2. Any other uses? Washing Detergent

3.  It is a biological catalyst….

4. Unmotivated Slow Bored Motivated Faster Interested Reward!!!! Reward is the catalyst.

5.  “Substance which can alter or speed up a chemical reaction, without itself being chemically changed at the end of the reaction”  Speed up chemical reaction  Without being chemically changed

6. catalyst Without Catalyst Slow reaction Needs a lot of energy to start reaction With Catalyst Faster Needs less energy to start reaction

7.  Potassium Chlorate (VII)  Melt during heating and produce oxygen  Reaction is slow  High temperature  Add catalyst manganese (IV) oxide  Reaction is faster  Lower temperature No change to catalyst at the end of the reaction.

9. Enzyme is like a wrench Enzyme remains unchanged. Like wrench, it can be reused over and over again. Enzyme is specific E.g. wrench can only fit bolts of certain sizes. Enzyme speeds up reaction in both directions. E.g. wrench can take things apart or put them together

10.  Catalyse chemical reactions in living cells  Change rate of reaction  Not chemically changed  Catalyse reaction that  Build up complex substances  Break down complex substances  Biological catalysts made of proteins

11.  Clip – Enzymes are proteins

12.  Clip – Enzyme activity

13.  When denatured,  Bonds within protein molecules broken  Enzyme changes its shape  Denaturation is caused by  High temperature  Change in pH Recap

14.  Food molecules  Large  insoluble in water  Cannot diffuse through cell membrane  Need to break down into simpler and smaller molecules  Soluble in water  diffusible

16.  Digestive enzymes  Enzymes that help to digest food  Example  Amylase: digests starch to maltose  Maltase: digests maltose to glucose  Proteases: digest proteins to amino acids

17. Maltose ase Proteins ase

18. 1. Speed up chemical reactions  Lower activation energy

19. 1. Speed up chemical reactions Definition  Activation Energy: Energy required to start the reaction  Reactants: Starting materials for reaction  Products: End materials from reaction

20. 2. Enymes are required in small amounts  Remain unchanged  Reused over and over again  Hence only small amount is required

21. 2. Enzymes are specific  Each chemical reaction is catalysed by a unique enzyme  Lock and Key hypothesis

22. 2. Enzymes are specific

23. 2. Enzymes are specific Definition  Substrates: Substances enzymes act on  Active Sites: “pockets” on enzymes where specific substrates will fit

24.  Heating or change of pH will change the shape of enzyme  Active site changes shape  Loses its uniqueness