Question

During genetic engineering, how do Restriction enzymes know what base pairs to act on?

A. Ligase bonds it to the correct spot.
B. It recognizes the sticky ends
C.They don't, the scientist must target it manually
D.They bond to the Recognition site

Answer 1

The correct/closest option is b

Step-by-step explanation:

Restriction enzymes are enzymes (endonucleases) that cut short DNA strands at specific sites. Hence, each restriction enzyme has it's own specific site (between two bases) it cuts at. There are two types of end that can be produced by this cut; the blunt end and the sticky end.

A restriction enzyme recognizes (palindromic sequence) and cut in it's own specific end.

For example, if a restriction enzyme cuts between a guanine (G) and an adenine (A), and it cuts a palindromic double stranded DNA in the manner below, it produces a sticky end.

G║AATTC

CTTAA║G

And if a restriction enzyme cuts between guanine (G) and cytosine (C) in the manner below, it produces a blunt end.

GGG║CCC

CCC║GGG

Hence, from the question, restriction enzymes (although chosen by the scientist based on desired sequence to be cut) recognize the sticky or blunt ends itself.