Biomolecules (Biology)

A competitive inhibitor of succinic dehydrogenase is

1. -ketoglutarate
2. malate
3. malonate
4. oxaloacetate

About 98 percent of the mass of every living organism is composed of just six elements including carbon, hydrogen, nitrogen, oxygen and

1. sulphur and magnesium
2. magnesium and sodium
3. calcium and phosphorus
4. phosphorus and sulphur

An organic substance bound to an enzyme and essential for its activity is called

1. isoenzyme
2. coenzyme
3. holoenzyme
4. apoenzyme

The catalytic efficiency of two different enzymes can be compared by the

1. formation of the product
2. pH of optimum value
3. Km value
4. molecular size of the enzyme.

Which one of the following statements regarding enzyme inhibition is correct?

1. Competitive inhibition is seen when a substrate competes with an enzyme for binding to an inhibitor protein.
2. Competitive inhibition is seen when the substrate and the inhibitor compete for the active site on the enzyme.
3. Non-competitive inhibition of an enzyme can be overcome by adding large amount of substrate.
4. Non-competitive inhibitors often bind to the enzyme irreversibly.

Enzymes, vitamins and hormones can be classified into a single category of biological chemicals, because all of these

1. help in regulating metabolism
2. are exclusively synthesized in the body of a living organism as at present
3. are conjugated proteins
4. enhance oxidative metabolism.

Which of the following is the simplest amino acid?

1. Alanine
2. Asparagine
3. Glycine
4. Tyrosine

Nucleotides are building blocks of nucleic acids. Each nucleotide is a composite molecule formed by

1. base-sugar-phosphate
2. base-sugar-OH
3. (base-sugar-phosphate)n
4. sugar-phosphate

Carbohydrates, the most abundant biomolecule on earth, are produced by

1. some bacteria, algae and green plant cells
2. fungi, algae and green plant cells
3. all bacteria, fungi and algae
4. viruses, fungi and bacteria.

With which one of the following enzymes is copper necessarily associated as an activator?

1. Carbonic anhydrase
2. Tryptophanase
3. Lactic dehydrogenase
4. Tyrosinase