lecture 3- Dna, Proteins and genes

Question 1

what is a bacteriophage

Answer 1

• virus that attacks bacteria

- comprise DNA and protein, the same materials as chromosomes

Question 2

describe the reproduction of bacteriophages

Answer 2

1) virus lands on bacteria
2) dna injected through tail into bacteria
3) new portions of new viruses produced ready to be assembled
4) new virus is assemble and cell bursts to release these new cells to attack future bacterial cells.

Question 3

how many rings does each base have?

Answer 3

adenine = double ring
guanine= double ring
cytosine= single ring
thymine= single ring

Question 4

sugar is attached to what in two adjacent nucleotides

Answer 4

phosphate group

Question 5

describe the Watson crick model of DNA

Answer 5

1) 2 stands of nucleotides arranged in double helix
2) connected by weak strands between bases
3) A binds to T
4) C binds to G

Question 6

what does the Helices enzyme do during replication of DNA?

Answer 6

unravels stands and keeps them separate

Question 7

what does the DNA polymerase enzyme do during replication of DNA?

Answer 7

joins nucleotides together to make a new stand of DNA

Question 8

what does the DNA Ligase enzyme do during replication of DNA?

Answer 8

joins segments of DNA

Question 9

in what direction is DNA replicated?

Answer 9

one side is synthesised towards point of unravelling, new nucleotides are being added sequently

And opposite side is synthesised in the opposite direction , segments of DNA made from nucleotides are added at the end by ligase

Question 10

name 5 types of proteins, examples and locations for each one.

Answer 10

1) structural= crystallins=lens
2) transport= haemoglobin=BVs
3) protective= antibodies= blood
4) receptor=rhodopsin=rods/cones
5) contractile=actin/myosin=eye muscles