Question

Describe the characteristics of inorganic and organic catalysts (enzymes), as well as the characteristics that apply only to enzymes.

Explain how and why temperature and pH affect enzyme activity

Explain how enzyme concentration, substrate concentration, and enzyme inhibitors affect the rate of enzymatic activity according to the Michaelis-Menten model.

Answer 1

Answer: inorganic catalyst are those which do not include C,H or O in their structure whereas organic catalysts do. Organic catalysts generally work in biosystems not usually outside. For example: some organic catalysts usually includes enzymes like kinases, invertases, polymerases, hydrolases etc.

Now if we talk about the temperature and pH effect on ezymatic activity as the temperature increases the enzymatic activity increases but with more increasing temp the enzymes start denaturing. At body temperature 37°C there is a gradual increases in activity of the enzyme but as it's increases there is a decrease in the activity of enzyme.

Different enzymes work best at different pH values. The optimum pH of the enzyme can be decided by at which it works normally.For example, intestinal enzymes have an optimum pH of about 7.5. Enzymes in the stomach have an optimum pH of about 2.

Now according to Michaelis menten model,

During enzyme substrate reaction, the initial velocity V₀ gradually increases with increasing concentration of the substrate. Finally a point is reached, beyond which the increase in V0 not depend on the [S]. Michaelis and menten first posyulated that enzyme first combines reversibly with it's substrate to form an enzyme substrate complex in a relatively fast reversible step.

Second step is rate limiting step,the rate of overall reaction must be proportional to the concentration of the ES that reacts in the second step.

The relationship between substrate concentration, [S] and initial velocity of enzyme, V0 has the same general shape for most enzymes.

Enzyme inhibitor can alter the activity of the enzyme and take the place of actual enzymes. Just like competitive inhibitors, uncompetitive inhibitors etc..some take place of the active site and stop the enzymes to bind to their active site..in some cases inhibitors take binds to the bonding sote located near the active site and alter the bonding of the enzyme. And by this the product gets less le more.