Question

which components of the plasma membrane receive chemical signals from outside the cell?
a) cholesterol within phospholipid bilayer
b) membrane protein on inner cell surface
c) transport protein for glucose
d) carbohydrate chain attached to membrane protein

Explanation:

Carbohydrate - chains attached to membrane proteins (glycoproteins) act as receptors for chemical signals from outside the cell. Cholesterol in the phospholipid bilayer mainly contributes to membrane fluidity and stability. Membrane proteins on the inner cell - surface are not the primary receptors for external signals. Transport proteins for glucose are mainly for transporting glucose, not for receiving chemical signals.

Answer:

D) carbohydrate chain attached to membrane protein