Enzymes 2024 PDF

Each year over 500 tons of protease enzymes are added to laundry detergents to break down proteins such as the pizza stains on your shirt. These enzymes are produced by bacteria grown in huge stainless steel tanks.  ENZYMES ✫ are proteins that speed up chemical reactions by lowering acti...

Each year over 500 tons of protease enzymes are added to laundry detergents to break down proteins such as the pizza stains on your shirt. These enzymes are produced by bacteria grown in huge stainless steel tanks.  ENZYMES ✫ are proteins that speed up chemical reactions by lowering activation energy (Ea). ✫a.k.a. biological catalysts b/c the are NOT consumed in the reaction. ✫ The induced fit model suggests that the active site can change shape to suit the particular substrate. ✫ names of enzymes end in “ase” (i.e. lipase)  ACTIVATION ENERGY ✫ Ea is an initial input of energy required to break down large molecules.  HOW DO ENZYMES LOWER EA? 1. Enzymes bring substrate 2. Enzymes destabilize the together and position them substrate (by reducing or correctly. oxidizing - transferring electrons to or from the substrate so it is more likely to react. ENZYMES are held together by several bonds: Factors such as high temperature, low pH (acid), high pH (base) and salts (NaCl, CuCl2, K3PO4) can break these bonds and denature the enzyme. Denaturation Denaturation is the breaking of the bonds that hold the enzyme together in its three-dimensional shape It can be caused by: ➔ Cold temperature: reduce kinetic energy so molecules move slowly = fewer collisions between enzyme and substrate = low reaction rate ➔ Heat: breaks hydrogen, ionic bonds and hydrophobic interactions of the enzyme, which changes the shape of the active site. ➔ pH: the presence of extra H+ ions (in an acidic solution) or OH- ions (in a basic solution) disrupt ionic and hydrogen bonds holding the 3D structure of the enzyme. ➔ Salt: High salt concentrations can disrupt the ionic bonds holding the 3D structure of the enzyme.  a) Enzyme work best under optimal temperature. when temp is too low, enzymes when temp is too high, hydrogen become rigid AND substrate bonds, ionic bonds and molecules slow down so their rate of hydrophobic interaction break and collision with enzyme decreases enzymes denature As temperature rises, the kinetic energy of molecules increases, leading to more frequent and forceful collisions between enzymes and substrates. This results in faster reaction rates. b) Enzyme work best under optimal pH. when pH is low, excess H+ disrupt hydrogen bonds, ionic bonds and hydrophobic interactions in enzymes when pH is high, H-bonds and ionic bonds are disrupted and enzyme denatures b) What the optimal pH of pepsin? amylase? c) Increasing substrate concentration increases enzyme activity only up to a point. c) Increasing substrate concentration increases enzyme activity only up to a point. plateau/ saturation point d) Adding more enzymes increases the rate of enzyme activity. d) Adding more enzymes increases the rate of enzyme activity. As more enzymes are added, the rate of reaction will continue to increase. Rate of reaction will only reach plateau, if there is no more substrate available.  e) High inhibitor concentration decreases enzyme activity. ✧ Inhibitors: molecules that stop the enzyme from working ✧Two types of inhibition: Can we reverse any of the inhibition? Which one? How so?  f) Presence or absences of cofactors & coenzymes can affect enzyme activity. ✧Cofactors: inorganic ions ((i.e. Ca2+, Zn2+, Mg2+) needed for an enzyme to work. ✧ Coenzyme: other enzymes (organic) needed to turn an enzyme on. ALLOSTERIC REGULATION ✧Allosteric Regulators: enzyme receptor sites away from the active site ✧ Activators: change shape of the enzyme so the substrate can bind ✧ Inhibitors: change shape of the enzyme so substrate CANNOT bind  Animation FEEDBACK INHIBITION ✧ The product made by the reaction of the enzyme with the substrate blocks the function of the enzyme ✧ This can be done allosterically ✧ When the product is in high concentration it can shut off the enzyme function ✧ As the product is used/degraded, its concentration drops, freeing the enzyme to continue its function