Biology Notes Biology & Biochemistry Part 5 Pages 50-56

Standards 1.8 Describe the structures of proteins and amino acids. Explain the functions of proteins in living organisms. Identify some reactions that amino acids undergo. Relate the structure and function of enzymes. 1.9 Explain the role of enzymes as catalysts that lower the activation energy of biochemical reactions. Identify factors such as pH and temperature, and their effect on enzyme activity.

Essential Question 1. Why are enzymes important to us and what influences their actions?

I. Chemical Reactions Chemical Reaction = a process that changes one set of ___________ into another In a chemical reaction, chemical ________ must be broken and new ________ formed reactants = the chemicals that ______ the reaction and undergo transformation chemicals bonds bonds enter

products = the chemicals that _____ the reaction e.g. exit

II. Speeding Chemical Reactions energy Activation energy = the amount of ________ required to ______ a chemical reaction start

A. Catalysts & Enzymes Catalyst = any substance that _______ up a chemical reaction catalysts lower the amount of __________ energy needed for a reaction to ______ Enzyme = a type of protein that acts as a __________ for specific chemical __________ speeds activation begin catalyst reaction

enzymes lower the amount of __________ energy in a chemical reaction e.g. activation

Enzymes are named for the __________ reaction they act as a _________ on enzymes usually end in ______ e.g. chemical catalyst - ase lipase = acts on lipids protease = acts on proteins

B. The Lock & Key Model: How Enzymes Work the enzyme is the _______ and has a specific _______ where only certain substrates will fit substrate = the reactants of a chemical _________ on which the enzymes will act upon the substrate or _____ will fit into the reaction at the ________ site e.g. “lock” shape reaction “key” active see page 56

C. Enzymes Denatured Denaturization = the destruction of an _________ denaturization can occur through changes in _____________, pH, pressure, or other ______________ called inhibitors if enzymes are ___________, they can lose their structure and cannot ___________ enzyme temperature chemicals denatured function