Enzymes

• Substrates must be able to reach the active site through diffusion or transport mechanisms.
• Non-competitive enzyme inhibition involves an allosteric effector that changes the conformation of the protein, making it less effective at catalyzing reactions.
• Competitive enzyme inhibition occurs when the inhibitor binds to the active site, preventing substrate binding but not affecting the shape of the active site.
• Enzymes speed up reactions by lowering the activation energy, which leads to a higher frequency of successful collisions between reactants.
• The turnover number of an enzyme represents the maximum number of substrate molecules a single enzyme molecule can convert into products per unit time.
• The turnover number of an enzyme represents the maximum number of substrate molecules a single enzyme molecule can convert into products per unit time.
• Enzyme inhibitors can be competitive or non-competitive.
• The Km determines the affinity of an enzyme for its substrate.
• The rate at which an enzymatic reaction occurs depends on several factors, including substrate concentration, temperature, pH, and enzyme concentration.
• Enzyme-substrate complex formation is reversible, with enzymes being released from the product(s) formed by hydrolysis.
• Increasing substrate concentration increases the rate of reaction until it reaches saturation point (Vmax).
• Competitive inhibitors bind to the same site as substrate molecules but do not react with them.
• Michaelis constant (Km) is defined as the concentration of substrate required to achieve half-maximal velocity.
• Uncompetitive enzyme inhibition is rare and occurs when both the inhibitor and substrate can bind simultaneously to the active site, resulting in a decrease in reaction rate.
• Increasing temperature increases reaction rate until the optimal temperature is reached, beyond which denaturation occurs.
• An enzyme's specificity is determined by its three-dimensional structure, including amino acid sequence, tertiary structure, and quaternary structure.
• Amino acids are joined together by peptide bonds to form polypeptides, with different sequences resulting in unique proteins.
• A low Km indicates high affinity for the substrate, while a high Km indicates low affinity.
• Non-competitive inhibition involves binding of an inhibitor to another part of the enzyme, altering its shape and reducing catalytic activity.
• Competitive inhibition involves binding of an inhibitor to the active site of an enzyme, preventing substrates from binding.
• As substrate concentration continues to rise, there are enough substrate molecules available for all active sites, so adding more does not change the rate of reaction.
• pH affects enzyme activity through changes in ionization state and tertiary structure.