Lecture 8

Question 1

Flow of genetic info in eukaryotes

Answer 1

• each gene transcribed individually into a single mRNA
• replication and transcription occur in nucleaus
• RNAs must be exported out of nucleus for translation

Question 2

Flow of genetic info in prokaryotes

Answer 2

• multiple genes may be transcribed in one mRNA

- coupled transcription and translation occur = more proteins

Question 3

Termination of RNA synthesis is covered by…

Answer 3

a specific DNA sequence

Question 4

intrinsic terminators

Answer 4

transcription is terminated w/o any additional factors

Question 5

Rho-dependent termination

Answer 5

Rho protein recognizes specific DNA (RNA) sequences and causes a pause in RNA pol.

Question 6

unit of transcription

Answer 6

unit of chromosome bounded by sites where transcription of DNA to RNA is initiated and terminated

Question 7

examples of RNA that a re not translated

Answer 7

rRNA, tRNA

Question 8

typesof rRNA

Answer 8

16S, 23S, 5S

Question 9

rRNA and tRNA are very..

Answer 9

stable

Question 10

tRNA cotranscribes with…..

Answer 10

rRNA or other tRNA

Question 11

mRNAs have…

Answer 11

short half lives (few mins)

Question 12

Prokaryotes often have genes clustered together and these genes….

Answer 12

are transcribed all at once as a single mRNA

Question 13

polycistronic mRNA

Answer 13

an mRNA encoding a group of cotranscribed genes

Question 14

operon

Answer 14

a group of related genes cotranscribed on a polycistrochaperonsnic mRNA
-allows for expression of multiple genes to be coordinated

Question 15

chaperones

Answer 15

assist other proteins for proper folding or for assembly into larger complexes

Question 16

signal sequences

Answer 16

found at the beginning of on proteins requiring transport from cell and prevent protein from completely folding

Question 17

signal sequences signal…

Answer 17

the cell’s secretory system (Sec system)

Question 18

The Tat system

Answer 18

secretion of folded proteins

Question 19

tat protein export system

Answer 19

different from Sec export proteins that fold in cytoplasm

Question 20

Types i to VI Secretion Systems

Answer 20

-large complex of proteins that form channels through membranes

Question 21

Types II and V Secretion Systems

Answer 21

depend on Sec or Tat

Question 22

Tyes I, III, IV, and VI Secretion Systems

Answer 22

do not require Sec or Tat