Essential Question: How are actions of enzymes important to us? Topic: ENZYMES Essential Question: How are actions of enzymes important to us? Objectives: Explain how enzymes speed up the rate of biochemical reactions by lowering the reaction’s activation energy. Identify and describe the effect of environmental factors on enzyme activity.

Chemical Reactions and Energy Plant and animal cells break down sugars to get usable energy. Cells build protein molecules by bonding amino acids together. Lipids are broken down inside your body. All of this requires energy!!!! Energy is being added when chemical bonds are broken Energy is being release when chemical bonds are formed.

Activation Energy The amount of energy needed to get a reaction started. Exo (out) thermic(heat) Reaction- releases more energy than it absorbs. The extra energy is release as light or heat. Endo (in) thermic Reaction- absorbs more energy than it releases. Extra energy has to be absorb to make up the difference.

Exothermic vs Endothermic

Exothermic vs Endothermic https://youtu.be/L-G7pLufXAo

Enzymes are Catalysts Catalyst- A substance that decreases the activation energy needed to start a chemical reaction, therefore speeding up the chemical reaction. Amt. of activation energy decrease but time it takes for reaction increase. http://en.wikipedia.org/wiki/File:GLO1_Homo_sapiens_small_fast.gif Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

Enzymes are Catalysts Enzymes are catalyst for living things. Enzymes, which are a types of proteins(made of polypeptide chains), speed up chemical reactions. http://en.wikipedia.org/wiki/File:GLO1_Homo_sapiens_small_fast.gif Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

Enzymes are used all over your body! Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

http://upload. wikimedia http://upload.wikimedia.org/wikipedia/commons/thumb/6/6f/Major_digestive_enzymes.png/750px-Major_digestive_enzymes.png Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

Enzymes Structure Each enzyme shape allows only certain reactants to bind to the enzyme. The specific reactants that an enzyme acts on are called substrate. Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

Naming Enzymes Take the name of the substrate the enzyme works on and add the suffix -ase Example: Lactose  Lactase Sucrose  Sucrase Not always the case-some enzymes have the ending –in (pepsin) Life Sciences-HHMI Outreach. Copyright 2009 President and Fellows of Harvard College

Factors that affect enzyme activity Temperature pH Concentration

Enzymes and Temperature Break up

What is the optimum temperature for this enzyme? 40◦C 30◦C 50◦C

Enzymes and pH

What is the optimal pH? 4 10 8

Which enzyme would you expect to show a higher activity at pH 7? Fumarase Arginase Neither

Enzymes and Concentration

Enzymes and Concentration