Biomolecules and Enzymes

The trace mineral sulfur is one of the major components in the biochemical structure of the amino acids cysteine, methionine, taurine and glutathione. The synthesis of many types of proteins in the body require sulfur to be present, these including proteins that are found primarily in the hair, the muscle tissues and the skin - these fibrous proteins are made from sulfur rich amino acids.

The tertiary structure of a protein is a description of the way the whole chain (including the secondary structures) folds itself into its final 3-dimensional shape. This is often simplified into models like the following one for the enzyme dihydrofolate reductase. Enzymes are, of course, based on proteins.The tertiary structure of a protein is held together by interactions between the the side chains - the R groups. There are several ways this can happen such as ionic interactions,Sulphur bridges,hydrogen bonding.A disulfide bond (SS-bond), also called a disulfide bridge, is a strong covalent bond between two sulfhydryl groups. This bond is very important to the folding, structure, and function of proteins. The presence of S-S then helps to maintain the tertiary structure of the protein. An amino acid that commonly forms S-S bonds in proteins in cysteine.

Proteins are not responsible composition of sex hormones.Two or three fatty acids are usually polymerized with glycerol, but other lipids, such as steroids, which do not form polymers. Steroids function both as hormones such as the sex hormones estrogen and testosterone and as structural material such as cholesterol, an integral part of animal cell membranes.

If an a-carbon atom has four different groups attached to it. Then it is asymmetric and it exhibits optical isomerism. Except glycine all amino acids exhibit optical activity.

Cysteine, a nonessential amino acid, is one of the 20 building blocks of protein. Cysteine is a part of organic molecules containing an amino group, which can combine in linear arrays to form proteins in living organisms. Cysteine can be synthesized by the body and is not essential to the diet. Its key chemical feature is a thiol group that contains sulfur.

Lysine helps the body absorb calcium and decreases the amount of calcium that is lost in urine. Because calcium is crucial for bone health, so lysine helps to prevent bone loss associated with osteoporosis.lysine in combination with L-arginine makes bone-building cells more active and enhances production of collagen.

Denaturation is a process by which the native form of protein structure is disorganized. This causes drastic changes in a protein molecule. Denaturation is caused by some physical and chemical agents. Denaturation causes loss in biological activity of protein. The peptide bonds in the primary structure are not hydrolyzed, but helical structure of the protein is lost. Protein is soluble in water but after denaturation it is insoluble and easily digested.Denaturation is usually a irreversible process, but it is sometimes reversible. The coagulation of egg white on boiling of egg protein is an example of irreversible protein denaturation.

Non competitive inhibitor

Prosthetic group

Nucleic acids

Histones

A hapten is a small molecule that can elicit an immune response only when attached to a large carrier such as a protein; the carrier may be one that also does not elicit an immune response by itself.

IgM

Alpha-keratin is a structural protein found in vertebrates. It is the primary component of hair, wool, nails, and the outer layer of skin.

 The correct option is 4.