Chapter 9: Biomolecules

It is said that the elemental composition of living organisms and that of

inanimate objects (like earth’s crust) are similar in the sense that all the

major elements are present in both. Then what would be the difference

between these two groups? Choose the correct answer from among the

following:

a. Living organisms have more gold in them than inanimate objects

b. Living organisms have more water in their body than inanimate

objects

c. Living organisms have more carbon, oxygen and hydrogen per

unit mass than inanimate objects.

d. Living organisms have more calcium in them than inanimate

objects.

Many elements are found in living organisms either free or the form of

compounds. Which of the following is not found in living organisms?

a. Silicon

b. Magnesium

c. Iron

d. SodiumSolution:

Option (a) is the answer.

Aminoacids have both an amino group and a carboxyl group in their

structure. Which one of the following is an amino acid?

a. Formic acid

b. Glycerol

c. Glycolic Acid

d. Glycine

An amino acid under certain conditions has both positive and negative

charges simultaneously in the same molecule. Such a form of amino acid

is called

a. Acidic form

b. Basic form

c. Aromatic form

d. Zwitterionic form

Sugars are technically called carbohydrates, referring to the fact that

their formulae are only multiple of C(H2O). Hexoses, therefore, have six

carbons, twelve hydrogens and six oxygen atoms. Glucose is a hexose.

Choose from among the following another hexose.

a. Fructose

b. Erythrose

c. Ribulose

d. Ribose

When you take cells or tissue pieces and grind them with an acid in a

mortar and pestle, all the small biomolecules dissolve in the acid.

Proteins, polysaccharides and nucleic acids are insoluble in mineral acid

and get precipitated. The acid-soluble compounds include amino acids,

nucleosides, small sugars etc. When one adds a phosphate group to a

nucleoside, one gets another acid-soluble biomolecule called

a. Nitrogen base

b. Adenine

c. Sugar phosphate

d. Nucleotide

When we homogenise any tissue in acid the acid-soluble pool

represents

a. Cytoplasm

b. Cell membrane

c. Nucleus

d. Mitochondria

The most abundant component of living organisms is

a. Protein

b. Water

c. Sugar

d. Nucleic acid

A homopolymer has only one type of building block called monomer

repeated ‘n’ number of times. A heteropolymer has more than one type

of monomer. Proteins are heteropolymers usually made ofa. 20 types of monomers

b. 40 types of monomers

c. 30 types of monomers

d. only one type of monomer

Proteins perform many physiological functions. For example, some

functions as enzymes. Which of the following represents an additional

function that some proteins discharge?

a. Antibiotics

b. Pigment conferring colour to skin

c. Pigments making colours of flowers

d. Hormones