Cell membrane proteins | Cells | MCAT | Khan Academy

What is the composition of proteins in most cell membranes?

Most cell membranes have about 50% or less protein.

What are the two main types of proteins found in the cell membrane?

Integral proteins and peripheral proteins.

How are integral proteins characterized?

Integral proteins are integrated throughout the entire membrane and are difficult to remove.

What do we call proteins that are usually located on the periphery of the cell membrane?

Peripheral proteins.

What is a lipid-bound protein?

A rare type of protein that is stuck on the interior of the cell membrane.

What is the function of channel proteins?

Channel proteins allow substances to pass through the cell membrane, often following the concentration gradient.

How do carrier proteins function differently from channel proteins?

Carrier proteins can carry substances into and out of the cell and can go against the concentration gradient, sometimes using energy (ATP).

What are glycoproteins?

Glycoproteins are proteins with sugar chains attached, involved in cell recognition and signaling.

What role do channel proteins play in maintaining homeostasis?

Channel proteins help regulate the intake and removal of ions, allowing the cell to maintain balance.

Why are lipid-bound proteins considered rare?

They are difficult to find because they interact less with the exterior or interior environments, limiting their functional significance.