8.3 - 8.4 Membrane Transport and Homeostasis

What is the mechanism driving diffusion?

• the constant, random movement of particles in a solution

• the stationary nature of particles in a solution

• tendency for particles to move from areas where they are less highly concentrated to areas where they are more highly concentrated

• tendency for particles to move from areas where they are more highly concentrated to areas where they are less highly concentrated

• membrane proteins pumping molecules against their concentration gradient

How is facilitated diffusion different from diffusion?

• it take significantly longer time to happen

• it allows uncharged particles to diffuse across the membrane

• it requires the presence of protein channels in the cell membrane

• it allows smaller particles to diffuse across the membrane

• it requires energy to happen

Facilitated diffusion...

• does not require cellular energy

• requires cellular energy

• is a type of active transport

• allows small and uncharged molecules to diffuse across the membrane

• allows large and charged molecules to diffuse across the membrane

What is the difference between active and passive transport?

• active transport requires cellular energy, whereas passive transport does not

• passive transport requires cellular energy, whereas active transport does not

• active transport moves substances against their concentration gradient

• active transport moves substances down their concentration gradient

• active transport moves larger, charged molecules across the membrane

A substance moving against its concentration gradient is moving from

• an area of high concentration to an area of low concentration

• an area of low concentration to an area of high concentration

A solute moves across a membrane from an area of low concentration of the solute to an area of high concentration. This is an example of...

• passive transport

• active transport

• molecular transport

• facilitated diffusion

• osmosis

Osmosis...

• is when water moves towards the solution with lower concentration of solute

• requires cellular energy

• only occurs when the membrane is impermeable to the solute in solution

• is a type of facilitated diffusion

• is diffusion of water from high to low concentration

In osmosis, water flows towards an area of _______ concentration of water.

In osmosis, water moves towards an area of ______ concentration of solute.

An isotonic solution has....

• an equal concentration of solute as another solution

• a higher concentrations of solute as another solution

• a lower concentration of solute as another solution