The incorrect statement among the following regarding enzyme inhibitors is:

1. They inhibit the catalytic activity of the enzyme.
2. They prevent the binding of substrate.
3. Generally, a strong covalent bond is formed between an inhibitor and an enzyme.
4. Inhibitors can be competitive or non-competitive.

HINT: Drug inhibitors binds via weak forces with enzymes. 
 
Explanation: 
Drugs can block the binding site of the enzyme and present the binding of the substrate or can inhibit the catalytic activity of the enzyme. Such drugs are called enzyme inhibitors.

Drugs inhibit the attachment of the substrate on the active site of the enzyme in two different ways.

(i) Drugs that compete with the natural substrate for their attachment on the active sites of enzymes are called competitive inhibitors.

(ii) However, some drugs do not bind to the active site but bind to a different site of enzyme i.e., the allosteric site which changes the shape of the active site of the enzyme in such a way that the natural substrate cannot recognize it.

Such enzymes are called non-competitive inhibitors.

Generally, a weak bond such as hydrogen bonding, van der, Waals' interactions, etc., is formed between the enzyme and inhibitor.