Active Transport

Question 1

Explain why the levels of rate of intake of epithelial cells levels of, as concentration increases 3 marks

Answer 1

The movement is through carrier proteins / facilitated diffusion

Rate of uptake is is directly proportional to each other.

As the conc increases levels of equilibrium have been reached so channel / carrier proteins is reached saturation point and have all been used up so conc can’t increase.

Question 2

Water and inorganic ions have important biological functions within cells

Compare and contrast the processes by which water and inorganic ions enter cells

3 marks

This isn’t exactly related to active transport , just don’t know which section to put it in

Answer 2

Comparison: both move down concentration gradient;

2. Comparison: both move through (protein) channels in membrane;
   Accept aquaporins (for water) and ion channels
3. Contrast: ions can move against a concentration gradient by active transport