Chemistry of Life Enzymes

I can explain the role of enzymes Objective I can explain the role of enzymes

Lactose Intolerance

Reactions Cells build polymers from monomers Cells break down polymers to release monomers The process in which molecules are built and broken down are called chemical reactions

Hydrogen peroxide breaks down to water and oxygen Example Reaction Hydrogen peroxide breaks down to water and oxygen

Reaction Rates Chemical reactions are involved in processes ranging from contracting muscles to digesting food. A huge number of reaction take place at the same time The rate at which chemical reactions take place is important.

Catalyst The rate of chemical reaction is increased by a catalyst. Catalyst: a chemical that speeds up chemical reactions In living organisms a protein catalysts, an enzyme, is used to speed up reactions.

Example Catalyst Catalase is the enzyme that breaks down hydrogen peroxide

Enzyme Enzyme: an organic molecule that speeds up a reaction without being changed Enzymes make a reaction happen faster and with less energy Enzymes remain unchanged so they can be used repeatedly Most enzymes are proteins Enzyme

How Enzymes Work Enzymes work by lowering the activation energy of a chemical reaction Activation Energy: the minimum amount of energy required to start a reaction.

How Enzymes Work Enzymes lower the activation energy by reducing the amount of energy need for reactant to come together. Enzymes bind the reactant molecules (substrates) tightly together. The place on the enzyme where the substrates are bound is called the active site.

How Enzymes Work Enzymes bind the reactant molecules (substrates) tightly together. The place on the enzyme where the substrates are bound is called the active site.

Lock and Key Each enzyme is specific to one substrate molecule The lock and key hypothesis states that the active site specifically matches the shape of the substrate molecule

Factors that Influence Enzymes pH – most enzymes work the best at a pH between 6-8 Heat – adding heat boosts energy which increases the rate of the reaction Some enzymes will permanently change (denature) if the conditions are too severe.

Importance of Enzymes Enzymes help digest food – they break down macromolecules into smaller molecules the body can use.

I can explain the role of enzymes Objective I can explain the role of enzymes