Chapter 19, Problem 19.75QP

(a)

Interpretation Introduction

Interpretation:

The reason behind the importance of cells to regulate the level of enzyme activity has to be given.

Concept Introduction:

All physiological biochemical reactions work most efficiently under $\text{pH}$ of 7. This is often referred to as the optimum $\text{pH}$. The rate of the enzyme-catalyzed reaction is found to be maximum near this optimum $\text{pH}$ value.

To ensure that the cell does not lose its entire energy cell takes to different mechanisms of enzyme regulation. All of these mechanisms serve to conserve the cellular energy of the cell.

(b)

Interpretation Introduction

Interpretation:

The reason behind the careful control of the synthesis of digestive enzymes has to be given.

Concept Introduction:

Enzyme regulation is important because it prevents the wastage of energy in the case of the absence of substrate molecules or when the excess of the product has been synthesized.

For example, bacteria save their energy as they only produce the enzymes in response to a specific sugar substrate. They do not produce enzymes unnecessarily to break all the sugars. This is achieved via various mechanisms of regulation of the enzyme’s activity such a feedback inhibition via allosteric enzymes or via the creation of proenzyme. The latter is an inactive form of an enzyme that regulates the activity via proteolysis.