Define glycogenesis, gluconeogenesis, and lipogenesis. Which is (are) likely to be occurring (a) shortly after a carbohydrate-rich meal, (b) just before waking up in the morning?
Glycogenesis is the process by which glucose molecules are combined in long chains to form glycogen. Gluconeogenesis is the formation of new sugar from noncarbohydrate molecules. Lipogenesis is the term for triglyceride synthesis.
a.) Glycogenesis (and perhaps lipogenesis) is likely to occur after a carbohydrate-rich meal.
b.) Gluconeogenesis is likely to occur just before waking up in the morning. (pp. 929-930)
Distinguish between the role of HDLs and that of LDLs.
HDLs function to transport cholesterol from the peripheral tissues to the liver. LDLs transport cholesterol to the peripheral tissues. (p. 943)
List some factors that influence plasma cholesterol levels. Also list the sources and fates of cholesterol in the body.
Factors influencing plasma cholesterol levels include diet (through intake of cholesterol and/or saturated fatty acids), smoking, drinking, and stress. Sources of cholesterol in the body include the intake of animal foods and production from acetyl coenzyme A in the liver (and intestinal cells). Cholesterol is lost from the body when it is catabolized and secreted in bile salts that are eventually excreted in feces. It is used by body cells in plasma membranes and in synthesizing vitamin D and steroid hormones. (p. 944)