Diffusion

Question 1

What is diffusion

Answer 1

The passive movement of molecules or (ions) from a region of high concentration to an area of low concentration….(Concentration Gradient) until… the molecules or ions are evenly distributed in each region

Question 2

What is the concentration gradient

Answer 2

The difference between the concentration of molecules or ions in two regions

Question 3

What factors influence diffusion?

Answer 3

1. The temperature
2. Concentration gradient
3. Size of molecule or ion
4. Nature of the molecule
5. ​The thickness of the cell membrane
6. The surface area of the cell membrane
7. The distance between the two areas
8. The number of protein channels and carrier molecules there are in the membrane

Question 4

How does temperature influence the rate of diffusion

Answer 4

• The higher the temperature, the greater the rate kinetic energy and therefore the greater the rate of diffusion
• Temperature has a low impact on the rate of the diffusion in reality

Question 5

How does the size of the molecule or ion influence the rate of diffusion

Answer 5

• The smaller the molecule of ion the faster the rate of diffusion typically

Question 6

How does the thickness of a cell membrane influence the rate of diffusion

Answer 6

• The thinner the membrane the faster the rate of diffusion typically e.g. alveoili

Question 7

How does the distance between the two areas influence the rate of diffusion

Answer 7

• The shorter the distance between the two areas the faster the rate of diffusion typically

Question 8

How does the surface area of a cell membrane influence the rate of diffusion

Answer 8

• The larger the surface area of a cell the faster the rate of diffusion typically e.g. spongy mesophyll cells of a leaf

Question 9

How does the number of protein channels and carrier molecules influence the rate of diffusion

Answer 9

The larger the number of protein channels and carrier molecules the faster the rate of diffusion

Question 10

What factors result in a fast rate of diffusion

Answer 10

The rate of diffusion is rapid when the…

• Temperature is high
• Molecules or ions are small
• Molecules are fat soluable
• and or Non polar
• There is a high concentration gradient
• between 2 areas which are close to each other
• The cell membrane is thin and has A large suface area
• Which has a large number of protein channels and carrier molecules in the membrane