Question

1. Explain the difference between an exonuclease and an endonuclease.

2. Draw the substrates and products for the reactions of calf intestinal phosphatase (CIP) and tobacco acid pyrophosphatase (TAP). In particular the products of the action of TAP on the 5' mRNA Cap. (Go ahead and look this up if you need to - might be in an online catalog or a paper). Which phosphoanhydride bond in the Cap structure is cleaved by TAP? Choices are the beta-gamma bond, or the alpha-beta bond.

Answer 1