Biology CB11 Quiz Diffusion

What is diffusion?

• the movement of molecules from an area of high concentration of the molecules to an area with a lower concentration.

• the movement of molecules from an area of low concentration of the molecules to an area with a higher concentration.

• the state of having an equal number of molecules on both sides of a membrane.

• the movement of ions across a membrane by using transport proteins.

The difference in the concentrations of the molecules in the two areas is called the__________________.

• concentration quotient

• concentration gradient

• concentration ratio

• concentration equilibrium

Equal concentration of molecules on both sides of a membrane is also known as ___________________.

• equilibrium

• gradient

• diffusion

• ion channel

Facilitated diffusion is the diffusion of solutes through transport ____________ in the cell membrane.

• lipids

• cells

• proteins

• acids

Which of these are transport proteins?(Check all that apply)

• channel proteins

• ionic inhibiter proteins

• gated channel proteins

• facilitated proteins

• carrier proteins

This type of transport protein acts like a pore in the membrane that lets water molecules or small ions through quickly.

• active protein

• carrier protein

• gated channel protein

• channel protein

This transport protein can open or close allowing a molecule to pass through the membrane. They have a binding site that is specific for a given molecule or ion.

• active protein

• carrier protein

• gated channel protein

• channel protein

This is a transport protein that is specific for an ion, molecule, or group of substances. Carrier proteins move ions or molecules across the membrane by changing shape after the binding of the ion or molecule.

• active protein

• carrier protein

• gated channel protein

• channel protein

Why don't ions move easily across the cell membrane?

• ions are too large

• ions are too small

• ions are are charged (polar)

• ions are not charged (non-polar)

Facilitated diffusion is a type of passive transport.

• true

• false