Digestion and Absorption Online Quiz

Pancreatic amylase digests starch into the disaccharide maltose (and dextrins) in the small intestine. Maltose is subsequently broken down into glucose by maltase, which is an enzyme bound to the microvilli of the small intestine (not a pancreatic enzyme).

Glucose is absorbed into the epithelial cells of the small intestine via secondary active transport (co-transport) with sodium ions (Na+). Water is absorbed passively by osmosis, and lipids/fatty acids generally cross the membrane via simple diffusion.

Villi and microvilli are structural adaptations of the small intestine that vastly increase the surface area available for the absorption of digested nutrients. Assimilation is the subsequent integration of these nutrients into body tissues, which occurs after absorption.

Pancreatic lipase is produced in the pancreas but is secreted into and functions within the lumen of the small intestine, where it hydrolyzes lipids (triglycerides) into fatty acids and glycerol.

Pepsin is an endopeptidase secreted in the stomach that hydrolyzes proteins into smaller polypeptides and eventually amino acids. While pepsin primarily cleaves proteins into shorter peptide chains rather than individual amino acids, option D is the only option that correctly identifies proteins as the substrate.

The pancreas is an accessory organ of the digestive system that produces and secretes digestive enzymes, such as pancreatic amylase, into the duodenum of the small intestine to chemically break down carbohydrates. Food does not pass through the pancreas itself, and peristalsis is carried out by the muscular walls of the digestive tract. Pepsin is secreted by the stomach, not the pancreas.