What is diffusion?

• Particles of a substance being moved against their concentration gradient by exocytosis.

• Particles of a substance being moved across a cell membrane by protein pumps.

• Particles of a substance moving from an area of low concentration to an area of high concentration.

• Particles of a substance moving from an area of high concentration to an area of low concentration.

What is the movement of molecules across the cell membrane without using cellular energy?

• active transport

• phagocytosis

• endocytosis

• passive transport

Which of these are types of passive transport? Check all that apply.

• diffusion

• phagocytosis

• facilitated diffusion (including osmosis)

• protein pumps

What makes up most of the cell membrane?

• a phospholipid bilayer

• a carboniferous bilayer

• a nitrogenous bilayer

• a phosphorescent bilayer

What type of molecule is shown?

• a carbohydrate

• a nucleic acid

• a phospholipid

• a protein

What is A pointing to?

What is B pointing to?

• A: phospholipid bilayer,

  B: fatty acids

• A: hydrophilic heads,

  B: hydrophobic tails

• A: hydrophobic tails,

  B: hydrophilic heads

• A: fatty acids,

  B: phospholipid bilayer

What is it called when molecules diffuse through protein channels, because they cannot diffuse directly through the membrane?

• facilitated diffusion

• active transport

• facilitated action

• active transfusion

What structure involved in facilitated diffusion is indicated by the number 1?

• a protein pump

• endocytosis

• exocytosis

• a protein channel

What type of structures let water molecules pass through the membrane?

• embedded carbohydrates

• aquaporins

• protein pumps

• aqua facilitation

The diffusion of water molecules through a semipermeable membrane is...

• vacuole

• mitochondria

• active transport

• osmosis