How are 'sticky ends' formed on a DNA strand? Why are they so called?
(i) Restriction enzymes cut the strand of DNA a little away from the centre of the palindrome sites, but between the same two bases on the opposite strands leave single stranded portions at the ends. These are overhanging stretches called sticky ends on each strand.
(ii) These are named as sticky ends because they form hydrogen bonds with their complementary cut counterparts. This stickiness of the ends facilitates the action of the enzyme DNA ligase.