2. HIGH concentration LOW concentration A difference in concentration between 2 areas is called a CONCENTRATION GRADIENT . What effect might the gradient have on speed of diffusion?

3. Fast Steep concentration gradient Shallow concentration gradient Rate of Diffusion Draw both sets of diagrams, write how the rate of diffusion changes when the concentration gradient changes Slow

5. ? Think – Pair - Share

6. The particles are separate when first put together. They slowly start to mix due to their random motion. The particles are now nearly fully diffuse. The particles are fully diffuse. Draw the diagrams next to each other and copy the captions Has diffusion stopped completely? Explain your answer

11. Oxygen in inhaled air diffuses through the lungs and into the bloodstream. The oxygen is then transported throughout the body. Carbon dioxide is the waste gas produced by respiration. Carbon dioxide diffuses from body tissues into the bloodstream and is exhaled via the lungs. Where does gas exchange take place in the lungs?

12. deoxygenated blood (from body tissues) oxygenated blood (to body tissues) air in/out Alveoli are the tiny air sacs at the end of the bronchioles, in which gas exchange occurs. alveolus capillary red blood cell

15. Digestion breaks down large food molecules into smaller molecules such as glucose, amino acids and fatty acids that can be easily absorbed. Small food molecules are usually absorbed in the small intestine, diffusing across the intestine wall and into the bloodstream.

16. blood vessels capillary network Villi small intestine

18. A synapse is a junction between two neurones across which electrical signals must pass. Neurotransmitter molecules diffuse from vesicles towards the neurotransmitter receptors, moving from an area of high concentration to low concentration.

21. How does the placenta work? umbilical cord umbilical artery umbilical vein

23. Label the leaf