Name: ______________________________________________ Date: _________________________ Period: ______

Cell Unit Review Worksheet | Part II | KEY Directions: Answer the following questions the BEST you can without any help. After you have finished, notice what

you don’t know and make note of this by highlighting the question. Now use notes, etc to finish.

Passive Transport 1. Define concentration gradient: Difference in concentration of a substance from 1 location to another.

(Explaination: Molecules diffuse down their concentration gradient – from a region of higher concentration to

a region of lower concentration)

2. What is passive transport (be sure to mention the concentration gradient)?

The movement of molecules from an area of high concentration to low concentration. The molecules are

moving down the concentration gradient = No energy is required.

3. Fill in the table:

Types of Passive Transport Explanation

Diffusion

Movement of molecules from an area of high concentration to low

concentration. Movement continues until equilibrium is reached. No energy

is required.

Osmosis Diffusion of water from an area of high to low concentration. Movement

continues until equilibrium is reached. No energy is required.

Facilitative Diffusion

Larger molecules enter/exit with the help of protein channels in the plasma

membrane. Movement continues until equilibrium is reached. No energy is

required.

4. What might cause a molecule to move from the outside of the cell to the inside (with no energy)?

Molecules would move from outside of the cell to the inside, if there was a higher concentration of molecules

outside of the cell than inside the cell. This would cause the molecules to move down the concentration gradient

(no energy required).

5. Label the type of solution each red blood cell is in. Draw dots to show where the solutes are (inside/outside of

cell) and arrows on the cell to show the direction of osmosis.

(Can you explain what is happening in each picture?)

Active Transport

6. Define active transport (be sure to mention the concentration gradient): When molecules move from a LOW to a HIGH concentration, they are said to move against their concentration gradient. For this to happen ATP (energy) is required.

7. Compare/Contrast:

8. Label the following type of active transport and then explain what is happening in each picture:

Type of Active Transport: Endocytosis

9. Label the following type of active transport and then explain what is happening in each picture:

Type of Active Transport: Exocytosis

Phagocytosis Pinocytosis Same

Cell membrane folds

inward and fuses together;

surrounding the substance

in a pocket

The pocket pinches off

INSIDE the cell, forming a

vesicle

The vesicle fuses with a

lysosome/similar vesicle.

The enzymes break down

the vesicle membrane and

its contents, which are

released into the cell.

The cell forms a vesicle

around material that needs

to be removed/leave.

The cell membrane releases

the material OUT of the cell.

The vesicle is transported

to the cell membrane. The

vesicle fuses with the cell

membrane.

A type of

endocytosis (active

transport – ATP

required)

Uses vesicles

Process of taking in

materials

When a cell takes in

a liquid particle

When a cell takes in

a solid particle