Given below is the diagrammatic representation of one of the categories of small molecular weight organic compounds in the living tissues. Identify the category shown and the one blank component “X” in it.

Category Component

(a)Cholesterol Guanine
Category Component

(b)Amino acid NH₂
Category Component

(c)Nucleotide Adenine
Category Component

(d)Nucleoside Uracil

Solution

A combination of a nitrogen base with a pentose sugar is known as nucleoside. The nitrogen base combines with the sugar molecule at its carbon atom 1'in aglycosidic bond (C – N – C) by one of its nitrogen atoms(usually 1 in pyrimidines and 9in purines).Depending upon the type of pentose sugar, nucleosides are differentiated into ribonucleosides and deoxyribonucleosides.

The curve given below shows enzymaticactivity with relation to three conditions (pH,temperature and substrate concentration.) What do the two axis (x and y) represent ?

x - axis y-axis

(a)enzymatic activity pH
x - axis y-axis

(b)temperature enzyme activity
x - axis y-axis

(c)substrate concentration enzymatic activity
x - axis y-axis

(d)enzymatic activity temperature

Solution

In the given curve the temperature and enzyme activity relation is shown.

Which one of the following structural formulae of two organic compounds is correctly identified along with its related function ?

B : Adenine — a nucleotide that makes up nucleic acids
A: Triglyceride — major source of energy
B : Uracil — a component of DNA
A: Lecithin — a component of cell membrane

Solution

Lecithin is a fat like substance called a phospholipid,which is a part of plasma membrane.

Carrier ions like Na+facilitate the absorption of substances like:

amino acids and glucose
glucose and fatty acids
fatty acids and glycerol
fructose and some amino acids

Solution

Massive ions like Na+facilitate the absorption of substances like amino acid and glucose through co-transport.

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

sulphur and magnesium
magnesium and sodium
calcium and phosphorus
phosphorus and sulphur

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

Holoenzyme
Apoenzyme
Isoenzyme
Coenzyme

Solution

Coenzyme is an organic substance that enhances the action of an enzyme by binding with the protein molecule.

Carbohydrates, the most abundant bio-molecules on earth,are produced by :

some bacteria, algae and green plant cells
fungi, algae and green plant cells
all bacteria, fungi and algae
viruses, fungi and bacteria

Solution

Some bacteria (such as Rhodopseudomonas), algae and green plant cells produce carbohydrates

Which one of the following hydrolyses internal phosphodiester bonds in a polynucleotide chain?

Lipase
Protease
Endonuclease
Exonuclease

Solution

Endonucleases hydrolyse internal phosphodiester bonds in a polynucleotide chain (i.e.,DNA). While exonucleases hydrolyse terminal phosphodiester bonds in a polynucleotide chain (i.e.,DNA).

Which of the following is the simplest amino acid?

Alanine
Asparagine
Glycine
Tyrosine

Solution

The general structure of an amino acid is

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

formation of the product
pH optimum value
K_m value
molecular size of the enzyme

Solution

K_m(Michealis Menten constant) is defined as that substrate concentration at which under optimum conditions the rate of an enzyme catalysed reaction reaches half the maximum rate. K_mis inversely proportional to affinity of enzyme for its substrate.

UnAttempted

0

Attempted

0

Correct

0

Wrong

0

Complete

Category	Component
(a)Cholesterol	Guanine

Category	Component
(b)Amino acid	NH₂

Category	Component
(c)Nucleotide	Adenine

Category	Component
(d)Nucleoside	Uracil