LIFE SCIENCE

OBJECTIVE LIFE SCIENCE

CELL BIOLOGY

Question [CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
What forms the channels and pumps in the phospholipid bilayer?
A
carbohydrates
B
proteins
C
hydrophilic heads
D
lipids
Explanation: 

Detailed explanation-1: -Integral proteins may serve as channels or pumps to move materials into or out of the cell. Peripheral proteins are found on the exterior or interior surfaces of membranes, attached either to integral proteins or to phospholipid molecules.

Detailed explanation-2: -Channel proteins are transmembrane proteins that move molecules from high to low concentration without binding to them or using energy. Because they do not use energy, channel proteins are a form of passive transport.

Detailed explanation-3: -Transmembrane channels, also called membrane channels, are pores within a lipid bilayer. The channels can be formed by protein complexes that run across the membrane or by peptides. They may cross the cell membrane, connecting the cytosol, or cytoplasm, to the extracellular matrix.

Detailed explanation-4: -Aquaporins, belonging to the family of major intrinsic proteins, also form pores in the membrane facilitating mainly the transport of water into and out of the cell. Aquaporins form tetramers in the cell membrane, with each of the four monomers acting as a water channel.

There is 1 question to complete.