Question

1.When a proton is moved during a reaction, what type of catalysis is occurring? Which amino acids would be able to perform this type of catalysis? What type of catalysis utilizes a nucleophile? What is necessary for metal ion catalysis to occur? How do enzymes work? How are enzymes different from other catalysts?

Answer 1

1. When a proton is moving during a raction. It could be either acid catalysis ar base catalysis. where acid is the proton donor and base is the proton acceptor.

2. Acidic or basic amino acids and polar amino acids would be able to perform acid-base cataysis..

3. Base catalysis utilises nucleophile.

4. To occur metal ion catalysis a stable chelate complex with the substrate.

5. Enzyme can accelerate a reaction by following way

a. It can rearrange the reacting groups in a proper orientation,

b. Stabilises the transition state and intermediates by hydrogen bonds, van der Waals attaraction and electrostatic interactions.

c. It can provide a alternative pathway for the reaction.

d. It can destabilised the substrate to reduce the energy required to reach the transition state.

6. Difference between enzyme and other catalysts

a. Enzymes are biocatalyst , they are high molecular weight globular prteins only, but not all catalysts are proteins or have high molecular weight.

b. Enzymes are highly specific can form large amount amount products, but other catalysts are not so specific.

c. Enzymes works only in mild conditions, i.e. in low tempereture or in particular pH. other catalyst works only under high tempereture and pressure.

d. Enzymes are synthesized by ribosomes in living cells. but other catalysts are not synthsized in living cell.

e. Enzymes can be regulated by concentration of the substrate or by adding other molecules.

f. Enzymes are always organic but other catalysts may or may not be organic.