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Chapter 6

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Chapter 6

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  1. Chapter 6 Enzymes

  2. Metabolic Reactions • Metabolism • All the reactions that happen in the cell • Reactions have two sides • What goes into the reaction  Reactants • What comes out of the reaction  Products Reactants  Products A + B  C + D

  3. Metabolic Pathways • Reactions that happen in cells are a series of linked reactions

  4. Chemicals are changes in a metabolic pathway by Enzymes • An Enzyme is a protein that acts as a catalyst to speed chemical reactions. • The reactants in a enzymatic reaction are called the Substrate Substrate  Product

  5. Where is the enzyme? Where is the Substrate?

  6. Energy of Activation • Enzymes speed up reactions by lowering the reactions Energy of activation • Energy of activation  the energy required to make a reaction occur Which reaction has the Enzyme present?

  7. Enzyme Substrate Complexes Enzyme + Substrate Enzyme Substrate Complex  Enzyme + Product • Active site  The part of the enzyme that fits with the substrate • Enzymes change shape slightly so they can fit together with the substrate better.  this is called Induced Fit Model

  8. Types of Enzymes • Enzymes only complex with a specific substrate so they are named after their substrate • Enzyme names often end with “-ase”

  9. Factors that affect the enzymatic reactions • Substrate Concentration • The greater the substrate  The more reactions • Temperature • As temperature increases  More reactions • If temperature is too high  Enzyme denatures • pH • Every enzyme works at a specific pH

  10. Where would you find these enzymes? Mouth Kidney and Small intestine Stomach

  11. Factors that affect enzyme reactions • Enzyme Concentrations • The more Enzyme the more reactions • The body may want to regulate the reactions so it will prevent an enzyme from working • Competitive Inhibitors • Non-competitive Inhibitors

  12. Competitive Inhibitor • A molecule that is very similar to an enzymes substrate will bind with the active site. But since its the wrong molecule, no product is made

  13. Non-competitive Inhibitor • A molecule binds to an enzyme. But it does not bind to the active site. The molecule changes the shape of the protein so it no longer works. • The enzyme will work when the non-competitive inhibitor leaves

  14. Substrate Non-Competitive Inhibitor Products Enzyme S

  15. Using Enzyme inhibitors the body can regulate how much product is being made • The concentration of the product is always within a certain range • It regulates it by Feedback Inhibition

  16. Heavy Metals and Enzymes • Heavy Metals  Metals that are towards the middle of the periodic table. They are considered poisonous. • Heavy metals will interact with the “R” group of certain amino acids. How would this affect an Enzyme? • When the “R” group is changed then the tertiary structure changes. • If the tertiary structure is changed  The Protein is changed

  17. Are Heavy Metals competitive inhibitors or non-competitive inhibitors? • They are non-competitive inhibitors • Because they are not competition for the active site

  18. Enzyme Cofactors • Some enzymes need an inorganic ion or a organic molecule to help the enzyme function • Cofactors  inorganic ions like zinc or iron • Coenzymes  organic non-protein molecule • Vitamins  are required to help synthesis coenzymes. Some vitamins are coenzymes.

  19. Cofactor

  20. Coenzymes

  21. Coenzyme

  22. So what tells the body to do all of these metabolic reactions? • There is a gland in the body called the Thyroid • The Thyroid releases a hormone called Thyroxine • If this hormone is released it tells the body to increase metabolic functions