Question

question 18
which of the following statements about blood glucose is false?
a after a carbohydrate - rich meal, the pancreas secretes insulin, which causes cells to take glucose out of the blood and use it for
cellular energy or anabolic reactions, such as glycogenesis and lipogenesis.
b
c when blood glucose drops, the pancreas secretes glucagon, which causes cells to stop using glucose, and signals the liver to
break down glycogen (thereby releasing stored glucose into the blood).
d none of the above statements is false.
2 points

Explanation:

• Option A: After a carbohydrate - rich meal, insulin is secreted by the pancreas. Insulin causes cells (such as muscle, liver, and adipose cells) to take up glucose. Glycogenesis (formation of glycogen from glucose) and lipogenesis (formation of lipids from glucose) are anabolic reactions (building - up reactions) that occur when there is an excess of glucose. So, this statement is correct.
• Option B: Glucagon, when secreted by the pancreas (in response to low blood glucose levels), does not cause cells to stop using glucose. Instead, it signals the liver to break down glycogen (glycogenolysis) and also promotes gluconeogenesis (synthesis of glucose from non - carbohydrate sources). Cells, especially the brain, continue to use glucose. So, this statement is false.
• Option C: Glucagon signals the liver to break down glycogen (glycogenolysis), which releases stored glucose into the blood. This is a correct physiological response to low blood glucose levels. So, this statement is correct.

Answer:

B. When blood glucose drops, the pancreas secretes glucagon, which causes cells to stop using glucose, and signals the liver to break down glycogen (thereby releasing stored glucose into the blood).