Cell Membrane and Transport - Review Notes

Flashcards covering plasma membrane structure, selective permeability, membrane components, and transport types (diffusion, osmosis, and active transport).

What surrounds the cell and acts as a selectively permeable barrier?

The plasma membrane.

What does it mean for the plasma membrane to be selectively permeable?

It allows certain substances to cross while others cannot.

What are the main components of the plasma membrane's phospholipid bilayer?

Phospholipids, cholesterol, and proteins.

How many layers does the bilayer have?

Two layers (a bilayer).

Does passive transport require energy?

No, passive transport does not expend energy.

Diffusion involves the movement of what across the membrane?

Solutes moving from high to low concentration (down their concentration gradient).

Osmosis is the diffusion of what?

Water across a selectively permeable membrane.

Does active transport require energy?

Yes, the cell must expend energy (often via ATP).