Biomolecules and Enzymes

Chromoproteins are proteins, such as hemoglobin or rhodopsin. They contain a pigmented nonprotein group, as heme, riboflavin, or retinal.

All the above consists of diaminopimelic acid in their cell wall.

Arginine is the substrate for the enzyme nitric oxide synthase, which converts it into nitric oxide and citrulline in biological systems.

Myosin is a motor protein that exhibits properties of both fibrous proteins (due to its long tail) and globular proteins (due to its motor head domain).

Albumins, specifically serum albumin, are the most abundant proteins found in human blood plasma.

Loop regions are flexible, unstructured segments of a polypeptide chain that connect secondary structural elements like alpha-helices and beta-strands.

Methionine is a key amino acid in methyl group metabolism, as it is converted to S-adenosylmethionine (SAM), the primary methyl donor in the cell.

Proteins are heteropolymers because they are composed of a sequence of different amino acids linked together, rather than repeating units of the same monomer.

Proline has a unique cyclic structure where the side chain is bonded to the nitrogen atom of the backbone, which restricts rotation and introduces a kink in the polypeptide chain.

Glycine is the simplest amino acid because its side chain is just a single hydrogen atom, making it the only achiral amino acid.

The polypeptide backbone consists of the repeating N-Calpha-C sequence. The side chains (R-groups) are attached to the alpha-carbon but are not considered part of the backbone itself.

In biological systems, proteins are synthesized using only L-amino acids, which are the L-stereoisomers.

A prosthetic group is a non-protein organic molecule or metal ion that is tightly or covalently bound to an enzyme and is essential for its catalytic activity.

Apoferritin is the protein shell of ferritin that does not contain the iron core. Ferritin, transferrin, and haemoglobin all contain iron.