enzymes

• what are enzymes: biological catalysts that are generally protein in nature, required in minute quantities, serve to alter (usually is an increase) the speed of a chemical reaction, substrate specific and remain chemically unchanged at the end of the reaction.
• describe the ’lock and key’ hypothesis: the active site is a lock and the substrate is the key. enzymes have specific three-dimensional active site configuration which allows specific substrate molecules with complementary configuration to bind, forming an enzyme-substrate complex. enzymes catalyses the breakdown of substrate molecules resulting in the formation of product molecules which will no longer bind to active site of enzyme
• describe the ’lock and key’ hypothesis (PART 2): product molecules separates from enzyme molecules allowing the chemically unchanged enzyme molecule to catalyse breakdown of another substrate molecule
• describe the effect of low temperature on enzymes: enzymes are inactive and rate of enzyme activity is low. kinetic energy of both enzyme & substrate molecules are low, hence moving slowly and lower chances of successful collisions to form an enzyme substrate complex
• describe the effect of optimum temperature on enzymes: about 37°c, rate of enzyme activity is highest. as the kinetic energy of both enzyme and substrate molecules increases, there is a higher chance of successful collisions to form an enzyme-substrate complex
• describe the effect of beyond optimum temperature on enzymes: enzymes are denatured. bonds that keep the enzyme in the three-dimensional configuration are broken. active site configuration is lost and substrate molecules can no longer fit in. rate of enzyme activity decreases.
• describe the effect of optimum pH on enzymes: rate of enzyme activity is highest.
• describe the effect of below/above optimum pH on enzymes: enzymes are denatured. bonds that keep the enzyme in the three-dimensional configuration is lost and substrate molecules can no longer fit in. rate of enzyme activity decreases