In metabolic pathways, what typically happens when an end product accumulates?

In metabolic pathways, an accumulation of an end product typically leads to inhibition of the pathway. This phenomenon is known as feedback inhibition, where the end product of a metabolic process serves as a regulatory signal that reduces the activity of enzymes involved in the pathway. This mechanism is crucial for maintaining homeostasis within the cell, preventing the overproduction of certain metabolites and ensuring that resources are used efficiently.

When the end product builds up, it binds to an allosteric site on one of the enzymes involved in the pathway (often an early or key enzyme), changing its shape and function. This can slow down or halt the production of additional end product, allowing the cell to adjust its metabolism based on current needs. Thus, when the pathway is inhibited due to an excess of the end product, it can redirect resources toward other metabolic processes that may be necessary for the cell's functions under current conditions.