OCR A2 Biology structure and function of the Liver

Quick Revision Resource :)

HideShow resource information
  • Created by: Katie
  • Created on: 30-05-11 14:27
Preview of OCR A2 Biology structure and function of the Liver

First 385 words of the document:

The liver ­ Enzyme action in the liver
Why is P450 most concentrated in the Endoplasmic reticulum
Why many medical drugs have different side effects on different people
Why the P450s are not identical in every person
Liver disease
Why many medical drugs have different side effects on different people and Why the P450s
are not identical in every person
Cytochrome P450 is a family of the body's more powerful Detox Enzymes. Over 60 key
forms are known, with hundreds of genetic variations possible, producing a wide variety of
susceptibility to specific toxins.
There are over a thousand different CYPs, although the number in each person is only
about fifty.
In different people and different populations, activity of CYP oxidases differs. Genetic
variation in a population is termed 'polymorphism' when both gene variants exist
with a frequency of at least one percent. Such differences in activity may have
profound clinical consequences, especially when multiple drugs are given to a patient.
Why is P450 most concentrated in the Endoplasmic reticulum
Human CYPs are primarily membrane-associated proteins, located either in the inner membrane of
mitochondria or in the endoplasmic reticulum of cells. CYPs metabolize thousands of endogenous and
exogenous chemicals. Cytochrome P450 enzymes are present in most tissues of the body, and play
important roles in hormone synthesis and breakdown (including oestrogen and testosterone
synthesis and metabolism), cholesterol synthesis, and vitamin D metabolism
Liver disease
A build-up of fat occurs within liver cells in most people who regularly drink heavily. In itself, fatty
liver is not usually serious and does not cause symptoms. Fatty liver will usually reverse if you stop
drinking heavily. Drinking too much alcohol can lead to three types of liver conditions - fatty liver,
hepatitis, and cirrhosis. Any, or all, of these conditions can occur at the same time in the same person.
Hepatitis means inflammation of the liver. The inflammation can range from mild to severe. Cirrhosis
is a condition where normal liver tissue is replaced by scar tissue (fibrosis). The scarring tends to be a
gradual process. The scar tissue affects the normal structure and regrowth of liver cell

Comments

No comments have yet been made

Similar Biology resources:

See all Biology resources »See all resources »