Biomolecules and Enzymes

This option is correct because Mg is present in chlorophyll and helps in photosynthesis, is helpful in activation of enzymes and also an Information carrier.

This option is correct because galactose oxidase is a monomeric enzyme that contains a single copper ion and catalyses the stereospecific oxidation of primary alcohols to their corresponding aldehydes.

This option is correct because urease is a nickel-containing metalloenzyme of high molecular weight that catalyses the hydrolysis of urea into carbon dioxide and ammonia and dopamine β-hydroxylase is a copper-containing enzyme that synthesises norepinephrine from dopamine.

Ureoplasma does not secrete DNAase. Hydrogen peroxide and ammonia are excreted as virulence factor.

This is the correct match. Tetanus toxin acts on the central nervous system to prevent the release of inhibitory factor. In botulism, the toxin binds to the axon near the neuromuscular junction and prevents the secretion of acetylcholine. Cholera toxin hampers the activity of the enzyme adenylate cyclase in the cell. Diphtheria toxin inactivates elongation factor 2.

According to cross-linkage theory, ageing is caused due to increase in number of bonds between proteins and nucleic acid molecules.

Interferons are small glycoprotein substances made and released by host cells in response to the presence of several pathogens, such as viruses, bacteria, parasites and also tumor cells. They are produced by RDT (Recombinant DNA Technology).

Arginine is an α-amino acid. At the level of molecular genetics, in the structure of the messenger ribonucleic acid mRNA, CGU, CGC, CGA, CGG, AGA, and AGG, are the triplets of nucleotide bases or codons that code for arginine during protein synthesis. In mammals, arginine is classified as a semiessential or conditionally essential amino acid, depending on the developmental stage and health status of the individual.

Ribonuclease A is made up of a single polypeptide chain of 124 residues.

Thymidylate synthase utilises tetrahydrofolate as a prosthetic group.

Correct answer. NAD⁺ is synthesised through two metabolic pathways. It is produced either in a de novo pathway from amino acids or in salvage pathway by recycling preformed components.

Correct answer. Ribonuclease A (RNase A) is a small (124 amino acids) digestive enzyme secreted by the pancreas and is an endonuclease specifically designed to hydrolyse RNA phosphodiester bonds which covalently link ribonucleotides particularly those linked to pyrimidine bases such as uracil. It can be inhibited by ribonuclease inhibitor protein, by heavy metal ions (like Pb²⁺, Hg⁺  etc.), and by uridine-vanadate complexes.

Initiation of polypeptide chain is always brought about by an amino acid called methionine.

Proteins are biopolymers composed of amino acid monomers linked by peptide bonds (amide bonds between -NH2 and -COOH groups). The peptide bond formation creates polypeptide chains, which fold into functional three-dimensional protein structures. All other options describe incorrect polymer types.

Hydrogen bond is a weak bond between two molecules resulting from an electrostatic attraction between a proton in one molecule and an electronegative atom in the other.