Question

Where are GLUT carriers located in an unstimulated muscle?

A. in the plasma membrane facing the external environment
B. in the plasma membrane facing the internal environment
C. within cytoplasmic vesicles
D. There are no GLUT carriers present.

Answer 1

In an unstimulated muscle, GLUT4 carriers are located within cytoplasmic vesicles and are translocated to the plasma membrane upon insulin stimulation to aid in glucose uptake.

Step-by-step explanation:

GLUT carriers, specifically GLUT4, are located within cytoplasmic vesicles in an unstimulated muscle cell. Upon the binding of insulin to receptors on the plasma membrane, a cascade of events is triggered that causes these vesicles carrying GLUT4 to fuse with the plasma membrane. This fusion process allows GLUT4 to facilitate the uptake of glucose into the cell through facilitated diffusion. Therefore, the correct answer to where GLUT carriers are located in an unstimulated muscle is within cytoplasmic vesicles (C).