B2.1.3 - Active Transport

Question 1

Define active transport

Answer 1

Movement of particles from low - high (concentration gradient)

Question 2

What kind of process is active transport?

Answer 2

Active, requires energy from respiration (working against gradient)

Question 3

Active transport in root hair cells?

Answer 3

• Takes up water/mineral ions from soil (energy from respiration)
• Mineral ions in higher concentration of cells, diffusion can’t take place

Question 4

Active transport in gut?

Answer 4

• Substances (like glucose or amino acids from food) move from gut into the bloodstream
• Sometimes sugar molecules have lower concentrations in the gut, preventing diffusion
  
  • Active transport is required to push the sugar into the blood p (working against gradient)

Question 5

Describe carrier proteins

Answer 5

Special proteins, span across width of cell membrane
- Particular molecule required binds to particular carrier protein (like an enzyme)
Energy transfers from store to protein so it can change shape/rotate