Cell Membrane Flashcards

Flashcards based on lecture notes about the cell membrane.

What is the cell membrane?

A biological membrane that separates the interior of cells from the outside environment.

What is the cell membrane made of?

It consists of a lipid bilayer, including cholesterols, and membrane proteins (integral and peripheral).

What are the main functions of the cell membrane?

Protection, cell adhesion, ion conductivity, cell signaling, and attachment surface for extracellular structures.

What are the main components of the cell membrane?

Phospholipids, proteins, and carbohydrates.

What are the main lipid components of the cell membrane?

Phospholipids, cholesterol, and glycolipids.

What is the function of glycolipids in the cell membrane?

Cell recognition.

What role do proteins play in cell membranes?

Carriers or channels for cell transport.

What are the functions of integral proteins in the plasma membrane?

Anchoring cells to other cells or surfaces, channeling or transporting molecules, and acting as cell receptors.

What was proposed in the Sandwich model (Danielli and Davson Model)?

Two layers of lipid (phospholipid) molecules with polar heads facing outwards.

What is the fluid mosaic model of the cell membrane?

A two-dimensional liquid where lipids and proteins can move more or less freely.

What is membrane asymmetry?

An unequal distribution of molecules between monolayers.

What structure contributes to the asymmetry of the cell membrane?

Glycocalyx.

What helps the plasma membrane remain fluid?

The mosaic nature of the membrane.

What factors increase membrane fluidity?

Shorter fatty acid tails and unsaturated fatty acids.

How does cholesterol affect membrane fluidity?

It stabilizes the membrane and prevents clustering of phospholipids.

What is cholesterol's role as regulator of membrane fluidity?

Decreases fluidity at high temperatures and increases fluidity at low temperatures.