All of the following statements about enzymes are true EXCEPT:
Isoenzymes are different enzymes catalysing the same chemical reaction - option b is correct. Allosteric regulators bind to a site other than the active site - option c is correct. Translational regulation means inhibiting/activating the synthesis of enzyme/protein (protein translation) to stop/increase the reaction. It takes time and hence is a long term regulation method. - option d is also correct. On the other hand allosteric regulation work instantaneously. Multienzyme complexes greatly increase the rate of reactions. So, option a is wrong statement. It is impoant to differentiate multifunctional enzyme and multienzyme complex. Multifunctional Enzyme Multi enzyme complex Enzymes that contain more than one enzymatic activity (active site) within a single polypeptide chain. Stable, non-valent assembly of different enzymes involved in consecutive reactions of a metabolic pathway. e.g. Fatty acid synthase e.g. PDH complex
Multienzyme complexes greatly reduce the rates of reactions
Isoenzymes differ in their amino acid sequence
Allosteric regulators do not bind to the active site of the enzyme
Translational regulation is method of long term regulation of enzymatic activity
Enzyme basics and serine proteases