Enzymes

Enzymes are… Catalysts – is any substance that works to accelerate a chemical reaction Most enzymes are proteins

How do catalysts speed up reactions? The activation energy in chemistry is the energy needed by a system to initiate a particular process Catalysts decrease activation energy

Lock and Key model

Active Site

Substrate: substance that an enzyme reacts with Active Site: part of the enzyme that reacts or binds to the substrate

Enzyme-Substrate Complex

Enzymes are specific and Complementary Complementary: complement one another; shaped for precise pairing Specific: particular, precise – Only the correct substrate can fit into the enzyme’s active site

Enzymes end in -ase Carbohydrase- breaks down carbohydrates into simple sugars Amylase- breaks down starch Protease – breaks down proteins into amino acids Lipase- breaks down lipids into fatty acids and glycerol

Digestive End products MacromoleculeDigestive End Product CarbohydrateSimple Sugar ProteinAmino Acids Lipid3 fatty acids and glycerol Nucleic AcidNucleotide

Temperature effects enzymes Increasing temperature increases enzyme activity until it reaches an optimum value Increasing temperature past that point denatures the enzyme

Denature shape of the protein is altered through some form of external stress will no longer be able to carry out its cellular function

pH effects enzymes Certain pH value causes optimal enzyme activity Too low or too high pH will denature the enzyme

Enzymes are reused or recycled In a written equation, enzymes appear on both the reactant and product side Substrate + enzyme  enzyme and products reactants products They are not used up They are recycled and being used over and over gain

The function of most proteins depends primarily on the (1) type and order of amino acids (2) environment of the organism (3) availability of starch molecules (4) nutritional habits of the organism

Enzyme molecules normally interact with substrate molecules. Some medicines work by blocking enzyme activity in pathogens. These medicines are effective because they (1) are the same size as the enzyme (2) are the same size as the substrate molecules (3) have a shape that fits into the enzyme (4) have a shape that fits into all cell receptors

The diagram below represents two molecules that can interact with each other to cause a biochemical process to occur in a cell. Molecules A and B most likely represent (1) a protein and a chromosome (2) a receptor and a substrate (3) a carbohydrate and an amino acid (4) an antibody and a hormone