5 a day revision B4 - Enzymes Explain the lock and key model. Sketch a graph to show the effect of temperature on enzyme reactions. Explain the lock and key model. Define the terms: Enzyme Active site What is a denatured enzyme and how can it happen? An experiment is carried out using 2 samples of amylase. Sample 1 is first heated to 75C and then cooled to 37C. Sample 2 is cooled to 10C and then heated to 37C. Describe and explain the effect on enzyme activity.

5 a day revision B4 - Photosynthesis A B In which part of the cell does photosynthesis take place? State 3 uses of the glucose produced in photosynthesis. What is the balanced symbol equation for photosynthesis? A plant is placed in the dark for 48 hours. A piece of black paper is then placed over part of a leaf as shown. The plant is left in light for 24 hours and then the leaf is tested for the presence of starch. What chemical would you use to test for starch? What colours would be observed at areas A and B, why? Explain why cacti have fewer stomata than other plants. A B

5 a day revision B4 - Respiration Give 3 differences between aerobic and anaerobic respiration . What is respiration? Give the equation for anaerobic respiration in muscles. Sketch a graph to show the changes in sugar and ethanol concentration as yeast grows. Explain the shape of your graph. What is the role of anaerobic respiration in bread making?

5 a day revision B4 - Life processes and cell structure What type of cells have a cell wall but no nucleus? Respiration is a characteristic of living organisms. State 4 others. The diagram shows a typical animal cell and typical plant cell. Name X and Y. Name and label another structure found in both cells. Complete the table. What features do plant cells have that animal cells do not? Part of plant cell Function Cell membrane Cell wall Cytoplasm Mitochondrion Nucleus

5 a day revision B4 - Diffusion/Osmosis/Active transport Carbon dioxide and oxygen are exchanged between alveoli and nearby capillaries. Which process is taking place? Compare and contrast diffusion and active transport. Define diffusion. How is osmosis different? Some red blood cells were placed in distilled water and some placed in a concentrated salt solution. Describe the changes that would take place. The 4 cells contain different concentrations of glucose. Draw a series of arrows to show how water will move by osmosis between the cells. 0.1% 10% 2% 5%