Cell Membrane and Membrane Transport

Flashcards for review of key concepts related to cell membranes and membrane transport mechanisms.

What is the primary function of the cell membrane?

To act as a selectively permeable barrier that regulates what enters and exits the cell.

What are the main components of the cell membrane that influence its structure and function?

Phospholipids, cholesterol, oligosaccharides, integral and peripheral membrane proteins.

How does temperature affect membrane fluidity?

Changes in temperature can alter the membrane's fluidity by affecting the lipid structure.

What are the differences between passive and active transport?

Passive transport does not require energy and involves the movement of substances down their concentration gradient, while active transport requires energy to move substances against their gradient.

Define osmosis in the context of cell membranes.

Osmosis is the diffusion of water across a selectively permeable membrane.

What is the role of aquaporins in the cell membrane?

Aquaporins facilitate the rapid transport of water across the cell membrane.

What is the difference between phagocytosis and pinocytosis in endocytosis?

Phagocytosis refers to 'cellular eating' where large particles are engulfed, while pinocytosis refers to 'cellular drinking' where fluids and small molecules are taken up.

What is the Na+-K+ pump and its function?

The Na+-K+ pump moves 3 sodium ions out of the cell and 2 potassium ions into the cell, consuming ATP and creating an electrochemical gradient.

How does oral rehydration therapy utilize cotransport?

ORT uses the sodium-glucose cotransport mechanism to enhance the absorption of sodium and glucose in intestinal cells during dehydration.

What is the fluid mosaic model?

The fluid mosaic model describes the cell membrane as a mosaic of various proteins embedded in a fluid phospholipid bilayer.