Skip to main content
Biology LibreTexts

D. More Complicated Enzymes

Skills to Develop

  • draw Cleland chemical reaction diagrams showing enzyme, substrate, and product interactions for multisubstrate and multiproduct sequential and ping-pong enzyme-catalyzed reactions;
  • draw double reciprocal 1/v vs 1/A plots at different fixed B concentrations for sequential and ping-pong multisubstrate reactions;
  • draw v vs S graphs in the presence and absence of allosteric inhibitors and activators for multi-subunit enzymes that display sigmoidal cooperative behavior (K systems) conforming to the MWC model;
  • differentiate between K and V systems for allosterically regulated enzymes using the MWC model and explain shifts in graphs of v vs S in the presence of allosteric effectors

In reality, many enzymes have more than one substrate (A, B) and more than one product (P, Q). For example, the enzyme alcohol dehydrogenase catalyzes the oxidation of ethanol with NAD (a biological oxidizing agent) to form acetaldehyde and NADH.