**Question:** After overnight fasting, levels of Glucose transporters are reduced in

A. Liver
B. Muscle
C. Fat
D. Kidney

**Correct Answer:** **A. Liver**

**Core Concept:** Glucose transporters are proteins that facilitate the transport of glucose across cell membranes. They play a crucial role in maintaining glucose homeostasis in the body. In response to fasting, the liver plays a significant role in regulating glucose levels by synthesizing glycogen and producing glucose through gluconeogenesis, which requires glucose transporters to facilitate the uptake of glucose into the liver cells.

**Why the Correct Answer is Right:** In response to fasting, the liver undergoes a process called gluconeogenesis, which produces glucose from non-carbohydrate sources like glycerol and amino acids. This process requires glucose transporters to facilitate the uptake of glucose into the liver cells. As a result, the levels of glucose transporters are reduced in the liver.

**Why Each Wrong Option is Incorrect:**

**A. Muscle:** While muscle cells also require glucose transporters for glucose uptake, the reduction in glucose transporters is not specifically related to fasting. Muscle cells primarily use glucose during physical activity, and fasting does not directly impact glucose transporter levels in muscle cells.

**B. Fat:** Fat cells do not require glucose transporters for glucose uptake, as they primarily store fat and do not actively use glucose as a primary source of energy. Therefore, fasting-induced changes in glucose transporter levels are not relevant to fat cells.

**C. Kidney:** Glucose transporters are involved in glucose reabsorption in the kidney, allowing them to maintain blood glucose levels. However, the reduction in glucose transporters is not directly associated with fasting. Instead, fasting leads to a decrease in insulin secretion, which enables the kidney to reabsorb more glucose from the filtrate and excrete excess glucose.

**D. Kidney:** Similar to option C, glucose transporters are involved in glucose reabsorption in the kidney to maintain glucose homeostasis. However, the reduction in glucose transporters during fasting is not directly associated with the kidney. Instead, fasting affects insulin secretion, which influences glucose reabsorption in the kidney.

**Why the Correct Answer is Right:** The reduction in glucose transporters in the liver is directly linked to fasting, as it is the primary organ involved in gluconeogenesis, the process of generating glucose from non-carbohydrate sources. By reducing glucose transporter levels, the liver becomes more efficient in producing glucose during fasting, helping to maintain blood glucose levels and prevent hypoglycemia.