BIOMOLECULES AND ENZYMES

Detailed explanation-1: -The pre-absorptive cephalic phase of insulin secretion is elicited during the first ten min of a meal and before glucose levels rise.

Detailed explanation-2: -Insulin is secreted primarily in response to glucose, while other nutrients such as free fatty acids and amino acids can augment glucose-induced insulin secretion. In addition, various hormones, such as melatonin, estrogen, leptin, growth hormone, and glucagon like peptide-1 also regulate insulin secretion.

Detailed explanation-3: -When people eat a food containing carbohydrates, the digestive system breaks down the digestible ones into sugar, which enters the blood. As blood sugar levels rise, the pancreas produces insulin, a hormone that prompts cells to absorb blood sugar for energy or storage.

Detailed explanation-4: -The insulin level rises already in the 1st min after the start of food ingestion, whereas the glucose level begins to increase only in the 3rd min if carbohydrate-rich food is eaten.

Detailed explanation-5: -Incretin is a group of hormones secreted by the enteroendocrine cells after ingestion of food, and it stimulates -cells to increase insulin secretion, which, in turn, prevents an increase in the postprandial blood glucose level.