dna replication, beginning of chapter 9 (dna to protein) - (lecture 9)

Question 1

okazaki fragment

Answer 1

the little backwards bits during dna replication where it has to keep going up and returning to the point it started before

Question 2

replication fork

Answer 2

the branching prongs that form when helicase separates the strands

Question 3

explain dna replication with enzymes and what each enzyme’s role is

Answer 3

• topoisomerase: untwists, travels upwards
• helicase: follows; separates (triangle) (replication fork)
• dna polymerase: needs primers, can only run 5’ to 3’
• dna ligase: joins the okazaki fragments

Question 4

explain transcription with enzymes and what each enzyme’s role is

Answer 4

• rna polymerase: needs a promoter to

Question 5

explain translation with all processes involved:

Answer 5

• rna polymerase must first bind to a promoter (sequence in dna)
• explain the guanine cap

Question 6

name the three types of rna

Answer 6

messenger, transfer, and ribosomal

Question 7

the process by which dna nucleotides are used to create rna nucleotides

Answer 7

transcription

Question 8

the process by which rna nucleotides are used to make proteins
- first forms polypeptide chains, which fold to form proteins

Answer 8

translation

Question 9

where does transcription occur?

Answer 9

the nucleus
(note that the rna then moves into the cytoplasm)

Question 10

where does translation occur?

Answer 10

the cytoplasm

Question 11

rna that carries protein building instructions

Answer 11

messenger rna

Question 12

rna that makes up ribosomes

Answer 12

ribosomal rna

Question 13

rna that delivers amino acids to the protein chain

Answer 13

transfer rna

Question 14

how is dna replication similar to transcription (rna synthesis?)

Answer 14

they both add nucleotides from the 5’ to 3’ direction

Question 15

how is dna replication unlike transcription (rna synthesis?)

Answer 15

• only small portions are the template
• rna polymerase is the catalyst, not dna polymerase
• the product is single stranded
• rna has 2 oh groups, one on the 2’ and 3’, and dna only has a h on the 2’ carbon

Question 16

what is the small sequence of dna above a a gene that signals it as a starting place for a gene?

Answer 16

the promoter

Question 17

name the four nucleic acids in dna

Answer 17

a,t,c,g

Question 18

name the four nucleic acids in rna

Answer 18

a,u,c,g

Question 19

which codon is always at the start

Answer 19

aug

Question 20

what does aug stand for

Answer 20

methyanine

Question 21

there are ___ different stop codons

Answer 21

3

Question 22

explain the use of poly-a tails

Answer 22

they are used to determine the amount of times a piece of rna should be synthesized because a certain enzyme starts destroying it when the reaction begins (longer = more times it can replicate)

Question 23

mrna

Answer 23

mrna is just like regular rna but it has the introns “snipped out”

Question 24

rrna

Answer 24

carries protein-building intructions from the nucleus into the cytoplasm

Question 25

rrna

Answer 25

a major component of ribosomes

Question 26

trna

Answer 26

delivers amino acids to the ribosomes in the cytoplasm

Question 27

tell me about the chart thingy mabobber

Answer 27

• 64 codons
• 3 stop
• 61 amino acid places, 20 amino acids