Phase II Reactions

What is phase II reactions?
What are types of phase II reactions? 

What is phase II reactions?
During phase II reactions, the toxic substances or its metabolite is bound with a compound that generally renders the newly synthesized molecule less toxic. This type of reaction is referred to as conjugation. Conjugation is the joining of two substances to form a single molecule, which can increase water solubility and excretion. One of the most important conjugation is conjugation with glucuronidation.

Metabolism

What is metabolism?
How does the toxicant biotransformed?
What are factors affecting metabolism?

What is metabolism?
Metabolism or often referred to biotransformation is a process which result in changing in the chemical structure of the toxic substance. These changes in a variety of tissue such as liver, kidney, lung, skin and GI tract as well. Primary spot for biotransformation is in liver.

Catabolic reaction (Phase I)

This include oxidation, reduction and hydrolisis.

Oxidation
It occurs when a molecule combines with oxygen, loses hydrogen, or loses one or more electrons.

Many toxicants are metabolized by the enzymes cytochrome P-450 reductase and cytochrome P-450 in association with NADPH (co-enzyme: nicotinamide adenine dinucleotide phophate). These enzymes are abundance in endoplasmic reticulum of liver cells for detoxification.

Distribution

What structure plays important role for distribution?
How circulatory system structured?
Is there any barrier for distribution?

What structure plays important role for distribution?
Absorption into and out to bloodstream occurs in the circulatory system which is the capillaries, inhaled toxicants diffuse accross the alveoli.

How circulatory system structured?
It is composed of the heart along with an extensive system of blood vessels that transport oxygen and nutrient-rich blood to the cells. The blood carries oxygen, waste products, nutrients and toxic substances into and out of the bloodstream by active and passive mechanisms.