Question 23M.1.SL.TZ1.3

Cytochrome reductase is a transmembrane protein which acts as a H⁺ channel in respiration. Which characteristic allows cytochrome reductase to be a transmembrane protein?

A.  It is hydrophilic except for the central core which is a hydrophobic channel.

B.  It has hydrophobic regions embedded in the membrane and hydrophilic regions exposed on both sides of the membrane.

C.  It has a hydrophobic central core acting as a channel and a hydrophilic region embedded in the membrane.

D.  It is hydrophobic except for the part in contact with the phospholipid membrane.