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Physiology: Fat Cell Responses, Blood Oxygen, Insulin Levels

Give detailed paragraph or more explanation to all questions:
1) A fat cell responds to the presence of the harmone epinephrine by increasing cytosolic cyclic AMP Production, which leads to the catabolism of both glycogen and fat; what is the best explanation for this phenomenon?
2) After spending several days at a high altitude, where oxgen pressure is low, a person will begin to produce more red blood cells, which enhances the ability of his/her blood to carry oxygen to the tissues. Which control mechanism of the body best describes this response? Explain?
3) The harmone insulin enhances the transport of glucose into most of the body's cells. Its secretion is controlled by a negative feed-back system between the concentration of glucose in the blood and and cells that secrete insulin. Is it because a decrease in blood glucose concentration will stimulate insulin secretion, which will in turn lower the blood glucose concentration still further. Explain your answer?

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1. Cyclic AMP (cAMP)induces lipolysis in fat cells. One possible mechanism is the stimulation of hormone-sensitive lipase (HSL) activity. cAMP induces HSL translocation from the cytosol to the lipid droplets in fat cells. Indeed, current research suggests that the critical event in lipolytic activation of fat cells induced by cAMP is not an increase in the catalytic activity of HSL but translocation of HSL to its substrate on the surfaces of lipid droplets in fat cells. Stored fat is mobilized by its hydrolysis to free fatty acids (FFA) and glycerol. The first step in this process is regulated by a variety of hormones, such as norepinephrine, epinephrine, and adrenocorticotropic hormone (ACTH). The mechanisms of action of these lipolytic hormones are believed to be mediated by the cAMP cascade. Lipolytic ...

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