Question

How many hydrogen bonds exist between this DNA strand and its complementary strand? 5'- CATAGGA- 3'

Answer 1

There will be 17 hydrogen bonds between the given strand and its complementary strand.

Explainatin:

A has T in its complimentary strand

G has C in its complimentary strand

C has G in its complimentary strand.

T has A in its complimentary strand

If the sequence of strand is 5'-CATAGGA-3', then its complimentary strand is 3'-GTATCCT-5'.

There will be three hydrogen bonds between C and G bases.

There will be two hydrogen bonds between A and T bases.

The figure given below shows the hydrogen bonds between the strands in question.

You will also find pairing between bases. Dotted lines are hydrogen bonds.

CATAGGA GTATCCT H-N N-HO 3 JN-H.... N3 6 ..H-N3 N-H O Guanine (G) Cytosine (C) Adenine (A) Thymine (T)