Metabolism of alcohol
The sciency bit...
Ethanol ---------> Ethanal ---------> Ethanoate (enters Krebs cycle for ATP)
Alcohol dehoydrogenase Aldehyde dehydrogenase
Reduced NAD Reduces NAD
What it means...
Normally the small lipid-soluble alcohol molecules can easily diffuse across plasma membranes causing considerable damage, so they need to broken into harmless substances.
Regular intake of alcohol can damage liver cells - but breaking down ethanol oxidises NAD so other substances which need to be oxidised cannot e.g. fatty acids. These accumulate and are converted to fats and deposited in the liver. More fat = more alcohol consumed.
Fat is stored in the hepatocytes severely reducing their efficiency to do tasks. This is known as a fatty liver.
These effects combined with ethanol effects causes cirrhosis of the liver.
Liver cells are destroyed by ethanol, the lobule shape is distorted and large amounts of fibrous tissue is laid down. Blood from the hepatic portal vein doesn’t flow don the sinusoids, instead it flows into the hepatic vein.
Another e.g. of having cirrhosis is that ammonia can no longer be converted to urea by the hepatocytes, so ammonia accumulates in the blood and damages CNS. This can result in death or coma.
Hepatocytes perform wide variety of functions, so damage to them affects many aspects (shown in ammonia e.g.)