graphs of transport

simple diffusion

Rate of uptake and oxygen concentration straight line

The rate of oxygen uptake into roots is directly proportional to its concentration

What does this imply

As the concentration gradient between the inside and the outside of the cell increases the oxygen diffuses in proportionally faster

Facilitated diffusion graph

Straight line at the start then plateaus - rate of uptake and amino acid concentration

Describing the graph

The rate of uptake is directly proportional to amino acid concentration at the start but reaches a plateau - at one point there is no increase in the rate of uptake

Why

The carriers are occupied and their numbers has become limiting

Active transport

Concentration difference across membrane, rate of uptake , respiratory inhibitor added increases at the start then plateaus then decreases

Describing the graph

The higher the concentration difference across a membrane the rate of uptake increases and reaches a plateau at which the carrier proteins are saturated

Addition of cyanide which is a respiratory inhibitor

The rate of uptake is reduced as it will prevent aerobic respiration and the production of ATP in the mitochondria, without ATP active transport cannot occur so the cyanide reduces active transport

What other graph shows that active transport is used

If as the oxygen concentration increases (there is more oxygen available) the rate of uptake increases as the oxygen would have increased the production of ATP by aerobic respiration