nucleic acids

Question 1

DNA function

Answer 1

hold or store genetic information

contains the instructions for growth and development of organisms

Question 2

RNA function

Answer 2

transfer genetic code found in DNA out of the nucleus

RNA is read to make proteins in translation

Question 3

each nucleotide is formed of

Answer 3

pentose sugar - DEOXY / RIBOSE
phosphate group
nitrogenous base (eg. U C T A G )

Question 4

sugar in DNA

Answer 4

deoxyribose sugar

Question 5

sugar in RNA

Answer 5

ribose sugar

Question 6

bases in DNA

Answer 6

T A G C

Question 7

RNA bases

Answer 7

U A G C

Question 8

purines

Answer 8

adenine , guanine
double ring structure

Question 9

pyramidine

Answer 9

cytosine, thymine, uracil
single ring structure

Question 10

bonds that joins seperate nucleotides

Answer 10

phosphodiester bonds

(called this bc it consists of a phosphate group and 2 ester bonds)

Question 11

chain of alternating phosphate groups and pentose sugars is known as

Answer 11

sugar - phosphate backbone

Question 12

STRUCTURE OF DNA SMA

Question 13

Why is it called semi conservative replication

Answer 13

‘In each new dna, half is from the parent and half is from new free floating complementary bases

Question 14

Importance of retaining one original DNA strand

Answer 14

Ensures there is genetic continuity - cells with new dna inherit same genes
Important as cells are regularly changed - same role needed after being changed

Question 15

What does DNA replication occur in preparation for

Answer 15

Mitosis - replication occurs during interphase s

Question 16

Process of DNA replication
Semi conservative

Answer 16

Helices unwinds the double helix by breaking the hydrogen bonds
Each of the newly single strands acts as a template
New free flowing nucleotides join onto each single strand with complimentary base pairing -condensation reactions catalysed by DNA polymerase

Forming new hydrogen bonds

Question 17

Why does DNA polymerase only work in one direction

Answer 17

Polymerase only works from the 3 to 5 prime end
As it goes towards the split in the two template strands

Goes away from the new DNA helix

Question 18

DNA ligase

Answer 18

Joins lagging strand segments together by catalysing the formation of phosphodiester bonds

Lagging strand = short segments of the DNA have not joined together

Question 19

Watson and crick semi conservative replication experiment

Answer 19

DNA contains nitrogen in bases]
Bacteria is grown in a broth with N15
DNA then takes up this N15

A sample of this DNA is spun in a centrifuge -
Heavy DNA appears at the bottom of the tube

Added to a broth containing N14, DNA was extracted and spun in a centrifuge now as half of the DNA was N14 and HAlf was N15 there were two lines , one heavier , one lighter