In Type 2 diabetes, insulin levels are frequently normal, yet the target cells are less sensitive to the effects of insulin. This suggests that the target cells:
(a) Are impermeable to insulin
(b) May lack enough insulin receptors
(c) Cannot convert insulin to an active form
(d) Have adequate internal supplies of glucose
(e) Both b and c

검증된 단계별 안내

Step 1: Understand the role of insulin in the body. Insulin is a hormone that facilitates the uptake of glucose by target cells, primarily muscle and fat cells, by binding to insulin receptors on their surface.

Step 2: Recognize that in Type 2 diabetes, insulin levels can be normal or even elevated, but the cells do not respond properly to insulin. This condition is known as insulin resistance.

Step 3: Analyze the options given: (a) impermeability to insulin is unlikely because insulin acts by binding to receptors, not by entering the cell; (b) lacking enough insulin receptors would reduce the cell's ability to respond to insulin; (c) inability to convert insulin to an active form is not typical because insulin acts extracellularly by receptor binding; (d) having adequate internal glucose supplies does not explain reduced sensitivity to insulin.

Step 4: Since insulin resistance often involves a reduced number or function of insulin receptors, option (b) is plausible. Option (c) is less likely because insulin does not need to be converted inside the cell to be active.

Step 5: Conclude that the best explanation is that target cells may lack enough insulin receptors, making option (b) the most accurate choice.

비슷한 문제에 대한 검증된 영상 답변:

이 영상 해법은 위 문제에 도움이 된다고 튜터들이 추천한 것입니다.

주요 개념

질문에 올바르게 답하기 위해 반드시 이해해야 하는 핵심 개념들은 다음과 같습니다.

Insulin Resistance

Insulin resistance occurs when target cells, such as muscle or fat cells, respond poorly to insulin despite normal or high insulin levels. This reduces glucose uptake, leading to elevated blood sugar. It is a hallmark of Type 2 diabetes and involves impaired insulin signaling pathways.

Insulin Receptors and Their Role

Insulin receptors are proteins on the surface of target cells that bind insulin and trigger glucose uptake. A reduced number or malfunction of these receptors can decrease cell sensitivity to insulin, contributing to insulin resistance seen in Type 2 diabetes.

Mechanism of Insulin Action

Insulin acts by binding to its receptor, initiating a cascade that allows glucose transporters to move to the cell membrane and facilitate glucose entry. Insulin itself is active and does not require conversion inside the cell, so inability to convert insulin is not a typical cause of insulin resistance.