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Enzymes

Enzymes. Enzyme in our daily lives. Washing Detergent. Any other uses?. Enzyme. It is a biological catalyst …. Exam Time!!!!. Reward!!!!. Unmotivated. Motivated. Faster. Slow. Reward is the catalyst. Bored. Interested. Catalyst.

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Enzymes

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  1. Enzymes

  2. Enzyme in our daily lives Washing Detergent Any other uses?

  3. Enzyme • It is a biological catalyst….

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

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

  7. Example of Inorganic Catalyst • 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.

  8. Enzyme – Biological Catalyst

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

  10. Enzymes • 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. Enzymes • Clip – Enzymes are proteins

  12. Enzymes • Clip – Enzyme activity

  13. Denaturation of Proteins Recap • When denatured, • Bonds within protein molecules broken • Enzyme changes its shape • Denaturationis caused by • High temperature • Change in pH

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

  15. Enzymes and Digestion

  16. Enzymes and Digestion • 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. Enzyme Names Proteins Maltose ase ase

  18. Characteristics of Enzymes 1. Speed up chemical reactions • Lower activation energy

  19. Characteristics of Enzymes 1. Speed up chemical reactionsDefinition • Activation Energy: Energy required to start the reaction • Reactants: Starting materials for reaction • Products: End materials from reaction

  20. Characteristics of Enzymes 2. Enymes are required in small amounts • Remain unchanged • Reused over and over again • Hence only small amount is required

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

  22. Characteristics of Enzymes 2. Enzymes are specific

  23. Characteristics of Enzymes 2. Enzymes are specificDefinition • Substrates: Substances enzymes act on • Active Sites: “pockets” on enzymes where specific substrates will fit

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

  25. Any Questions?

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