Question

Homeostasis is required by all organisms to maintain a stable internal environment for normal physiological function. Diabetes is caused by a lack of insulin, which is a protein hormone that is essential in the regulation of blood glucose. The following diagram depicts the mechanism of insulin action:

Which of the following statements best explains how insulin is involved in maintaining homeostasis?

A) Insulin binds to its membrane receptor, triggering a response in the target cell. Inside the cell, the response includes the conversion of glucose to glycogen, demonstrating positive feedback.

B) The glucose transporter protein initiates insulin transport into the cell, and signal transduction results in glucose conversion to glycogen, fatty acid, and pyruvate.

C) Through negative feedback, insulin and glucose work together to produce glycogen, fatty acids, and pyruvate.

D) When insulin binds to cell receptors, blood sugar drops because glucose enters the target cell and is converted to glycogen. This is an example of negative feedback.

Answer 1

Hint: Homeostasis is the ability of an organism to maintain a stable internal environment. In the context of blood sugar regulation, homeostasis involves maintaining a balance between glucose uptake by cells and glucose release by the liver.

Complete Step-by-step Answer: Option A is incorrect because positive feedback is a process in which the output of a system reinforces itself, leading to an increase or decrease in the output. In this case, the conversion of glucose into glycogen does not directly lead to an increase in insulin production.

Option B is incorrect because the glucose transporter protein is responsible for transporting glucose into cells, not insulin. Signal transduction is the process by which cells receive and respond to signals, but it is not directly involved in the conversion of glucose into glycogen, fatty acids, and pyruvate.

Option C is incorrect because insulin and glucose do not work simultaneously to produce glycogen, fatty acids, and pyruvate. Insulin promotes glucose uptake by cells and the conversion of glucose to glycogen. Glucose can also be converted into fatty acids and pyruvate, but insulin does not directly regulate these processes.

Option D is correct because insulin binds to cell receptors, which triggers a series of events that lead to the uptake of glucose by cells. When glucose is taken up by cells, it is converted into glycogen, which is stored for later use. This reduces the amount of glucose in the blood, which helps to maintain homeostasis.

Hence the Correct Answer is Option D

Note: The mechanism of insulin action is a complex process that involves a number of different molecules and signaling pathways. The explanation provided in this answer is a simplified overview of the process.