Question

How many ATP molecules must be hydrolyzed by the proteasome for the digestion of a protein that has been tagged for degradation with a polyubiquitin chain?

a) None; the digestion does not require ATP hydrolysis and is exergonic
b) 1
c) 2
d) 10
e) many; the number depends on the specific protein

Answer 1

The degradation of a protein by the proteasome requires the hydrolysis of many ATP molecules, and the number depends on the protein being degraded.

Step-by-step explanation:

The digestion of a protein that has been tagged for degradation with a polyubiquitin chain by the proteasome requires the hydrolysis of multiple ATP molecules. This process involves several steps where ATP is used to fuel the binding of ubiquitin to the target protein and subsequently power the unfolding and translocation of the target protein into the proteasome core. The number of ATP molecules hydrolyzed is not fixed and depends on the specific protein being degraded.

Therefore, the answer to the question is 'e) many; the number depends on the specific protein'.