year 10 exchange and transport Flashcards
1
Q
why do substances need to be exchanged
A
to help all organisms survive by exchanging substances such as oxygen and water
2
Q
what substances need to be exchanged in living organisms
A
substances such as water (by osmosis), oxygen (for aerobic respiration) and Urea (a waste product)
3
Q
what is diffusion
A
the overall movement of particles from an area of high concentration to an area of lower concentration (down a concentration gradient)
4
Q
what is osmosis
A
the overall movement of water molecules across a partially permeable membrane (down a concentration gradient)
5
Q
what is active transport
A
the overall movement of particles across a membrane (up a concentration gradient) that uses energy (from respiration)
