Lecture 5 Flashcards
what is alcohol?
are molecules containing 1 or more hydroxyl groups (OH-) attached to a carbon atom (C) that can be attached to other C atoms
- ethanol is an alchohol widley consumed by humans
how is ethanol made?
- is a metabolite made by brewers yeast during the metabolism of sugars to extract energy for their needs
- fermentation requires the absence of oxygen
- cell growth is carefully monitored in fermentation vats since excessive alchohol levels are toxic to yeast
Alcohol and ancient egypt (3000BC-300BC)
- early producers of beer from barley
- the god Osiris taught people to make beer
- used for currency of trade
- strong religious element
Alchohol and Ancient rome
- wine had large economic value
- strong social acceptance
- excess drinking criticised moderation is a virtue
types of alchohol: Beer
- most popular beverage
- made from starchy grains suh as barley and wheat
- ancient beers: thick and fibrous
- modern beers: clear and carbonarted, higher alcohol content
types of alchohol: wine
- produced from fruit commonly grapes also berres
- longer fermentation time than beer, higher alcohol content than beer
Types of alcoholic beverages: spirits
- produced through distillation
- technically quite complex
- boiling a fermented produts and capturing the steam in a condenser which then drips down and is collected
- vodka, rum, gin
Types of Alcohlic beverages: fortified wines
- wine to which spirits have been added
- orginiated c1700s in countirs with strong maritime economis
eg port, sherry, vermouth
What are the pharmcokinetics of alcohol?
- ethanol displays what chemists call amphipathic or amphilphilic character
(combination of fatloving and water loving properties
Pharmokinetics of alcohol - Absorption
- after oral consumption alcohol is quickly absorbed into the blood
- absorbed mostly from the upper intestine and the stomach
Pharmokinetics of alcohol - Distraibution
- wide distrabiution via blood
- manly distrbutes into total body water TBW
- vol approx 40-45 in adults
- alcohol readily crosses membranes although penetrance into body fat is poor
- explains why increased peak BAC seen in females then males
Pharmokinetics of alcohol - Metabolism
- in gut wall (minor) and livere (major) protects the body against EtOH
- mainly 95% of alcohol dehydrogenase and alldehyde dehydrogenase
- inherited polymorphisms in ADH and ALDH genes influnce rate at which EtOH and acetaldehyde are metabolised
Pharmokinetics of alcohol - excretion
- a tiny amount og EtOH is excreted directly by kidneys (in urine)
- EtOh s excretd in exhaled breath
Pharmacodynamics of Alcohol: Effects on the Brain
- depress functioning of the brain to produce calming, relaxation, disinhibtion, drowsiness or coma/death
Mechanism of Etoh on brain functions
- low potency
- EtOH mainly produce nonspecfiic effects on neuronal membrane fluidity
- EtOH receptors are often ion channels that regulate ion flows into nerve cells