Question 1

Which of the following carbohydrates is not a monosaccharide?

Accepted Answer

Sugars are categorized into monosaccharides or disaccharides.Monosaccharides are made up of one single unit of sugar and thus cannot be hydrolyzed further into simpler compounds. Examples:- galactose, glucose, and fructose.These are the building blocks of other carbohydrates like disaccharides and polysaccharides.Disaccharides are made up of two monosaccharides linked by glycosidic linkage and will be again broken back down into the latter during digestion Sucrose is the scientific name for table sugar and is a disaccharide.So the correct answer is option D.

Question 2

A carbohydrate molecule consumes 2 molecules of  HIO_4 . The number of carbon-carbon bonds broken by this acid is:

Accepted Answer

One molecule of  HIO_{4}  breaks one carbon - carbon double bond.Thus, two molecules of  HIO_{4}  will break two carbon - carbon double bonds.

Question 3

A tetrapeptide has  -COOH  group on alanine. This produces glycine (Gly), valine (Val), phenyl alanine (Phe) and alanine (Ala), on complete hydrolysis. For this tetrapeptide, the number of possible sequences (primary structures) with   NH_{2}  group attached to a chiral centre is:

Accepted Answer

Since  -COOH  group is attached to alanine, one terminal of the tetrapeptide contains alanine. Thus, its position is fixed.Glycine is achiral whereas valine and phenylalanine are chiral. Thus,  -NH_2  group is attached to either valine or phenylalanine.Thus following are the four possible combinations of the tetrapeptide. H_2N-Val-Gly-Phe-Ala-COOH H_2N-Val-Phe-Gly-Ala-COOH H_2N-Phe-Gly-Val-Ala-COOH H_2N-Phe-Val-Gly-Ala-COOH Therefore, the correct option is A.

Question 4

The two functional groups present in a typical carbohydrate are:

Accepted Answer

Carbohydrates are primarily hydroxyl carbonyl compounds. Hence,   C = O  and  OH  bonds are present.

Question 5

The presence or absence of hydroxyl group on which carbon atom of sugar differentiates RNA and DNA?

Accepted Answer

The sugar present in DNA is called deoxyribose, the sugar present in RNA is called simply ribose.Ribose has a hydroxyl group attached at the 2nd C-atom while deoxyribose does not.

Question 6

Biuret test is not given by:

Accepted Answer

Biuret test is given by an amide linkage. It is present in urea, polypeptides and proteins (polypeptides). Carbohydrates do not have any amide linkages.Option A is correct.

Question 7

Question 8

The prosthetic group of haemoglobin is:

Accepted Answer

The Heme group in hemoglobin is a prosthetic group located in the porphyrin, which is a tetramer of cyclic carbon groups. It contains an organic component called a protoporphyrin made up of four pyrrole rings and an iron atom in the ferrous state ( Fe^{2+} ).Option C is correct.

Question 9

Starch is a mixture of two components, a water soluble component amylose(15-20%) and a water insoluble component amylopectin (80-85%). The aqueous solution of amylose gives a blue colour with iodine solution due to the formation of:

Accepted Answer

Inclusion complex is a host-guest addition compound.The space available within the crystal lattice of the host molecule, i.e., amylose is in the form of tunnels and the size of the tunnels is such that it can easily accommodate guest molecules, i.e., iodine molecules to form an addition compound called the inclusion complex.The blue colour, however, disappears on heating and reappears on cooling.Option C is correct.

Question 10

Insulin production and its action in human body are responsible for the level of diabetes. This compound belongs to which of the following categories?

Accepted Answer

A chemical substance produced in the body that controls and regulates the activity of certain cells or organs is called hormone. Insulin is a hormone secreted by the pancreas and controls the metabolism of glucose and maintains glucose level in the blood.

Biomolecules