exchange surfaces (3.1.1.a) Flashcards
can you explain the need for specialised exchange surfaces?
osmosis
the net movement of water molecues from dilute solution to concentrated solution.
diffusion
the movement of molecules from high concentration to low until the concentration of molecules is equal throughout the system.
active transport
the movement of molecules and ions from low concentration to high using energy from respiration.
similarity between osmosis and active transport
both require a semi-permeable membrane.
similarity between active transport and diffusion
both involve the transport of solutes.
similarities between all three processes
- all involve the movement of particles.
- all occur in nature
why is oxygen exchanged?
for aerobic respiration
why are proteins exchanged?
growth and repair
why are fats exchanged?
- to create membranes (therefore creating multicellular structures).
- act as an energy store.
why is glucose exchnaged?
source of energy.
why is water exchanged?
hydration
why are minerals exchanged?
- to maintain water potential
- assist with enzyme action.
what are the 3 waste products created when exchanging materials?
oxygen
carbon dioxide
uruea/ammonia
