme ATP hydrolase breaks phosphate from tri into di and mono to release energy

Question 8

ATP properties

Answer 8

small, water soluble, cant be stored well, can be recycled back into ATP easily

Question 9

ATP components

Answer 9

three phosphate groups and adenosine (ribose and adenine)

Question 10

DNA extraction

Answer 10

grind - cell wall
detergent - csm
salt - H in DNA/ water
protease - histones
ethanol - precipitate out DNA

Question 11

DNA description

Answer 11

two antiparallel strands of nucleotides coiled into a double helix

Question 12

DNA replication enzymes

Answer 12

DNA helicase breaks H bonds
DNA polymerase joins nucleotides, 3-5 phosphodiester
DNA ligase joins adjacent nucleotides

Question 13

semi-conservative replication overview

Answer 13

DNA breaks by helicase
free and activated nucleotides attach
joined by polymerase
original strands conserved

Question 14

continuous replication

Answer 14

leading strand, makes 5-3 towards replication fork

Question 15

discontinuous replication

Answer 15

lagging strand, makes 3-5 away from fork so has to reattach forming okazaki/ DNA fragments which are joined by DNA ligase

Question 16

genetic code properties

Answer 16

degenerate (multiple codons can code for 1 a.a. as mutations)
non-overlapping (read once, continuously)
universal (AUG is always start)
triplet (3 base 1 a.a.)

Question 17

start and stop codon

Answer 17

AUG/ Methionine for start
3 kinds for stop

Question 18

transcription

Answer 18

initiation - RNA polymerase attaches to recognition sites
elongation - free & activated off template/ antisense 5-3
termination - stop codon means detach, mRNA made

Question 19

translation

Answer 19

mRNA to ribosome (ft. rRNA)
tRNA with a.a. anticodon to codon and repeat until stop

Question 20

what is genetic code

Answer 20

set of rules for translation/ protein synthesis