Question

1. Describe how vertebrates maintain blood glucose homeostasis. Why is the regulation of blood glucose levels so important for the success of vertebrates?

1. Compared with squid and shrimp, vertebrates can tolerate longer periods of anaerobic activity. Explain the metabolic adaptations that make this possible.

Answer 1

Glucose homeostasis is primarily maintained by glucagon and insulin.. Insulin,a hormone released from beta cesfound in the islets of langerhans in the pancreas,lowers blood sugar, and Glucagon,released by alpha cells of pancreas , raises blood glucose level.Glucagon travels through the blood to the liver, and binds to glucagon receptors on the surface of liver cells and stimulates them to break down glycagon stored inside the cell to glucase(glycogenesis). The cells release the glucose into the bloodstream, increasing blood sugar levels.

When levels of glucose rises,insulin causes the liver to convert more glucose into glycogen (glycogenesis), and to force about body cells ,muscle and fat tissue cells,to take up glucose from the blood and hence decreasing blood sugar.

Blood glucose regulation is very important for the maintenance of the human body. Bain doesn’t have any energy storage of its own and needs a constant amount of glucose, using about 60% of total glucose used by the body at resting state. With out proper blood glucose regulation the brain and other organs could starve leading to death.

Animal survival during severe anerobic cnditionis enhanced by a variety of biochemical adaptations.Like adaptations of fermentative pathways of energy production and,the ability to sharply reduce metabolic rate and enter a hypometabolic state.