B.5 Feedback Systems

Metabolic pathways

Allow cells to conduct reactions in small steps without disrupting other cellular activities.

Cofactors

Accessory molecules that assist in metabolic reactions.

Regulation of reaction rate

The capability of metabolic pathways to adjust the speed of reactions as necessary.

Cruise control analogy

A comparison of metabolic regulation to vehicle cruise control where speeds are adjusted based on needs.

CO2 regulation in plasma

The maintenance of carbon dioxide levels in plasma through respiration orchestrated by the medulla oblongata.

Acidosis

A condition resulting from persistent lowered blood pH.

Acidemia

A lethal condition resulting from failed pH maintenance mechanisms.

Alkalosis

A higher than normal blood pH, which may indicate kidney failure.

Negative feedback

Occurs when the product concentration inhibits the initial step in its metabolic pathway.

Positive feedback

Increases the rate of a physiological process, reinforcing further change rather than maintaining homeostasis.

Childbirth and oxytocin

The process where oxytocin promotes uterine contractions to facilitate birth, exemplifying positive feedback.

Labour

The muscle contractions caused by oxytocin during childbirth.

Homeostasis

The maintenance of a stable internal environment within an organism.