BIO Cell Membrane

Module 10

What is cholesterol in relation to cell membranes?

Lipids that insert between phospholipid tails & affect membrane permeability.

What is a transport protein?

Assist in the movement of substances across cell membranes.

What is an aquaporin?

A type of channel protein that allows water to pass through the membrane at a very high rate.

What does permeability mean in the context of cell membranes?

The fluidity of the membrane, which blocks or allows movement of phospholipids.

How do phospholipids form a bilayer in water?

They are not covalently bonded to each other; their hydrophilic heads face outward, while hydrophobic tails face inward, forming a bilayer.

What is the fluid-mosaic model of membrane structure?

It describes the structure of the membrane as a flexible layer of phospholipids with various proteins embedded in it, allowing movement and fluidity.

What are the functions of oligosaccharides attached to glycoproteins and glycolipids on the cell membrane?

They are short chains of 2-60 monosaccharides found on the interior surface of cells. attached to proteins that form glycoproteins, or to lipids forming glycolipids, glycolipids help the immune system identify whether a cell belongs or not

What are channel proteins and carrier proteins?

Amphipathic transmembrane proteins that interact with the hydrophobic region of the phospholipid bilayer, facilitating the transport of substances.

What does it mean that cell membranes are selectively permeable?

Some substances can cross it while others cannot; small lipid-soluble hydrophobic substances like oxygen and carbon dioxide can cross freely.