Biology Notes Biochemistry Part 4 Pages 50-56

Standards 2.7 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. 2.8 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. Reactions that Build & Break Polymers Most nutrients as well as nucleic acids are also _______________ or giant molecules. Once food is taken into the body, these large molecules are _______ down and used to build other ___________ macromolecules broken molecules

A. Building Polymers (Macromolecules) Dehydration Synthesis = the process that occurs to make __________ by removing _______ and forming _________ bonds between ___ monomers polymers water covalent 2

This process occurs to join: amino acids into _________ nucleotides into ____________ monosaccharides into _____________ which can join together to form polysaccharides proteins nucleic acids disaccharides

B. Breaking Polymers (Macromolecules) Hydrolysis = the process that occurs to break the _________ bonds in polymers by adding ______ and results in smaller __________ in the body this is known as _________ covalent water monomers digestion

This process occurs to break down: proteins into _______ acids nucleic acids into ____________ polysaccharides into ______________ which can be broken down to _________________ amino nucleotides disaccharides monosaccharides

III. 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