Enzymes
What are Enzymes? Enzymes are proteins Used by the cell to speed up reactions. Are biological catalysts Remain unchanged by the reaction Are reusable
How do enzymes Work? Enzymes work by weakening bonds which lowers activation energy
Enzymes Enzymes are proteins with a 3 dimensional shape. Their specific shape determines the substrate that it works with. Substrates are the substances that the enzymes act upon. Lipase acts on lipids. Maltase acts on maltose. Protease acts on proteins. Substrates Enzymes
Step by Step The substrate binds to the enzyme at the active site Only certain substrates can fit the active site Enzyme-substrate complex forms Substrate reacts to form product Product is released
(substrate begins reaction) Substrate binds to the enzyme at the Active Site Enzyme substrate complex forms (substrate begins reaction) Product is released Enzyme can be used again
Enzymes The rate of enzyme activity depends not only on its 3 dimensional shape, but it also depends on other factors. temperature pH concentration inhibitors
Temperature Little activity at low temperature Rate increases with temperature Most active at optimum temperatures (usually 37°C in humans) Enzymes denature (change shape) at high temperatures
Temperature What is the optimal temperature for enzyme A? ________ What is the optimal temperature for enzyme B? ________ Knowing that room temperature is approximately 22 degrees Celsius, which enzyme would work best in your body? __________ 38oC 62oC A
pH Maximum activity at optimum pH Narrow range of activity Most lose activity in low or high pH
pH What is the optimal pH for the enzyme found in your stomach ? Gastric Protease Intestinal Protease What is the optimal pH for the enzyme found in your stomach ? What is the optimal pH for the enzyme found in your intestine? What organic substance are both of these enzymes digesting? 3 7.8 Proteins
Concentration Increasing substrate concentration increases the rate of reaction Maximum activity reached when all of enzyme combines with substrate
Inhibitors Competitive inhibitor Substrate Competitive: are chemicals that resemble an enzyme’s normal substrate and compete with it for the active site. Enzyme Substrate Competitive inhibitor
Inhibitors Substrate active site altered Enzyme Noncompetitive: Inhibitors that do not enter the active site, but bind to another part of the enzyme causing the enzyme to change its shape, which in turn alters the active site. Enzyme Noncompetitive Inhibitor Substrate active site altered
Competitive Inhibition Noncompetitive Inhibition Inhibitors Competitive Inhibition Noncompetitive Inhibition
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