Enzymes Activator # 25 Choose the “ODD ONE OUT” (write down all choices) Spit out any gum or candy…do not eat anything Enzymes 1. Speeds up chemical reactions 2. Is an example of a carbohydrate 3. Works on a specific molecule 4. Helps cells maintain homeostasis

All of the chemical reactions in a cell makes up the cell’s Metabolism 2 main chemical reactions necessary for life Photosynthesis = the formation of glucose in plants Respiration = the formation of ATP from breaking down glucose In order for a reaction to begin it must, gain a certain amount of energy called activation energy

Most chemical reactions occur too slowly (because of the high activation energy) to be useful to living organisms Special proteins (enzymes) act as catalyst to speed up a reaction by lowering its activation energy Does not increase the production of the product Does not get used or changed in the reaction

Enzymes… Are specific and will only bind to specific molecules (lock-and-key) Are reusable Enzymes are usually named by their substrate (the reactant they bind to) and usually end in –ase -Sucrase -Lactase -Maltase

Enzyme Substrate Joins

The region of an enzyme where the substrate binds is called the active site.

Once the substrate binds to the enzyme, an enzyme-substrate complex is formed The bonds of the substrate are broken The products are produced Video Clip

Enzyme Activity Factors such as pH and temperature can affect enzyme activity Each enzyme is only functional under certain conditions Changing the pH or temperature may cause changes in the shape of the enzyme This enzyme will no longer bind to its substrate

On a sheet of notebook paper, copy down the questions and answer them in complete sentences. What is the function of an enzyme? 2. What type of organic compounds are enzymes? 3. What substance takes part in an enzymatic reaction but is unchanged by the reaction? 4. Sucrase is an enzyme that breaks sucrose down into glucose and fructose. What happens to the chemical bonds in sucrose when it binds to the enzyme sucrase? 5. What could cause a change in the shape of an enzyme? Would the enzyme still work properly? Why or why not?

Homework Enzyme Notes - Notes assignment #8