Lab 8

Question 1

DNA ligation

Answer 1

covalent joining of DNA molecules and catalyzed by the enzyme DNA ligase

Question 2

DNA ligase

Answer 2

a ligase that can link together two DNA strands that have a single-strand break

Question 3

T4 DNA ligase

Answer 3

catalyzes the formation of a phosphodiester bond between 5’ phosphate and 3’ hydroxyl termini

join blunt end and cohesive end termini

repair single stranded nicks

Question 4

ligation reactions require…

Answer 4

two or more fragments of DNA

a buffer that contains ATP

T4 DNA ligase

Question 5

Competent cells

Answer 5

bacterial cells that take up the foreign DNA from the surroundings by the process of transformation

Question 6

Transformation

Answer 6

the process by which an organism acquires exogenous DNA

Question 7

How to set up a ligation reaction

Question 8

Key experimental conditions for a transformation

Answer 8

incubate on ice for 30 minutes

heat shock at 42 degrees C for 45 seconds

place back on ice for 2 minutes

plate incubates upside down in 37 degrees C incubator overnight

Question 9

T4 DNA ligation buffer

Answer 9

assures optimal activity of the enzyme