Selective Permeability of Membranes

Part A

Structure A in this animation is a(n) _____.

To view the animation, click here. Then click on structure A in the image to start the animation.

	transport protein
	receptor molecule
	antibody
	structural protein
	enzyme

Correct

The protein is allowing solute molecules to enter the cell.

Part B

Which of these cannot rapidly pass directly through the phospholipids of the plasma membrane?

	B, C, and D
	C only
	B only
	D only
	A only

Correct

Ions, such as hydrogen ions, and hydrophilic molecules, such as water and glucose, cannot rapidly pass directly through the phospholipids of a plasma membrane. To move rapidly through the membrane, they must pass through membrane transport proteins.