Which of the following is absorbed into the blood capillary of the villus by facilitated diffusion?
Which of the following is absorbed into the blood capillary of the villus by facilitated diffusion?
The correct option is: B
Explanation of the correct option:
Fatty acids are not directly absorbed into the bloodstream. They are converted into micelles with the help of bile salts. At a later stage, the bile salts are removed and a layer of protein is formed over the fatty acid called chylomicrons. These are then transported into the lacteals present within the villi in the small intestine. These are absorbed into the lacteals by simple diffusion. Simple diffusion is a process by which the substances move from a region of higher concentration to a region of lower concentration.
Explanation of the incorrect option:
Option A: Absorption of fructose takes place by facilitated diffusion. In facilitated diffusion, there is a carrier protein that helps in the absorption of fructose into the bloodstream. It is a passive process and thus does not require energy.
Option C: Glucose and amino acids are absorbed into the bloodstream by active transport. Active transport is a process in which the molecules are transported from a region of lower concentration to a region of higher concentration with the expense of energy.
Option D: Free amino acids are absorbed and transported in the plasma as well as possibly in the blood cells. These two pools may serve unique functions and therefore deserve individual attention. Peptides are absorbed by the enterocytes. Amino acids in the peptide form appear to be absorbed more readily than free amino acids.
Final answer: Fatty acids are absorbed into the blood capillary of the villus by facilitated diffusion.
The correct option is: B
Explanation of the correct option:
Fatty acids are not directly absorbed into the bloodstream. They are converted into micelles with the help of bile salts. At a later stage, the bile salts are removed and a layer of protein is formed over the fatty acid called chylomicrons. These are then transported into the lacteals present within the villi in the small intestine. These are absorbed into the lacteals by simple diffusion. Simple diffusion is a process by which the substances move from a region of higher concentration to a region of lower concentration.
Explanation of the incorrect option:
Option A: Absorption of fructose takes place by facilitated diffusion. In facilitated diffusion, there is a carrier protein that helps in the absorption of fructose into the bloodstream. It is a passive process and thus does not require energy.
Option C: Glucose and amino acids are absorbed into the bloodstream by active transport. Active transport is a process in which the molecules are transported from a region of lower concentration to a region of higher concentration with the expense of energy.
Option D: Free amino acids are absorbed and transported in the plasma as well as possibly in the blood cells. These two pools may serve unique functions and therefore deserve individual attention. Peptides are absorbed by the enterocytes. Amino acids in the peptide form appear to be absorbed more readily than free amino acids.
Final answer: Fatty acids are absorbed into the blood capillary of the villus by facilitated diffusion.
