Active and Passive Transport Quiz

What type of molecules are able to diffuse through the cell membrane?

Small, non-polar molecules

What types of molecules cannot diffuse through the cell membrane?

Anything large or anything with a charge (ions and polar molecules)

What is the energy source in active transport?

ATP

Name some characteristics of passive transport

1) moves from high to low concentration

2) moves down the concentration gradient

3) requires no energy

4) trying to obtain equilibrium

5) integral proteins called carrier proteins or channels

Name some characteristics of active transport

1) requires energy to occur

2) moves from low to high concentration

3) moves up concentration gradient

4) trying to move away from equilibrium

5) integral proteins called pumps

Which type of transport occurs naturally?

Passive

What are the two parts of a solution?

Solute and solvent

What is concentration?

Amount of solute relative to amount of solvent

Name two ways to INCREASE solution concentration

1) increase/add solute

2) decrease/remove solvent

What is the result of solute-solute collisions?

Molecules try to spread as far apart as possible

diffusion

The movement of solute from an area of high concentration to low concentration caused by random motion of gases and liquids

four types of passive transport

1) diffusion

2) osmosis

3) facilitated diffusion

4) ion channels

three types of active transport

1) endocytosis

2) exocytosis

3) pumps

osmosis

Diffusion of water across the cell membrane

A solution with high concentration is low in

Solvent concentration (in most cases, water)

What are the three types of solutions?

1) hypotonic

2) hypertonic

3) isotonic

What happens to the cell in a hypotonic solution?

Cell expands due to water moving in

What happens to the cell in a hypertonic solution?

It shrinks due to decrease of water

True or false: isotonic concentrations are not equal inside and outside the cell

False, concentrations are always equal inside and outside the cell in an isotonic solution

What is turgor pressure?

Pressure exerted on the cell wall

Define a hypotonic solution

The concentration of solutes inside the cell are higher than the concentration of solutes outside the cell

Define a hypertonic solution

The concentration of solutes inside the cell are lower than the concentration of solutes outside the cell

Can small, non-polar molecules diffuse through the membrane on their own?

Yes

Can small, polar molecules diffuse through the membrane on their own? (They are small!!)

No, because they have a charge

Can small, charged ions diffuse through the membrane on their own? (They are small!)

No, Since they still have a charge

Can large (monomer sized), non-polar molecules diffuse through the membrane on their own?

No, they are too large to diffuse through

Can large, polar molecules diffuse through the cell membrane?

No, they are too large and polar to pass through without assistance.

How do ions and big molecules make it across the membrane?

Through proteins by transport

Define facilitated diffusion

Movement of molecules across cell membrane from areas of high concentration to low concentration using a carrier protein (does not require any energy)

Define ion channels

Movement of molecules across cell membrane by creating a passageway for ions to travel through (Does not require any energy)

Do exocytosis and endocytosis require energy?

Yes, they use ATP

Define endocytosis

(Active transport) Bringing molecules into the cell against their concentration gradient

Define exocytosis

(Active transport) releasing large molecules out of the cell membrane against concentration gradient, reverse of endocytosis

What are the steps to endocytosis?

1) pocket forms around external material

2) plasma (cell) membrane folds around materials

3) membrane fuses forming a vesicle inside the cell

What are the steps to exocytosis?

1) vesicle formed around molecules inside cell

2) vesicle fuses with membrane

3) vesicle releases contents to outside

Does a pump require energy?

Yes, a pump always requires a form of energy to work

True or false: substances that cannot diffuse directly between the phospholipids cannot get into the cell

False

What surrounds the vesicle as it is being made during endocytosis?

Cell membrane

True or False: a vesicle is formed during exocytosis

False

In which type of cell is the sodium-potassium pump found?

Nerve and muscle cells

Why are sodium and potassium important for our bodies?

Create electrolytes - send signals from brain to our muscles

Which proteins allow a change in electrical potential (signal) to be sent down the length of a nerve cell?

Sodium-potassium pumps

Under what circumstances would the cell use exocytosis?

If the cell needed to get rid of any unwanted substance such as extracellular fluid stored in a vesicle

Does facilitated diffusion use a carrier protein?

Yes

Define concentration gradient

Two areas with a different solute concentration

True or false: A carrier protein changes shape during facilitated diffusion

True, it changes shape so that it can safely move the molecule through the cell membrane

True or false: Facilitated diffusion can occurred in either direction

True