osmosis- across cell membrane

Question 1

osmosis is diffusion of water molecules
explain this

Answer 1

• osmosis is the diffusion of water molecules across a partially permeable membrane, from an area of high water potential (higher concentration of water molecules) to an area of low water potential

Question 2

what is water potential

Answer 2

likelihood of water molecules to diffuse into or out of a solution

Question 3

what water has the highest water potential

Answer 3

pure water, all solutions have a lower water potential than water

Question 4

what does it mean if two solutions are isotonic

Answer 4

they have the same water potential

Question 5

factors effecting the rate of osmosis

Answer 5

• water potential gradient (faster if the water potential gradient is higher)
• thickness of the exchange surface
• surface area of the exchange surface

Question 6

how can you investigate water potential

Answer 6

using serial dilutions to find the water potential of potato cells

Question 7

how do you find the water potential of the potato cells

Answer 7

calculate the percentage change in mass
- use the results to make a calibration curve showing the percentage change

Question 8

what does a gain in mass mean of the potatos

Answer 8

the potato chips will gain water and therefore mass in solutions with higher water potential than the chips

Question 9

what will a reduction in mass mean of the potato chips

Answer 9

the potato chips will lose water in solutions with lower water potential than inside the potato

Question 10

does osmosis require energy

Answer 10

no