Decline in the activity of the enzyme hexokinase by glucose $6$-phosphate is caused by

The following statements are the steps in the catalytic action of an enzyme. Arrange them in the correct sequence.
a) The active site of the enzyme, now in close proximity of the substrate, breaks the chemical bonds of the substrate and a new enzyme-product complex is formed.
b) The substrate binds to the enzyme, inducing a change in the active site of the enzyme.
c) The enzyme releases the products of the reaction and the free enzyme is ready to bind to another molecule of the substrate.
d) The substrate binds to the active site of the enzyme.

An average living cell contains about:

In the modern system of nomenclature,which one of the following enzymes occupies the $6^{th}$ position?

$A$ : Non-competitive inhibitors have no effect on $V_{max}$.
$R$ : In non-competitive inhibition,inhibitor and substrate bind at same sites on the enzyme.

Water-soluble and colloidal catalysts made of proteins are: