Which of the following statements is correct regarding enzymes?

All enzymes are chemically speaking:

Give generalised information regarding enzymatic organization.

Study the following statements:
$(a)$ The substrate binds to the active site of the enzyme.
$(b)$ Enzymes isolated from thermophilic organisms get denatured at $50^{\circ}C$.
$(c)$ The active site of the enzyme breaks the chemical bonds of the product.
$(d)$ Prosthetic groups are tightly bound to the apoenzyme.
Select the option which includes all correct statements:

Describe the important properties of enzymes.

Lactic dehydrogenase $(LDH)$,which catalyzes the conversion of pyruvate to lactate,is an example of: