Biomolecules and Enzymes

Selenium is an important constituent of the enzyme glutathione peroxidase, which is responsible for destroying lipid-damaging peroxides.

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.

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

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.

H2A is important for packaging DNA into chromatin. Since, H2A packages DNA molecules into chromatin, the packaging process will effect gene expression. H2A has been correlated with DNA modification and epigenetics. H2A plays a major role in determining the overall structure of chromatin.

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

Thymidylate synthase utilises tetrahydrofolate as a prosthetic group.

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.

Glycin is an achiral amino acid. Glycin is the simplest, naturally occurring amino acid, which is a constituent of most proteins.

Rice is deficient in Lysine. It is a basic amino acid, which is a constituent of most  of the proteins. It is an essential nutrient in the diet of vertebrates.

Antibodies are proteins. Proteins are any of a class of nitrogenous organic compounds which have large molecules composed of one or more long chains of amino acids and are an essential part of all living organisms, especially as structural components of body tissues such as muscle, hair etc. and as enzymes and antibodies.