Enzymes

• Active sites have specific shapes to fit their corresponding substrates.
• When the substrate enters the active site, it undergoes chemical change (catalysis).
• The active site of an enzyme has a specific shape that fits only one type of molecule, called its substrate.
• Factors that increase metabolism or biological processes can raise kcat, decrease Km or both, resulting in a higher catalytic efficiency (kcat/Km).
• Enzyme activity is often modeled by the Michaelis-Menten equation which relates an enzyme's rate of turnover (kcat), affinity for its substrate (Km), and substrate concentration ([S]).
• Enzyme-substrate complex is formed when the substrate binds to an enzyme.
• Enzyme kinetics aims to determine how the rates of enzyme-catalyzed reactions are affected by factors such as temperature, pH and substrate concentration.
• Enzymes can also be classified based on their mechanism of action, such as hydrolases that catalyze hydrolysis reactions and oxidoreductases that catalyze oxidation-reduction reactions.
• Enzyme inhibitors can either decrease or completely stop the activity of enzymes.
• Enzyme-substrate complex formation is reversible, but the enzyme catalyzes the reaction by lowering the activation energy required for the reaction to occur.
• The active site of an enzyme has a complementary shape that fits its substrate like a lock and key.
• An enzyme's active site can be altered through mutations or chemical modifications, affecting its ability to bind with certain molecules.
• Enzyme-substrate complex is formed when an enzyme binds with its substrate.
• Enzyme-substrate complex formation is reversible, but the enzyme catalyzes the reaction by lowering the activation energy required for the reaction to occur.
• Enzymes are biological catalysts that speed up biochemical reactions without being used up or changed themselves.
• The product(s) are released from the enzyme-product complex as the reaction proceeds.
• Enzymes can be inhibited by competitive or noncompetitive inhibitors.
• Enzymes lower activation energy by providing a pathway with less energy barriers than the uncatalyzed reaction.
• Enzymes are proteins with specific three-dimensional structures that allow them to bind to particular substrates and facilitate biochemical reactions.
• Increasing temperature increases the frequency of collisions between reactants but also causes denaturation of proteins.
• Enzymes lower activation energy by bringing reactants together and stabilizing transition states.
• Enzymes increase rate of reaction by increasing forward reaction rate constant kf and decreasing reverse reaction rate constant kr.
• Products are released from the enzyme once they dissociate from the ES complex.
• Enzymes work best at optimal pH levels and temperatures.
• There are two types of inhibitors: competitive and noncompetitive.
• Allosteric regulation involves regulatory proteins that interact with allosteric sites on the enzyme, changing its conformation and affecting its activity.
• The Michaelis constant (Km) represents the substrate concentration at half maximum velocity.
• Competitive inhibition occurs when the inhibitor competes with the substrate for binding sites on the active site of the enzyme.
• Substrate concentration determines whether the reaction will be limited by the availability of substrate or the ability of the enzyme to process it.
• Inhibitors can either compete with the substrate for binding at the active site (competitive inhibition) or bind elsewhere on the enzyme (non-competitive inhibition).
• pH affects the charge distribution on amino acid side chains, affecting their interactions with other charged groups.
• Denatured enzymes lose their ability to function as catalysts.
• Active sites are specific regions within proteins where enzymatic reactions take place.
• Cofactors are nonprotein molecules that assist enzymes in carrying out chemical reactions.
• Competitive inhibition occurs when another molecule competes with the substrate for binding at the active site of the enzyme.
• Feedback inhibition occurs when end products of a pathway act as negative regulators of earlier steps in the same pathway.
• Coenzymes are organic cofactors derived from vitamins that participate directly in biochemical reactions.
• Active sites are specific regions on an enzyme where substrates bind.
• Noncompetitive inhibition involves the formation of a nonproductive enzyme-inhibitor complex, where the inhibitor does not compete with the substrate but instead blocks access to the active site.
• Increasing [S] increases Vmax until it reaches saturation, where all active sites are occupied with substrate molecules.