LIFE SCIENCE

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: -When glucose in the blood binds to glucose receptors on the beta cell membrane, a signal cascade is initiated inside the cell that results in insulin stored in vesicles in these cells being released into the blood stream. Increased insulin levels cause the uptake of glucose into the cells.

Detailed explanation-3: -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-4: -Glucose transporter (GLUT) is a facilitative transport protein involved in glucose translocation across the cell membrane. Seven isoforms of GLUT have been identified and their names are based on order of cloning as GLUT1 to GLUT7 [58].

Detailed explanation-5: -Glucose enters cells by facilitated diffusion = carrier mediated transport using a GLUT protein.