Active Transport

What is the difference between active and passive transport?

• Active transport requires energy; passive transport does not.

• Active transport moves molecules across cell membranes; passive transport does not.

• Active transport involves oxygen and water molecules; passive transport does not.

• Active transport occurs only in nerve cells; passive transport occurs in all the body's cells.

The cell membrane is semi-permeable. What does "permeable" mean?

• Extremely thick

• Extremely thin

• Able to be penetrated

• Able to be broken

The natural spreading of particles through a liquid or gas is called:

• Dilution

• Diffusion

• Differentiation

• Fusion

What does it mean when substances move "down a concentration gradient?" Choose the best answer.

• They move from areas where there are few particles to areas where there are lots of particles

• They move from areas with lots of water to areas where there is little water

• They move from one side of a cell membrane to the other

• They move from areas where there are a lot of particles to areas where there are few particles

If you were looking for transport proteins, where would you find them?

• Inside a cell's nucleus.

• Lodged within a cell's membrane.

• Inside a cell's cytoplasm.

• Inside a cell's endoplasmic reticulum.

How do transport proteins move substances across membranes?

• They move inside the membrane, carrying the substance

• They change shape

• They rip open a temporary hole in the membrane

• They increase the concentration gradient inside the cell

What might happen if a cell did not have any ATP?

• It would not have enough energy to carry out active transp

• Its transport proteins would be made of carbohydrates instead

• Its cell membrane would no longer be semi-permeable

• Its concentration gradient would be steeper

What can you infer about the membrane of a vesicle or vacuole?

• It is made out of transport proteins

• It is made out of water molecules

• It's made out of the same substance as the cell membrane

• It's made out of cellulose

What is the main function of white blood cells?

• To fight germs

• To absorb substances into cells

• To supply cells with energy

• To even out concentration gradients

What process releases substances from a cell?

• Hypocytosis

• Endocytosis

• Mesocytosis

• Exocytosis