MUSCLE PHYSIOLOGY

Detailed explanation-1: -GLUT4 is an insulin-responsive glucose transporter that is found in the heart, skeletal muscle, adipose tissue, and brain. It is present in the cytoplasm of cells in vesicles from which it is translocated to the plasma membrane under the influence of insulin.

Detailed explanation-2: -In the intestine and renal proximal tubule, glucose is transported against a concentration gradient by a secondary active transport mechanism in which glucose is cotransported with sodium ions.

Detailed explanation-3: -The entry of glucose into these cells is a function of insulin. There are certain receptors present on the surface of these cells to which the insulin binds, this causes the molecules of GLUT4 to arrive at the surface of the cell. GLUT is a glucose transport component that allows the cells to take in the glucose.

Detailed explanation-4: -GLUT4 functions for the insulin-dependent translocation of glucose. Thus, insulin stimulates the uptake of glucose by GLUT4 in the muscle cell where hexokinase converts it to glucose-6-phosphate so that the cell may utilize it for either glycolysis for energy or for the formation of glycogen when glucose is abundant.