Which is released from the pituitary gland, can potentially increase the height and weight of an individual to gigantic proportions, especially if administered during childhood and adolescence.

Growth hormone

Explanation:

The growth hormone is released by somatotropic cells of the anterior pituitary gland. The growth hormone is an anabolic hormone and metabolic, tissue building and growth-promoting effects on the body. It stimulates the mobilization of fats, increases the blood levels of fatty acids to be used as flues for ATP production. It reduces glucose uptake and triggers glycogen breakdown.

In response to growth hormone, insulin-like growth factors are produced by the liver, skeletal muscle, bone, and other tissues which in turn facilitate growth by cell division, stimulated formation of collagen and deposition of bone matrix.

The growth hormone triggers cell division and cell enlargement, stimulates the growth of long bones by affecting the epiphyseal plate. It also stimulates the skeletal muscles to increase muscle mass. The overall effect is somatic growth. Its hypersecretion during childhood and adolescence can cause gigantism since the active epiphyseal plates promote excess bone growth.

answer: substrate concentration. enzymes work best when there is a high enough substrate concentration for the reaction they catalyse.