3: Movement into and out of cells

Question 1

Describe diffusion

Answer 1

The net movement of particles from a region of their higher concentration to a region of their lower concentration (i.e. down a concentration gradient) as a result of their random movement

Question 2

Where does the energy for diffusion come from?

Answer 2

It comes from the kinetic energy of random movements of molecules and atoms

Question 3

How do some substances move into and out of cells?

Answer 3

By diffusion through the cell membrane

Question 4

Describe the importance of diffusion of gases and solutes in living organisms

Question 5

Which factors affect the rate of diffusion

Answer 5

Surface area, Temperature, Concentration gradient and Distance

Question 6

How does surface area affect the rate of diffusion?

Answer 6

The greater the surface area, the higher the rate of diffusion

Question 7

How does temperature affect the rate of diffusion?

Answer 7

The higher the temperature, the higher the rate of diffusion

Question 8

How does the concentration gradient affect the rate of diffusion?

Answer 8

The greater the difference in concentration, the higher the rate of diffusion

Question 9

How does distance affect the rate of diffusion?

Answer 9

The shorter the distance, the higher the rate of diffusion

Question 10

What type of membrane that water diffuses through during osmosis?

Answer 10

A partially permeable membrane

Question 11

In what state is a plant cell in when it is in a solution of lower water potential?

Answer 11

Flaccid

Question 12

In what state is a plant cell in when it is in a solution of equal water potential?

Answer 12

in equilibrium

Question 13

In what state is a plant cell in when it is in a solution of higher water potential?

Answer 13

Turgid

Question 14

Why do plants wilt?

Answer 14

When plants aren’t given enough water, the cells inside the leaves and stem become flaccid and droop.

Question 15

In what state is a animal cell in when it is in a solution of lower water potential?

Answer 15

Crenation (or the cell is crenated)

Question 16

In what state is a animal cell in when it is in a solution of equal water potential?

Answer 16

in equilibrium

Question 17

In what state is a animal cell in when it is in a solution of higher water potential?

Answer 17

Haemolysis (the cell is haemolytic)

Since animal cells do not have a cell wall, they will keep expanding until they burst

Question 18

What is turgor pressure?

Answer 18

The force that presses the cell membrane of a plant cell to its cell wall

Question 19

What is plasmolysis?

Answer 19

When the plant cell loses water to a solution of lower water potential, and becomes flaccid

Question 20

Define active transport

Answer 20

The movement of particles through a cell membrane from a region of lower concentration to a region of higher concentration (i.e. against a concentration gradient), using energy from respiration

Question 21

Why is active transport so important?

Answer 21

It is a process for movement of molecules or ions across membranes, including ion uptake by root hairs

Question 22

What do protein carriers do?

Answer 22

They move molecules or ions across a membrane during active transport

Question 23

Describe how active transport plays a role in the uptake of mineral ions by plants

Answer 23

When the concentration of an ion is greater inside the cell than in the soil water, the plant has to use active transport for ion uptake

Question 24

Describe how active transport plays a role in the uptake of glucose by animals

Answer 24

When the concentration of glucose in the blood is higher than in the gut lumen, epithelial cells will need to use active transport to absorb glucose