MCQs On Biomolecules

1.The fastest enzyme is

1. DNA polymerase
2. Pepsin
3. Carbonic anhydrase
4. DNA gyrase

Feedback: Carbonic anhydrase is one of the fastest enzymes while lysozyme is the slowest enzyme. One molecule of carbonic anhydrase enzyme can hydrate 106 molecules of CO2 per second. This reaction is 107 times faster than reactions that take place in the absence of carbonic anhydrase.

2. Most abundant biomolecule on earth?

1. Carbohydrates
2. Mineral salts
3. Proteins
4. Lipids

3. Haemoglobin has

1. Primary structure
2. Secondary structure
3. Tertiary structure
4. Quaternary structure

Feedback: Hemoglobin has a quaternary structure. It consists of two pairs of different proteins, designated the α and β chains. There are 141 and 146 amino acids in the α and β chains of hemoglobin, respectively. As in myoglobin, each subunit is linked covalently to a molecule of heme.

4. Koshland’s theory of enzyme action is known as

1. Induced fit theory
2. Reduced fit theory
3. Lock and key theory
4. Enzyme coenzyme theory

Also Read: MCQs On Vitamins

5. β-oxidation occurs in

1. Nucleus
2. Cytoplasm
3. Chloroplast
4. Mitochondria

Feedback: Inside mitochondria beta oxidation of fatty acids takes place in which two carbon atoms are removed in the form of acetyl-CoA from acyl-CoA at the carboxyl terminal. The bond is broken between the second carbon/beta carbon and the third carbon/gamma carbon, hence the name beta oxidation. In mammals, beta-oxidation occurs in both mitochondria and peroxisomes, whereas plants and most fungi harbor the beta-oxidation cycle only in the peroxisomes.

 6. The most common secondary structure of proteins is

1. β-pleated sheet
2. α-helix
3. β-pleated sheet parallel
4. β-pleated sheet non-parallel

7. Mineral associated with cytochrome is

1. Mg
2. Cu and Ag
3. Fe
4. Cu

Feedback: Cytochromes are iron-containing protein. It helps in the generation of ATP by electron transport chain. It helps in the transfer of electrons by oxidation and reduction. The iron present in the cytochrome gets converted into Fe2+ into Fe3+. It also transfers electrons between complex III and complex IV during electron transport chain. Cytochrome oxidase is a metalloprotein, integral to the mitochondrial membrane, which contains copper and iron.

8. The term enzyme was coined by

1. Urey Miller
2. Pasteur
3. Kuhne
4. Buchne

Feedback:  Early enzymology-demystifying life. In 1833, diastase (a mixture of amylases) was the first enzyme to be discovered, quickly followed by other hydrolytic enzymes such as pepsin and invertase, but the term enzyme was only coined in 1877 by Wilhelm Kühne.

9. Which biomolecule is distributed more widely in a cell?

1. DNA
2. Chloroplast
3. RNA
4. Spaherosomes

Also Read: MCQs On PCR

10. Most abundant RNA in the cell

1. rRNA
2. mRNA
3. tRNA
4. tRNA threonine

Feedback: Ribosomal ribonucleic acid (rRNA) is the most abundant type of RNA. It develops the material inside the ribosome and directly helps in the translation of mRNA into proteins.

11. Simplest amino acid

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

12. An anticodon is found at

1. mRNA
2. rRNA
3. DNA
4. tRNA

Feedback: An anticodon is found at one end of a transfer RNA (tRNA) molecule. During protein synthesis, each time an amino acid is added to the growing protein, a tRNA forms base pairs with its complementary sequence on the mRNA molecule, ensuring that the appropriate amino acid is inserted into the protein.

13. Which is a reducing sugar?

1. Gluconic acid
2. Galactose
3. Sucrose
4. Both A and B

14. A high content of triglycerides are found in

1. VLDL
2. HDL
3. LDL
4. Chylomicrons

Feedback: LDL contains high content of Triglycerides.

15.Which of the following is a phospholipid?

1. Sterol
2. Cholesterol
3. Lecithin
4. Steroid