Structure and functions of living organisms - movement of substances in + out of cells

Question 1

What is diffusion

Answer 1

The movement of particles from a high concentration gradient down the concentration gradient to an area of lower concentration until they are evenly spread and the concentration is the same

Question 2

What is osmosis

Answer 2

The movement of water particles from an area of high water potential to a lower water potential through a partially permeable membrane

Question 3

What is Active Transport

Answer 3

Active transport is the movement of substances against the concentration gradient using ATP (energy)

Question 4

What factors effect the rate of movement in and out of cells and why (for some)

Answer 4

Surface area to volume ratio (bigger = more) - more area to enter into
Distance particle is travelling
Concentration gradient
temperature - give particles more kinetic energy so increases net movement

Question 5

What does partially permeable mean

Answer 5

It only allows smaller particles such as water through but not larger molecules like starch or salt

Question 6

What does a high water potential mean

Answer 6

A dilute solution. contains a high concentration of water molecules and is likely to move to equilibrate
(low water potential is the opposite)

Question 7

Practical: Investigate diffusion and osmosis using living and non-living systems

Answer 7

https://www.savemyexams.com/igcse/biology/edexcel/19/revision-notes/2-structure-and-function-in-living-organisms/movement-of-substances-into–out-of-cells/2-17-practical-investigating-diffusion–osmosis/