Question

What is feedback mechanism?

Answer 1

Feedback mechanism is a mechanism that tends to initiate (accelerate) or to inhibit (slow down) a process. Feedbacks mechanisms help regulate biochemical pathways.
(a) In negative feedback, the end product accumulates and inhibits the action of the first enzyme thereby slowing the reaction.
(b) In positive feedback, the end product stimulates an enzyme in the pathway to increase overall production.
A feedback mechanism may be observed at the level of cells, organisms, ecosystems, or the biosphere. It regulates homeostasis or balance to achieve certain range or level of optimal condition. Deviation from homeostasis could eventually lead to effects detrimental to the proper functionality and organization of a system.

An example of positive feedback loop is the onset of contractions in childbirth. When contraction begins, the hormone oxytocin is released into the body to stimulate further contractions. As for the negative feedback loop, an example is the regulation of blood glucose levels. If blood glucose levels continue to rise it may result in diabetes. In fact, there are many biologic processes that use negative feedback to maintain homeostasis or dynamic equilibrium.

[Homeostasis is the state of steady internal conditions maintained by living things. This dynamic state of equilibrium is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits]