Question 1

Identify the correct statements about biomolecules. A. Lipids are generally water soluble. B. Proteins are polypeptides. C. Polysaccharides are long chains of sugars. D. Adenine and guanine are substi

Accepted Answer

Statement A is incorrect because lipids are generally water insoluble. Statement B is correct because proteins are polypeptides, which are linear chains of amino acids linked by peptide bonds. Statement C is correct because polysaccharides are long chains of sugars (monosaccharides). Statement D is incorrect because adenine and guanine are substituted purines, whereas cytosine, uracil, and thymine are substituted pyrimidines. Statement E is correct because almost all enzymes are proteins, with a

Question 2

The amino acid that gives a red-blood colour on treating its sodium fusion extract with sodium nitroprusside is

Accepted Answer

Methionine is the only amino acid among the given options that contains sulphur. During sodium fusion, an organic compound containing both nitrogen and sulphur forms sodium thiocyanate (NaSCN). This extract gives a blood-red colour when treated with Fe^ 3+ ions due to the formation of ferric thiocyanate, [Fe(SCN)]^ 2+ . Although the question mentions sodium nitroprusside (which typically yields a violet colour with sulphide ions), the blood-red colour specifically confirms the presence of both n

Question 3

The correct statement with regard to the secondary structure of DNA/RNA is :

Accepted Answer

DNA possesses a double strand helix structure and contains adenine, guanine, cytosine, and thymine as its four bases. RNA possesses a single strand helix structure and contains adenine, guanine, cytosine, and uracil as its four bases. Thus, the statement that DNA possesses a double strand helix structure and contains thymine as one of the four bases is correct. Answer: DNA possesses a double strand helix structure and contains thymine as one of the four bases.

Question 4

Which of the following statements are correct regarding amino acids ? A. They are substituted methanes. B. Serine is an aromatic amino acid. C. Valine is a neutral amino acid. D. Lysine is an acidic a

Accepted Answer

Amino acids are organic compounds containing an amino group and an acidic group as substituents on the same carbon, i.e., the -carbon. Therefore, they are considered substituted methanes. Statement A is correct. Serine contains a hydroxymethyl group ( -CH _2 OH ) as its side chain and is an aliphatic amino acid, not an aromatic one. Aromatic amino acids include phenylalanine, tyrosine, and tryptophan. Statement B is incorrect. Valine contains one amino group and one carboxyl group, making it a n

Question 5

Match the vitamins in List I with their sources in List II List I List II A. vitamin A I. meat B. vitamin B_ 12 II. sunflower oil C. vitamin E III. green leafy vegetables D. vitamin K IV. carrots Choo

Accepted Answer

Vitamin A is primarily found in sources like carrots, fish liver oil, butter, and milk. Vitamin B_ 12 is found in animal products such as meat, fish, egg, and curd. Vitamin E is abundant in vegetable oils like sunflower oil and wheat germ oil. Vitamin K is predominantly found in green leafy vegetables. Therefore, the correct matching is A-IV, B-I, C-II, D-III.

Question 6

The correct statement about peptides and proteins is

Accepted Answer

In -helix structure, the polypeptide chain is twisted into a right-handed screw, not left-handed. Tertiary structure represents the overall folding of a single polypeptide chain. Proteins with two or more polypeptide subunits exhibit quaternary structure. Proteins can be biologically active in their tertiary structure as well, so it is incorrect to say only proteins with quaternary structure are active. In -pleated sheet structures, all peptide chains are stretched out to nearly maximum extensio

Question 7

Alpha-helix is found in which level of protein structure ?

Accepted Answer

The primary structure of a protein refers to the linear sequence of amino acids. The secondary structure refers to the local folded structures that form within a polypeptide due to interactions between atoms of the backbone. The most common types of secondary structures are the -helix and the -pleated sheet. The tertiary structure is the overall three-dimensional structure of a polypeptide. The quaternary structure is the arrangement of multiple folded protein or coiling protein molecules in a m

Question 8

The following reaction depicts the activity of a particular class of enzymes : Identify the enzyme class 'E' from the following options :

Accepted Answer

The given reaction shows the removal of groups X and Y from the substrate, resulting in the formation of a double bond (C=C) between the carbon atoms. Enzymes that catalyze the removal of groups from substrates by mechanisms other than hydrolysis, leaving double bonds, are classified as lyases. Therefore, the enzyme class 'E' is Lyases. Answer: Lyases

Question 9

Match List I with List II : List I List II A. Trypsin I. Intercellular ground substance B. Morphine II. Lectin C. Concanavalin A III. Enzyme D. Collagen IV. Alkaloid Choose the correct answer from the

Accepted Answer

Trypsin is a proteolytic enzyme that helps in the digestion of proteins. Morphine is a secondary metabolite which belongs to the category of alkaloids. Concanavalin A is a secondary metabolite classified as a lectin. Collagen is a structural protein that acts as an intercellular ground substance in animal tissues. Therefore, the correct matching is A-III, B-IV, C-II, D-I. Answer: A-III, B-IV, C-II, D-I

Question 10

Which one of the following enzymes contains 'Haem' as the prosthetic group?

Accepted Answer

In peroxidase and catalase, which catalyze the breakdown of hydrogen peroxide to water and oxygen, haem is the prosthetic group and it is part of the active site of the enzymes. Zinc is the cofactor in enzyme carbonic anhydrase. RuBisCo is the most abundant protein in whole of the biosphere. Succinate is the substrate of enzyme succinic dehydrogenase.

Question 11

Match List I with List II: array |l|l|l|l| & List - I & & List - II \ A . & Adenosine & (i) & Nitrogen base \ B. & Adenylic acid & (ii) & Nucleotide \ C. & Adenine & (iii) & Nucleoside \ D. & Alan

Accepted Answer

The correct answer is A-III, B-II, C-I, D-IV - Adenosine - It is a nucleoside which is composed of nitrogen base and sugar only. - Adenylic acid - It is a nucleotide which is composed of nitrogen base, sugar and a phosphate group is esterified to the sugar. - Adenine - Nitrogen base (Purine) Alanine - An amino acid that contains a methyl group as the ' R ' group.

Question 12

The protein portion of an enzyme is called:

Accepted Answer

There are number of cases in which non-protein constituents called co-factors are bound to the enzyme to make the enzyme catalytically active. In these instances, the protein portion of the enzymes is called the apoenzyme. Three kinds of co-factors are identified prosthetic groups, co-enzymes and metal ions. Prosthetic groups are organic compounds and they are tightly bound with apoenzyme. Co-enzymes are also organic compounds but their association with apoenzyme is only transient.

Question 13

Why can't insulin be given orally to diabetic patients?

Accepted Answer

Insulin can't be administered orally to diabetic patients as being the proteinaceous molecule, it will be digested in gastro-intestinal tract.

Question 14

Match List - I with List - II array llll & array l List-I \ (Name of the array & & array l List-II \ (Deficiency array \ & Vitamin) & & array l disease) array \ A. & Vitamin B_ 12 & I. & Cheilosis

Accepted Answer

Correct match A. Vitamin B 12 IV. Pernicious Anaemia B. Vitamin D III. Rickets C. Vitamin B _2 I. Cheilosis D. Vitamin B6 II. Convulsions

Question 15

Sugar 'X' A. is found in honey. B. is a keto sugar. C. exists in and - anomeric forms. D. is laevorotatory. ' X ' is :

Accepted Answer

D-fructose is a keto sugar exists in and anomeric forms. Its is laevorotatory, found in honey.

Question 16

Name the class of enzyme that usually catalyze the following reaction : S - G + S ^ \# ~S + S ^ \# - G Where, G a group other than hydrogen S a substrate S ^ \# another substrate

Accepted Answer

Enzymes catalysing a transfer of G group, (other than hydrogen) between a pair of substrates, S and S ^ are known as transferases. S - G + S ^ \# ~S + S ^ \# - G - Ligases catalyse the linking together of 2 compounds such as C-O, C-S, C-N bonds etc - Lyases catalyse removal of groups from substrates by mechanisms other than hydrolysis leaving double bonds Hydrolases are enzymes that catalyse hydrolysis of ester, ether, peptide, glycosidic, C - C , C - halide or P - N bonds.

Question 17

Given below are two statements : Statement I: Glycogen is similar to amylose in its structure. Statement II : Glycogen is| found in yeast and fungi also. In the light of the above statements, choose t

Accepted Answer

Glycogen is similar to amylopectin in its structure. Glycogen is also found in yeast and fungi. So statement I is false but statement II is true.

Question 18

The reagents with which glucose does not react to give the corresponding tests/products are A. Tollen's reagent B. Schiff's reagent C. HCN D. NH _2 OH E. NaHSO _3 Choose the correct options from the g

Accepted Answer

Despite having the aldehyde group glucose does not give Schiff's test and it does not form the hydrogen sulphite addition product with NaHSO _3.

Biomolecules — Previous Year Questions & Solutions