Question

Detoxification of lipid soluble drugs and other harmful compounds in ER is carried out by
A) Cytochrome $a_1$–$a_3$
B) Cytochrome c
C) Cytochrome $b_f$
D) Cytochrome $P_450$

Answer 1

Detoxification is the process in which toxins are converted into less harmful chemicals by oxidation, reduction and hydrolysis reaction. A group of enzymes mediated in the reactions. In these reactions chemicals convert. The converted chemicals are then attached to another substance via a conjugation reaction.

Complete Answer:
$P_450$ are a group of oxygenase enzymes which are present on ER of liver cells are responsible for detoxification of a number of xenobiotics, toxin products ,and drugs of endogenous metabolism inside our body. The detoxification process is done by the smooth endoplasmic reticulum in liver cells . Liver cells contain enzymes that catalyze a number of reactions and can make lipid-soluble drugs and metabolic wastes which are soluble in water, so that these can easily be excrete out from the body .

Additional information:
Functions of endoplasmic reticulum:-
->Smooth endoplasmic reticulum is the site of protein synthesis
->It helps in transportation of intracellular and intercellular transport of materials. It transports chemicals between cells and within cells.
->SER also helps in protein synthesis.
->SER detoxifies many drugs and poisons in liver cells.
->Proteins and lipids synthesized on ER are used for making cell membranes. The process is known as membrane biogenesis.
->It provides a large surface area for various metabolic reactions.

Hence the correct answer is option ‘D’.

Note: The cytochrome $P_450$ are a group of heme-containing isoenzymes. These enzymes primarily involved in the lipid bilayer of the endoplasmic reticulum of hepatocytes, it takes part in the metabolism of many drugs, steroids and carcinogens.