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.
What are the 2 phases in the process of metabolism quizlet?
Metabolism has two phases. ANABOLISM: Constructive metabolism.
Where does Phase 1 and 2 metabolism occur?
The liver is the primary site for metabolism. Liver contains the necessary enzymes for metabolism of drugs and other xenobiotics. These enzymes induce two metabolism pathways: Phase I (functionalization reactions) and Phase II (biosynthetic reactions) metabolism.
What are metabolic phases?
The metabolism of xenobiotics is often divided into three phases:- modification, conjugation, and excretion. These reactions act in concert to detoxify xenobiotics and remove them from cells.
What is the purpose of phase 2 metabolism?
The ultimate goal of phase II reactions is to form water-soluble products that can be excreted by the body. A drug can ultimately undergo further metabolism during Phase III.
What is phase II metabolism?
Phase II reactions involve conjugation by coupling the drug or its metabolites to another molecule, such as glucuronidation, acylation, sulfate, or glicine. The substances that result from metabolism may be inactive, or they may be similar to or different from the original drug in therapeutic activity or toxicity.
Which phase of metabolism does the body store?
Metabolism has two phases:
The body stores water, food and oxygen for a time when the substances will be needed. Catabolism – is the phase of metabolism that involves the breaking down of the stored larger substances into smaller one thus releasing the cells stored energy.
What is Phase II reaction?
Phase II reactions include glucuronidation, sulfation, acetylation, methylation, conjugation with glutathione, and conjugation with amino acids (such as glycine, taurine, and glutamic acid). – It is important to understand that these Phase I and II. reactions may occur simultaneously or sequentially.
Where does Phase 2 of drug 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 are the reactions under phase 1 metabolism?
Phase I reactions are broadly grouped into three categories: oxidation, reduction, and hydrolysis. As most small molecule drugs are lipophilic in nature, drug metabolism converts these hydrophobic compounds into more water soluble compounds that can be excreted. Typically, oxidation is the most common phase I reaction.
What is first phase metabolism?
Phase 1 metabolism involves chemical reactions such as oxidation (most common), reduction and hydrolysis. There are three possible results of phase 1 metabolism. The drug becomes completely inactive. … One or more of the metabolites are pharmacologically active, but less so than the original drug.
What are the 3 phases of drug action?
Drug action usually occurs in three phases: Pharmaceutical phase. Pharmacokinetic phase. Pharmacodynamic phase.
What causes slow drug metabolism?
Underlying health conditions can also influence your drug metabolic rate. Some conditions at greater risk of this are chronic liver disorders, kidney dysfunction, or advanced heart failure.
What is Glucuronidation metabolism?
n. a metabolic process by which drugs or other substances are combined with glucuronic acid to form more water-soluble compounds, which are more readily excreted by the kidneys or in bile.