Regulation of Cellular Respiration

Free Response

How does citrate from the citric acid cycle affect glycolysis?

Hint:

Citrate can inhibit phosphofructokinase by feedback regulation.

Why might negative feedback mechanisms be more common than positive feedback mechanisms in living cells?

Hint:

Negative feedback mechanisms actually control a process; it can turn it off, whereas positive feedback accelerates the process, allowing the cell no control over it. Negative feedback naturally maintains homeostasis, whereas positive feedback drives the system away from equilibrium.