Table of Contents
Which of the following is phase II metabolic?
Phase II metabolic reactions are characterized as conjugation reactions and are catalyzed by enzymes known as transferases.
What is a phase 2 enzyme?
Phase 2 enzymes traditionally refer to the enzymes catalyzing the conjugation reactions, such as glutathione S-transferase (GST), UDP-glucuronosyltransferase ( UGT), N-acetyltransferase (NAT), and sulfotransferase (SULT).
Where does phase II metabolism occur?
Glucuronidation, the most common phase II reaction, is the only one that occurs in the liver microsomal enzyme system. Glucuronides are secreted in bile and eliminated in urine. Thus, conjugation makes most drugs more soluble and easily excreted by the kidneys.
What is the phase I and phase II reaction explain in detail?
Phase I reactions of drug metabolism involve oxidation, reduction, or hydrolysis of the parent drug, resulting in its conversion to a more polar molecule. Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine.
What are the 2 phases in the process of metabolism?
Metabolism is often divided into two phases of biochemical reaction – phase 1 and phase 2. Some drugs may undergo just phase 1 or just phase 2 metabolism, but more often, the drug will undergo phase 1 and then phase 2 sequentially.
Which enzyme is important in the phase II reactions?
Phase II drug metabolising enzymes are mainly transferases. This review covers the major phase II enzymes: UDP-glucuronosyltransferases, sulfotransferases, N-acetyltransferases, glutathione S-transferases and methyltransferases (mainly thiopurine S-methyl transferase and catechol O-methyl transferase).
What is the role of Phase II enzymes in metabolism?
Phase II of metabolism may or may not be preceded by Phase I reactions. Phase II enzymes undoubtedly play an important role in the detoxification of various xenobiotics.
What is Phase 1 and Phase 2 biotransformation?
Phase I and Phase II Biotransformation. Reactions catalyzed by xenobiotic biotransforming enzymes are generally divided into two groups: Phase I and phase II. 1. Phase I reactions involve hydrolysis, reduction and oxidation, exposing or introducing a functional group (-OH, -NH. 2, -SH or –COOH) to slightly increase hydrophilicity.
What are Phase II drug detoxifying pathways?
** Thus, phase II Rx.s can be regarded as truly detoxifing pathways in drug metabolism,w- a few exceptions. Phase II feature Conjugating grp.(glucuronic acid,sulfate,methyl & acetyl) is activated in form of a coenzyme and involves a
What are the steps involved in Phase 1 reactions?
Phase I reactions involve hydrolysis, reduction and oxidation, exposing or introducing a functional group (-OH, -NH 2, -SH or –COOH) to slightly increase hydrophilicity. 2.