Question

Which would have the highest melting temperature?
a. 5'-AATTCGAAT-3'
b. 5'-ACGGCTACG-3'

Answer 1

Option (b).

Step-by-step explanation:

Melting temperature may be defined as the temperature at which the DNA strand melts. The melting temperature depends on the Guanine and cytosine content of the DNA.

The thymine binds with Adenine with two hydrogen bonds whereas cytosine binds with guanine with three hydrogen bonds. More energy is required to break the guanine cytosine bonds and they have high temperature. The second strand 5'-ACGGCTACG-3' contains more GC content and hence have high melting temperature.

Thus, the correct answer is option (b).