Exchnaging Substances

Question 1

What is diffusion ?

Answer 1

The spreading out of particles from a area of high concentration to an area of low concentration

Question 2

Name the substances that can diffuse through a cell mebrane

Answer 2

• oxygen
• glucose
• amino acids
• water

Question 3

Name the substance that can’t diffuse through a cell membrane

Answer 3

• starch

- proteins

Question 4

What type of molecules move by osmosis

Answer 4

Water

Question 5

What is osmosis ?

Answer 5

The movement of water molecules across a partially permeable membrane in from aRegion of high concentration to low concentration

Question 6

What is active transport ?

Answer 6

The movement of substances from a lower concentration to high concentration against a concentration gradient

Question 7

What is the difference between diffusion and active transport ?

Answer 7

• Active transport requires energy
• Diffusion is from a high concentration to a low concentration whereas active transport it on the loo concentration to high concentration

Question 8

How are alveoli adapted for gas exchange ?

Answer 8

• large surface are
• thin walls
• good blood supply
• moist lining

Question 9

How are the villi in the small intestine adapted for absorbing digested food ?

Answer 9

• single layer of surface cells

- good blood supply

Question 10

How are leaves adapted to maximise the amount of carbon diode that gets in there cells ?

Answer 10

It is covered in little holes called stomata

Question 11

Where does diffusion happen?

Answer 11

In solutions and gases this is because the particles are free to move about randomly

Question 12

How can we increase the rate of diffusion

Answer 12

• A bigger concentration gradient
• Higher temperature particles have more energy
• bigger surface area

Question 13

What is a partially permeable membrane in?

Answer 13

The membrane with very small holes in it

Question 14

Where is active transport used?

Answer 14

• when mineral ions need to be absorbed into plants through root hair cells
• When sugar molecules need to be absorbed from lower concentrations in the goat to the blood which has a higher sugar concentration

Question 15

How are exchange services adapted to maximise effectiveness?

Answer 15

• thin membrane so there is only a short distance to diffuse
• large surface area so lots of substance can diffuse at once
• Lots of blood vessels to get stuff into and out of the blue quickly

Question 16

How are you gills adapted for gas exchange?

Answer 16

• Large surface area
• covered in Gill filaments which are covered in Lamelle which increases of Surface area even more
• lots of blood can capillaries
• thin surface layer to minimise the distance

Question 17

Other than diffusion I want to processors do you substances move across exchange surfaces?

Answer 17

Active transport and osmosis

Question 18

Name the exchange surfaces in human

Answer 18

Alveoli In the lung and villi in the Smalling intestine

Question 19

Explain how the structure of the villi is related to their function?

Answer 19

• The increased surface area to maximise absorption
• they have a thin wall to reduce distance of diffusion
• they have a good blood supply for the uptake of substances

Question 20

Suggest how the products of digestions move into the blood?

Answer 20

By diffusion down the concentration gradient into the blood

and by active transport against their concentration gradient