Chemical Reactions And Enzymes Biology Mr. Velekei

Vocabulary Activation Energy Catalyst Coenzyme Enzyme Inhibitor Molecule Product Reactant Substrate

Chemical Reactions and Enzymes

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products)

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy Reactants

Chemical Reactions and Enzymes chemical reaction: process that changes one set of compounds (reactants) into another set of compounds (products) A. example: wood + oxygen  carbon dioxide + water + energy Reactants Products

The elements or compounds produced at the end of a chemical reaction Reactants: The elements or compounds present at the beginning of a chemical reaction Products: The elements or compounds produced at the end of a chemical reaction

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen

Chemical reactions: Always involve changes in the chemical bonds that joins atoms in compounds.

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants Products

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants Products chemical equation: CO2 + H2O  C6H12O6 + O2

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants Products chemical equation: CO2 + H2O  C6H12O6 + O2 Reactants

Chemical Reactions and Enzymes B. example: carbon dioxide + water  glucose + oxygen Reactants Products chemical equation: CO2 + H2O  C6H12O6 + O2 Reactants Products

carbon dioxide + water  glucose + oxygen Reactants Products How many molecules are in a chemical formula/equation? Photosynthesis: carbon dioxide + water  glucose + oxygen Reactants Products chemical equation: CO2 + H2O  C6H12O6 + O2 Reactants Products

6CO2 This Molecule is called…. Number of molecules…. Carbon Dioxide Number of molecules…. 6 Number of Carbon atoms…. Number of Oxygen atoms… 12

6H2O a) This Molecule is called…. Number of molecules…. Water Number of molecules…. 6 Number of Hydrogen atoms…. 12 Number of Oxygen atoms…

Glucose: C6H12O6 b) Glucose or Sugar: Number of molecules…. Number of Carbon Atoms… 6 Number of Hydrogen atoms…. 12 Number of Oxygen atoms…

6O2 c) Oxygen…. Number of molecules…. 6 Number of Oxygen atoms… 12

6CO2 + 6H2O  C6H12O6 + O2 How many TOTAL ATOMS of each element are present on the REACTANTS side of the reaction: Carbon: ___________ Oxygen: _____________ Hydrogen: ____________ 6 18 12

6CO2 + 6H2O  C6H12O6 + O2 How many TOTAL ATOMS of each element are present on the PRODUCTS side of the reaction: Carbon: ___________ Oxygen: _____________ Hydrogen: ____________ 6 18 12

CO2 + H2O  C6H12O6 + O2 6CO2 + 6H2O  C6H12O6 + 6O2 C. Conservation of matter: During a chemical reaction, atoms are not created or destroyed – just rearranged. Therefore, chemical equations must be balanced so there is the same number of atoms on both sides of the equation. chemical equation: CO2 + H2O  C6H12O6 + O2 balanced chemical equation 6CO2 + 6H2O  C6H12O6 + 6O2

Apply what you’ve LEARNED a.) 2 H2O2  2H2O + O2 # of reactant molecules: 2 # of product molecules: 3 What are the molecules: Hydrogen Peroxide Water Oxygen

Apply what you’ve LEARNED b.) 2 H2O2  2H2O + O2 # of reactant atoms: 8 (4 H and 4 O) # of product atoms: 8 (4H, 2O, 2O)

II. Energy in Reactions: Energy is absorbed or released whenever chemical bonds form or are broken.

Chemical reactions that Release energy…. Often Occur Spontaneously (without warning) Example: Explosion gun powder or fireworks EXOTHERMIC

Chemical reactions that Absorb energy…. Will not occur without a source of energy. Example: Instant Ice Packs or Photosynthesis. ENDOTHERMIC

The speed of a reaction depends on whether is absorbs or releases energy.

Chemical Reactions and Enzymes II. The speed of a reaction depends on whether it releases or absorbs energy. Activation energy Products Activation energy Reactants Products Reactants Energy Absorbing Endothermic Energy Releasing Exothermic

Chemical Reactions and Enzymes All reactions require some energy to start: activation energy.

Chemical Reactions and Enzymes All reactions require some energy to start: activation energy. catalyst: substance that speeds up a chemical reaction by lowering the activation energy

Chemical Reactions and Enzymes All reactions require some energy to start: activation energy. catalyst: substance that speeds up a chemical reaction by lowering the activation energy Catalysts found in living things are called enzymes Enzymes are made of Proteins

Chemical Reactions and Enzymes C. Enzymes provide a site where the reactants of a chemical reaction can be brought together

Chemical Reactions and Enzymes C. Enzymes provide a site where the reactants of a chemical reaction can be brought together are not used up or changed during the chemical reaction

Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick)

Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick) reactants: called substrate when they stick to the enzyme

Chemical Reactions and Enzymes active site: part of the enzyme where the reactants bind (stick) reactants: called substrate when they are in a reaction with an enzyme substrate only fits into the active site of the correct enzyme (like a key and lock)

Labeled diagram: Enzyme Active Site Reactants

III. How does an enzyme work? A. reactant binds to the enzyme Reactant stuck to Active Site Active Site Reactants

III. How does an enzyme work? A. Reactant binds to the enzyme Reactant stuck to Active Site Active Site

III. How does an enzyme work? B. reactants converted to product Active Site

III. How does an enzyme work. C III. How does an enzyme work? C. products are released – enzyme is free to bind new reactant Enzyme Product Active Site

A. temperature: destroys the shape of the enzyme (protein) IV. Enzymes only work in specific conditions A. temperature: destroys the shape of the enzyme (protein) B. pH: changes the shape of the enzyme and its active site

Temperature or pH Change: Enzyme Product Active Site No Product Made

IV. Enzymes only work in specific conditions C. inhibitor molecules: block reactant from entering active site

Inhibitor Molecules: Enzyme Product Active Site No Product Made

IV. Enzymes only work in specific conditions D. coenzymes: make enzymes work better

Enzyme: Peroxidase in liver cells Reactants: Hydrogen peroxide Active Site

Enzyme: Peroxidase in liver cells Reactants: Hydrogen peroxide Active Site

Enzyme: Peroxidase in liver cells Products: Water and Oxygen H2O Active Site

Enzyme: Peroxidase in liver cells Products: Water and Oxygen More Hydrogen Peroxide Active Site O2 H2O Product

Substrate Concentration The reaction rate increases until the enzymes become saturated with substrate, and a maximum rate is reached