Replication/Transcription/Translation

Question 1

DNA polymerase

Answer 1

has subunits on core enzyme

Alpha, epsilon, theta

Question 2

what does alpha do on DNA Pol

Answer 2

machinery, polymerase

Question 3

what does epsilon do in DNA Pol

Answer 3

exonuclease activity (proof reading)

Question 4

what is role of theta subunit

Answer 4

activates exonuclease activity/proof reading

Question 5

DNAb

Answer 5

aka helicase

breaks H bonds of DNA and separates strand

promotes primase activity

Question 6

SSB

Answer 6

bind single stranded DNA after strands are separated by helicases

Question 7

Topoisomerase

Answer 7

separation of chromosomes upon completion of DNA replication

relieves tension

Question 8

Primase

Answer 8

synthesis of RNA primer

Question 9

Gyrase

Answer 9

relieves supercoiling of DNA produces as DNA strands, separated by hellicases

separates daughter molecules in final stages of replication

Abs target

Question 10

DnaC

Answer 10

helices loader, directs DnaB to template

Question 11

ribonuclease H (RNA-H)

Answer 11

removes RNA primers

Question 12

DNA ligase

Answer 12

seals together nicked DNA, joining fragments together

Question 13

Tus

Answer 13

terminates replication

Question 14

What part of RNA Pol factor has no catalytic activity but aids in transcription initiation?

Answer 14

sigma

Question 15

sigma factors transcription

Answer 15

initiation of transcription

binds to DNA at promotor region at -10 sequence and -35 sequence

Question 16

-35 sequence

Answer 16

RNA Pol recognition site

Question 17

-10 sequence

Answer 17

RNA Pol binding site

pribnow box

TATAAT

Question 18

what makes up the holoenzyme

Answer 18

core enzyme + sigma factor

Question 19

Rho is active in which process

Answer 19

termination of transcription

pressure on DNA/RNA hybrid that stimulates it release

Question 20

rho independent pathway

Answer 20

pausing at termination site (UA rich regions) that forms a loop structure which destabilizes UA bonds and pulls apart DNA/RNA hybrid

Question 21

rho dependent pathway

Answer 21

binding of Rho at rho entry site

travels mRNA to “catch up” with RNA Pol then grabs it when RNA Pol pauses to destabilize RNA/DNA hybrid, stimulating separation

Question 22

-10 and -35 regions are found in what region

Answer 22

promotor

Question 23

leader sequence

Answer 23

transcribed but since it is upstream of the starter, it is not translated

has shine delgarno sequence – binding of 16s

Question 24

23s catalyzes…

Answer 24

formation of peptide bond between newly synthesized proteins

Question 25

translation initiation

Answer 25

1. initator codon binds 16s rRNA in 30s subunit
2. Shine delgarno sequence is aligned with 16s rRNA
3. IF-3 binds to 30s, prevents it from binding to 50s
4. IF-2 binds to GTP, mRNA, tRNA and guides to P site of 30s
5. IF-1 binds to 30s, removes IF-3, 30s binds to 50s
6. GTP hydrolyzes, IF-1, IF-2 removed and 70s initiation complex is formed

Question 26

is RNA transcribed one at a time?

Answer 26

no, you can have multiple ribosomes transcribed/bound to rRNA

polyribosome

Question 27

what are differences between eukaryotic and prokaryotes

Answer 27

introns and exons in eukaryotes

polysystronic mRNA in prokaryotes

Question 28

polysystronic mRNA

Answer 28

prokaryotes

allows translation of a single RNA but lots of proteins produce

Question 29

stop codon

Answer 29

doesn’t code for an AA, they instead catalyze a reaction that produces water

Question 30

release factors

Answer 30

termination

cause ribosomal subunits to come apart and release

Question 31

protein splicing

Answer 31

Removal of part of polypeptide before folding

Inteins – removed portion

Externs – portions that remain in protein

some bacterial peptides, right after translation but before final folding conformation