Question

Which one of the following statements about cytochrome ${{P}_{450}}$ is wrong?
(a) It contains iron
(b) It is a coloured cell
(c) It has an important role in metabolism
(d) It is an enzyme involved in oxidation reactions

Answer 1

Animals, plants, fungi, protists, bacteria, and archaea, as well as viruses, have all been shown to have CYP enzymes. They are not, however, ubiquitous; for example, they have not been discovered in Escherichia coli.

Complete answer:
Cytochromes ${{P}_{450}}$ (CYPs) are a monooxygenase superfamily of enzymes that include heme as a cofactor. These proteins oxidise steroids, fatty acids, and xenobiotics in mammals, and are crucial for chemical clearance as well as hormone production and breakdown. These proteins have a role in the production of defence chemicals, fatty acids, and hormones in plants. In electron transfer chains, CYPs are the terminal oxidase enzymes, which are classified as ${{P}_{450}}$ -containing systems.
Cytochrome refers to a category of proteins that include a heme metallic prosthetic group. Cytochrome ${{P}_{450}}$ is a monooxygenase that hydroxylates its substrates using one oxygen atom from ${{O}_{2}}$ and produces water with the other. It has a significant impact on medication metabolism.
Cytochrome is a respiratory pigment-mixture of iron and protein that serves as electron acceptors, rather than a coloured cell. Cytochromes are membrane-bound heme proteins that contain heme groups and are largely responsible for electron transport to generate ATP.
Hence option B is correct.

Note:
When the enzyme is in the reduced state and complexed with carbon monoxide, the spectrophotometric peak at the wavelength of the absorption maximum of the enzyme (450 nm) is called " ${{P}_{450}}$ ." To decrease the iron, most CYPs require a protein partner to donate one or more electrons (and eventually molecular oxygen).