1.6 Diffusion

Question 1

What is diffusion

Answer 1

Diffusion is the spreading out of particles of any substance in a solution or particles in a gas, resulting in a net movement of particles from an area of higher concentration to an area of lower concentration, down a concentration gradient

Question 2

What factors affect diffusion

Answer 2

Difference in concentrations, temperature, and available surface area

Question 3

How to work out net movement

Answer 3

nm = particles moving in - particles moving out

Question 4

Describe the rate of diffusion

Answer 4

If there is a big difference in concentration (large concentration gradient) then diffusion will take place quickly

Question 5

What do cells need

Answer 5

oxygen - respiration
minerals - bones/healthy organs
glucose- respiration
amino acids - making proteins

Question 6

Explain why diffusion takes place faster when there is an increase in temperature

Answer 6

Heating makes particles move more quickly speeding up diffusion as particles collide more often and harder and spread out faster

Question 7

What is a concentration gradient?

Answer 7

The difference between two areas of concentration. Diffusion occurs down a concentration gradient

Question 8

What do cells need taken away

Answer 8

carbon dioxide

Question 9

Where does oxygen go in diffusion

Answer 9

oxygen -> lungs -> red blood cells -> cells

Question 10

where does glucose go in diffusion

Answer 10

glucose -> small intestines -> blood -> cells

Question 11

where does amino acids go in diffusion

Answer 11

amino acid -> small intestine -> blood -> cells

Question 12

where does minerals go in diffusion

Answer 12

minerals -> small intestine -> blood -> cells

Question 13

where does carbon dioxide go in diffusion

Answer 13

carbon dioxide -> lungs -> blood -> cells

Question 14

Explain why do many cells have folded membranes along at least one surface

Answer 14

Folded membranes provide increased surface area. The greater the surface area, the more diffusion of dissolved substances can take place across it

Question 15

Does diffusion require energy

Answer 15

No, it is a passive process

Question 16

Give examples of diffusion

Answer 16

oxygen moves from a high concentration in the lungs to a low concentration in the blood.

Question 17

Why does diffusion take place?

Answer 17

Because of the random movement of particles

Question 18

Describe the process of diffusion of digested food products from the gut to the bloodstream

Answer 18

Digested food molecules move from gut (high concentration) into the bloodstream (low concentration) down a concentration gradient.
Large surface area of small intestine lining increases rate of diffusion. Rich blood supply maintains concentration gradient.

Question 19

Describe the process of diffusion when carbon dioxide moves from the blood to the lungs

Answer 19

Carbon dioxide moves from blood (high concentration) into air in the alveoli of the lungs (low concentration) down a concentration gradient.
Large surface area of alveoli increases rate of diffusion. Rich blood supply maintains concentration gradient.

Question 20

Describe the process of diffusion when digested food products move from your gut to your bloodstream

Answer 20

Digested food molecules move from gut (high concentration) into bloodstream (low concentration) down a concentration gradient.
Large surface area of small intestine lining increases rate of diffusion.
Rich blood supply maintains concentration gradient.

Question 21

Describe the process of diffusion occurring when male moths track down a mate up to 3 miles away due to the special chemicals produced by the female

Answer 21

Chemicals produced by female moth spread out into air around her down concentration gradient.
Chemicals more concentrated close to female moth (high concentration) than further away (low concentration). Male moth flies up concentration gradient, following chemical to reach
female moth.