Biology Multiple Choice Questions on “Biomacromolecules – 1”.
1. What is the unit of measurement of weight of biomacromolecules?
a) Nanometer
b) Farad
c) Angstrom
d) Dalton
Answer: d
Clarification: The molecular weight of biomacromolecules such as nucleic acids, proteins and carbohydrates is measured in Daltons. Angstrom and nanometer are units of length while farad is a unit of capacitance.
2. What is the approximate weight of compounds found in acid soluble pool of grinded tissue?
a) 1,000 – 10,000 Da
b) 2 – 30 Da
c) 18 – 800 Da
d) 6,000 – 50,000 Da
Answer: c
Clarification: When tissue is grinded in trichloroacetic acid and strained, it separates into an acid soluble pool and an acid insoluble pool. The acid soluble pool contains compounds whose approximate molecular weight is between 18 to 800 Da.
3. Which of these compounds is not present in the acid insoluble fraction of homogenized tissue?
a) Proteins
b) Fats
c) Vitamins
d) Nucleic acids
Answer: c
Clarification: The acid insoluble pool or fraction of the homogenized plant or animal tissue contains proteins, lipids, carbohydrates and nucleic acids. These molecules are also known as biomolecules. Vitamins are not present.
4. Which of these compounds do not have a molecular weight greater than 10,000 Da?
a) Lipids
b) Proteins
c) Polysaccharides
d) Nucleic acids
Answer: a
Clarification: The acid insoluble layer of homogenized, strained tissue consists of proteins, nucleic acids, lipids and polysaccharides. Out of these biomacromolecules, lipids have a molecular weight lesser than 10,000 Da.
5. Micro-molecules of the tissue are also known as ______
a) bio compounds
b) biomolecules
c) biomacromolecules
d) nanoparticles
Answer: b
Clarification: Micro-molecules are those molecules that have a molecular weight less than 1000 Da or from 1 to 1000 Da. They are also known as biomolecules. They contain vitamins and minerals that are required by the body.
6. What is the maximum weight of biomolecules?
a) 800 Da
b) 10,000 Da
c) 1000 Da
d) 5000 Da
Answer: c
Clarification: Biomolecules or micro-molecules have an approximate molecular weight between 1 to 1000 Da. Thus, 1000 Da is the maximum weight. Biomacromolecules have a molecular weight greater than 10,000 Da.
7. Which of these substances is not polymeric?
a) Lipids
b) Nucleic acids
c) Proteins
d) Polysaccharides
Answer: a
Clarification: When tissue matter is homogenized and strained, it separates into an acid soluble pool and an acid insoluble pool. The acid insoluble pool contains proteins, nucleic acids, polysaccharides and lipids. Out of these, only lipids are not polymeric.
8. The molecular weight of lipids does not exceed _____
a) 5000 Da
b) 1000 Da
c) 10,000 Da
d) 800 Da
Answer: d
Clarification: Proteins, nucleic acids and polysaccharides are polymeric substances and are biomacromolecules whose approximate molecular weight is greater than 10,000 Da. Lipids are not polymeric and the weight does not exceed 800 Da.
9. When tissue is homogenized, the disrupted cell membrane separates in the form of _____
a) solid aggregates
b) lipoprotein complexes
c) vesicles
d) lipopolysaccharides
Answer: c
Clarification: The cell membrane is predominantly composed of lipids, which form a bilayer around the cytosol and the cell organelles. When the cell is disrupted, the lipid bilayer separates and forms vesicles.
10. Lipids are not macromolecules as their weight does not exceed 800 Da. True or false?
a) True
b) False
Answer: b
Clarification: Unlike macromolecules such as proteins, polysaccharides and nucleic acids which have a molecular weight greater than 10,000 Da, the weight of lipids does not exceed 800 Da. However, lipids are not polymers but are considered macromolecules.
11. What percentage of the total cellular mass is water?
a) 5 – 7
b) 50 – 60
c) 10 – 15
d) 70 – 90
Answer: d
Clarification: Water is the main component of the cytosol. Hence, the cell contains 70% to 90% water. Various ions, molecules and compounds required for the functioning of the cell are dissolved in the water.
12. What percentage of the total cellular mass is nucleic acids?
a) 1 – 2
b) 50 – 60
c) 5 – 7
d) 20 – 30
Answer: c
Clarification: Nucleic acids such as deoxyribonucleic acid (DNA) and ribonucleic acid (RNA) make up the genetic material of the cell. DNA is present inside the nucleus while RNA is present both in the nucleus and cytoplasm. It makes up 5 – 7% of the total cellular mass.
13. 10 – 15% of the total cellular mass is ______
a) nucleic acids
b) water
c) proteins
d) carbohydrates
Answer: c
Clarification: 10 – 15% of the total cellular mass is taken up by proteins. Proteins are synthesized in the cytosol by the information present in the nucleic acids. Nucleic acids are the genetic material of the cell.
14. What percentage of the total cellular mass is carbohydrates?
a) 3
b) 2
c) 1
d) 10
Answer: a
Clarification: 3% of the total cellular mass is taken up by carbohydrates. 2% is taken up by lipids, 1% is taken up by various ions and 10% of the total cellular mass is taken up by the various proteins present in the cell.
15. 2% of the total cellular mass is _____
a) proteins
b) lipids
c) ions
d) nucleic acids
Answer: b
Clarification: 2% of the total cellular mass is taken up by lipids. In the cell, lipids are predominantly found in the cell membrane and nuclear membrane, where they are present in the form of a phospholipid bilayer.