DNA to Protein

Question 1

which carbon always has an OH group?

Answer 1

3’

Question 2

Which carbon always has the phosphate group?

Answer 2

5’

Question 3

which carbon makes the difference between RNA and DNA?

Answer 3

2’

Question 4

What is a nucleoside made up of?

Answer 4

sugar + base

Question 5

What is a nucleotide made up of?

Answer 5

nucleoside + phosphate(s)

Question 6

What is the difference between RNA and DNA building blocks and give examples of some

Answer 6

RNA building block don’t have d e.g ATP GTP, DNA building block are like dATP, dGTP

Question 7

What is polymerisation?

Answer 7

phosphodiester bond is formed between a free 3’ OH group and a 5’ triphosphate

Question 8

Only which end are new nucleic acids added on?

Answer 8

3’ carbon end

Question 9

What is the catalyst for DNA replication?

Answer 9

DNA polymerase

Question 10

What is required to start DNA rep?

Answer 10

RNA primer

Question 11

Leading strand has what carbon free?

Answer 11

3’

Question 12

Describe lagging strand

Answer 12

5’ carbon free so replicated in fragments with Okazaki fragments being produced

Question 13

What unwinds DNA?

Answer 13

helicase

Question 14

What are 3 main forms of RNA and describe what they do.

Answer 14

rRNA, tRNA, mRNA. rRNA combines with protein to form ribosome. tRNA carries amino acid chain to be incorporated into protein. mRNA carries genetic info for protein synthesis

Question 15

the specific amino acid is attached to which end of tRNA?

Answer 15

3’

Question 16

How many RNA polymerases do eukaryotes and prokaryotes have?

Answer 16

eukaryotes have 3 prokaryotes have 1

Question 17

Describe the steps of transcription

Answer 17

RNA Polymerase binds, DNA chain unwinds. RNA initiation (selection first nucleotide) and elongation. Termination

Question 18

TATA box is present where?

Answer 18

on RNA 25 nucleotides before transcription starts

Question 19

What does TBP do?

Answer 19

recognises TATA box and kinks DNA

Question 20

What 2 factors extend transcript on own

Answer 20

TFIIF and POL II

Question 21

What direction is RNA synthesised?

Answer 21

5’ to 3’

Question 22

Describe termination

Answer 22

RNA makes stem loop structure. Enzymes cleaves RNA

Question 23

Describe 2 ways of regulating transcription

Answer 23

requires specific transcription factors and binds to DNA in presence of a promoter

Question 24

What happens to steroid receptors once activated in cytoplasm?

Answer 24

move to nucleus and bind to DNA

Question 25

What two things happen to process ends of mRNA?

Answer 25

Addition of cap on 5’ end and addition of poly(a) tail on other end

Question 26

Give 3 traits of genetic code

Answer 26

unambiguous, degenerate, universal

Question 27

What do Aminoacyl-tRNA synthetases do?

Answer 27

Bind amino acids to corresponding tRNA molecule

Question 28

how any rRNA molecules are in the ribosome?

Answer 28

4

Question 29

What two things does initiation require?

Answer 29

initiation factors and GTP for energy

Question 30

what does the elongation factor do?

Answer 30

brings next aminoacyl-tRNA to A site

Question 31

when is the EF released?

Answer 31

when GTP is hydrolysed

Question 32

what does peptidyl transferase do?

Answer 32

catalyses peptide bond formation between amino acid at P and A sites

Question 33

when does termination occur?

Answer 33

when stop codon enters A site. Release factor then binds

Question 34

what does a nonsense mutation result in?

Answer 34

a new termination codon

Question 35

what is a frameshift mutation?

Answer 35

addition or deletion in one or two base pairs

Question 36

Free ribosomes make proteins destined for?

Answer 36

nucleus, mitochondria

Question 37

Ribosomes bound to nucleus make proteins for?

Answer 37

Golgi, ER