Question

1) When considering single molecule vs ensemble kinetics for a simple dissociation reaction such as release of product from an enzyme (E:P <-> E + P), at the single molecule level is the product released at the rate of the rate constant or is it released very rapidly but the lifetime of the E:P state varies from molecule to molecule?

2) What or where in a cell are you likely to find only one-to-two molecules of a substrate?

3) For these one to two molecules, should you approach the kinetics as single molecule or ensemble?

Answer 1

Ans.1.The product is released at the rate of the rate constant. As the rate constant quantifies the rate of a reaction, it is correct to assume that the product is released at the same rate.

Ans.2.The enzyme TEM1-beta shows this kind of behaviour.

Ans.3.The ensemble should be considered because the there is formation of two products thus the average of both should be considered.