Describe the process of lipid digestion and absorption in the small intestine.
What will be an ideal response?
Dietary fat in the form of large fat globules composed of triglycerides is emulsified by the detergent action of bile salts into a suspension of smaller fat droplets. This lipid emulsion prevents the fat droplets from coalescing and thereby increases the surface area available for attack by pancreatic lipase. Lipase hydrolyzes the triglycerides into monoglycerides and free fatty acids. These water-insoluble products are carried to the luminal surface of the small-intestine epithelial cells within water-soluble micelles, which are formed by bile salts and other bile constituents. When a micelle approaches the absorptive epithelial surface, the monoglycerides and fatty acids leave the micelle and passively diffuse through the lipid bilayer of the luminal membranes.The monoglycerides and free fatty acids are resynthesized into triglycerides inside the epithelial cells. These triglycerides aggregate and are coated with a layer of lipoprotein from the endoplasmic reticulum to form water-soluble chylomicrons. Chylomicrons are extruded through the basal membrane of the cells by exocytosis. Chylomicrons are unable to cross the basement membrane of capillaries, so instead they enter the lymphatic vessels, the central lacteals.
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Which of the following lunches best fits into a meal plan suggesting that a person eat 1 cup vegetables, 2 ounces grains, and 2 ounces protein foods at lunch?
a. sandwich of 2 slices whole-wheat bread, 4 tablespoons nut butter, and 1 tablespoon honey with salad of 1 cup raw spinach b. sandwich of 2 slices whole-wheat bread and 2 ounces ham, 1 boiled egg, and 1 cup vegetable juice c. stir-fry of 1/2 cup tofu and 1 cup mixed vegetables on 1 cup cooked rice d. 2 ounces broiled salmon and 1 cup thick tomato sauce over 1/2 cup cooked pasta e. ½ avocado, ½ cup yogurt, 2 tablespoons peanut butter, and 1 cup cooked spinach
Fruit provides a good source of potassium
Indicate whether the statement is true or false
Which statement about basal metabolism is true? a. It supports the voluntary but not the unconscious work that the body performs
b. It can be changed rapidly through vigorous exercise. c. It accounts for the smallest component of the average person's daily energy expenditure. d. It is directly controlled by the hormone thyroxine. e. It increases in response to malnutrition or fasting.
According to the US Census Bureau, the world’s population will be an estimated ________ billion by 2050.
a. 5 b. 6.5 c. 7.5 d. 8 e. 9