1 / 16

Enzymes

Enzymes. Chemical Reactions . Chemical bonds connect atoms to make molecules . Chemical reactions can do two things: They can join atoms to make molecules. They can break bonds in molecules.

grady
Download Presentation

Enzymes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Enzymes

  2. Chemical Reactions • Chemical bonds connect atoms to make molecules. • Chemical reactions can do two things: • They can join atoms to make molecules. • They can break bonds in molecules. • The sum of all the chemical reactions that take place within a cell is referred to as the cell’s metabolism. • In order for chemical reactions to take place, enzymes must be present to help speed up the reaction.

  3. Chemical Reactions The molecules or atoms at the beginning of a chemical reaction are called the reactants. The materials produced by the chemical reaction are called products. 2H2 + O2 2H2O Reactants Product

  4. Enzymes are PROTEINS The building blocks of proteins are called amino acids. Chains of amino acids are folded and joined together to give each protein a specific shape. A protein’s function (job) depends on its shape. Proteins will stop working if temperature or pH damage their shape.

  5. Introduction to Enzymes • Enzymes are proteinsthat act as biological catalysts. • speedup chemical reactions in living cells.

  6. Structure and Function of Enzymes A substrate is the molecule that the enzyme changes. Each enzyme has an active site which is the place where the enzyme and substrate attach.

  7. Structure and Function of Enzymes • The shape of enzymes allow them to: • Recognize their substrates • Join with their substrates and perform a chemical reaction.

  8. Structure and Function of Enzymes During a chemical reaction, the enzyme helps the reactant turn into product, however, the enzyme is not changed. Enzymes can be used over and over again. Reactant Product Enzyme No change in the shape of enzyme.

  9. Enzyme Specificity • Enzymes are very specific. This means that each enzyme can only work on one substrate. • For example: • 1. Maltase only breaks down maltose (a carbohydrate). • 2. Lipase only works on certain lipids. • 3. Protease only works on certain proteins. • Does a specific enzyme work on more than one substrate? • NO!!!

  10. Enzyme Specificity Therefore you need thousands of different enzymes for the thousands of differentchemical reactionsin your body. The names of many enzymes (Pepsin, Trypsin, Ptyalin and chymotrypsin) usually end in ase or in.

  11. Enzyme Specificity The diagram below shows the lock and key modelof how enzymes work on a specific substrate. Just like every lock has one type of key that opens it, every substrate has one type of enzyme that works on it.

  12. How Enzymes Work • Lower activation energy • Energy that is needed to start a chemical reaction

  13. Enzymes and Their Environment Most cells function best within a narrow range of temperature and pH. At very low temperatures, enzymes work too slow.

  14. Enzymes and Their Environment • At high temperatures or extremes of pH the enzymes losetheir shape. • What would happen if a key lost its shape? • It wouldn’t turn or fit in the hole. • What will happen if an enzyme lost its shape? • It wouldn’t recognize or bind with it’s substrate.

  15. Enzymes and Their Environment When an enzyme loses its shape and can no longer work correctly, it has been denatured.

  16. Enzyme Practice Come to the board and label each part of the reaction.

More Related