plasmids

Question 1

what is a plasmid?

Answer 1

small, circular, extra-chromosomal DNA which replicates independently of host chromosomal DNA

Question 2

not all plasmids are ______

Answer 2

circular

Question 3

How are plasmids named?

Answer 3

P- plasmid
initial of the person
numbers identifying construction

Question 4

Depending on there size plasmids can encode a few or hundred of different _______?

Answer 4

Proteins

Question 5

Purifying plasmids is based on the?

Answer 5

structure of the plasmids

Question 6

what is a replicon?

Answer 6

DNA molecules that can replicates autonomously in the cell (plasmids, phages DNA and chromosomes

Question 7

Origin of replication for plasmids?

Answer 7

oriV

Question 8

The ori region determines the _____ _____ ______ ?

Answer 8

mechanism of replication

Question 9

Types of Plasmid replication? (2 types)

Answer 9

Theta replication & Rolling circle

Question 10

Theta replication?

Answer 10

Replication begin by opening the two strand of DNA at ori region, creating a structure that looks like the Greek letter 

Question 11

Unidirectional replication

Answer 11

Replication terminates when the replication fork gets back to the origin

Question 12

Bidirectional

Answer 12

Replication terminates when the replication forks meet somewhere on the DNA molecule opposite the origin

Question 13

Plasmids that replicate using rolling circle are called?

Answer 13

RC plasmids

Question 14

Rolling circle occurs in two stages?

Answer 14

1. Replicated and form double and single strand circular plasmid
2. The complementary strand is synthesized on the single-stranded DNA to make another double-stranded DNA

Question 15

FUNCTIONS OF THE Ori REGIONS (4)

Answer 15

Host range
Regulation of copy number
incompatibility
Plasmid replication control mechanism

Question 16

Regulation of copy number

Answer 16

Relaxed plasmid, molecules which inhibited a plasmid replication when the number reach certain level – mechanism present in high copy plasmids

Question 17

Incompatibility

Answer 17

Plasmid incompatibility is when plasmids can not coexist, and one or the other will be lost at a higher than normal rate when the cells divided

Question 18

ColE1 plasmid do not require a ?

Answer 18

plasmid-encode protein to initiate replication at their oriV, only an RNA primer synthesized from the plasmid

Question 19

Most of the plasmids require a plasmid-encoded protein called _____?

Answer 19

Rep

Question 20

The plasmid-encoded protein Rep does what?

Answer 20

It separate the strand of DNA at oriV region
Is very specific, Only bind to oriV from the same plasmid
The synthesis of Rep partially control the copy number of the plasmid

Question 21

Their oriV region contains several repeats of a certain set of DNA bases called?

Answer 21

iteron sequence

Question 22

The iteron sequence has __ to __ bp

Answer 22

17 to 22