Question

A biological catalyst is essentially
(a) An enzyme
(b) A carbohydrate
(c) An amino acid
(d) A nitrogenous base

Answer 1

Hint: They speed up reactions by bringing reactants together and reducing the activation energy required to start the reaction although they are not changed in the reaction. It is unique in nature and shows a varying degree of specificities, while they are highly specific for a particular substrate.

Complete answer:
- Enzyme Catalysis: These are catalysts in the living system. The rate of any biological event can be altered by substances as enzymes.

These are basically proteins, and catalyst activity is structure explicit.
- Enzyme catalysis is the expansion in the rate of a chemical response by the active site of a protein.
- Enzymes are the macromolecular natural catalysts. These are profoundly particular catalysts significantly quickening both the rate and explicitness of metabolic reaction. All enzymes are insoluble since they exist in the colloidal state. Urease is an enzyme that catalyzes the hydrolysis of urea, which can form ammonia and carbon dioxide.

Additional information: Enzymes are specific in nature and they have a particular shape, consequently, only a specific substrate will fit its active site. There are two theories of enzyme activity: Lock and Key and Induced Fit.  The lock and key theory describe that only a specific substrate will fit a specific active site, much the same as a key fit a lock. Induced Fit, in like manner, expresses that enzymes wrap around substrates, attracted to one another by opposite charges, forming an enzyme-substrate complex. 
So the correct answer is ‘An enzyme’.

Note: Enzymes are incredibly effective and have extraordinary catalytic power, changing around 100 to 10,000 substrate molecules into product every second and continuing from 103 to 108 to multiple times quicker than the uncatalyzed reaction. Enzymes don’t affect the equilibrium constant notwithstanding the increase in the conversion rate of the substrate into the product.