An enzyme can be synthesised by chemically bonding together molecules of

The following graph shows the effect of substrate concentration on enzyme activity. What does the $Y$-axis represent?

The enzyme which hydrolyses starch to maltose is:

The enzyme lactase is responsible for the breakdown of lactose into:

The figure given shows the conversion of substrate into product by an enzyme. In which one of the four options,the components of the reaction labelled $a, b, c, \& \ d$ are identified correctly?
$(i)$ Potential energy
(ii) Transition state
(iii) Activation energy with enzyme
(iv) Activation energy without enzyme

Enzymes are best defined as