Alcohol I

Question 1

what are the main components of the structure of alcohol?

Answer 1

it has a methyl CH3 group on one end and a string of carbons and then an hydroxyl (OH) group on the other end

Question 2

What two things need to be present for alcohol production and what is the yielding product? (summarized)

Answer 2

yeast needs to be present to ferment sugars (first converted to glucose, then pyruvate) into ethyl alcohol and carbon diozide

Question 3

What do the yeast use in the alcohol production pathway? how much alcohol can they produce?

Answer 3

yeast use this pathway to generate NAD+ which is a cofactor used in glycolysis to make ATP .. so yeast use this pathway to make energy for themselves

they can only make up to 15% ethanol before the ethanol kills it

Question 4

what is the fermentation process steps?

Answer 4

1. you start with 6 carbon glucose
2. in the process of glycolysis, 2 ADP make 2 ATP and use cofactor NAD+ to make 2 NADH, and produce 2 pyruvate molecules each made of 3 carbons
3. Then pyruvate decarboxylase removes a co2 from the pyruvates (sends it off into atmosphere in form of bubbling) and produces 2 acetaldehyde
4. the acetaldeyde gets formed into 2 ethanols via alcohol dehydrongenase which uses 2 NADH cofactors to make 2 NAD+ which is used up again in glycolysis

Question 5

what is gut fermentation syndrome?

Answer 5

its when a bacteria called saccharomyces cereisaiae causes yeast to form ethanol in your gut

Question 6

how many onzes in one standard drink in canada?

Answer 6

0.6 oz of ethanol

Question 7

how many grams of ethanol are in one ounce given that theres 22.3 grams of ethanol in an ounce?

Answer 7

22.3g/oz X 0.6oz = 13.38 grams

Question 8

how is alcohol absorbed in the stomach?

Answer 8

proteins within the stomach decrease alcohol absorption but the pH of the stomach has nothing to do with the absorption of alcohol

Question 9

how is alcohol absorbed in the small intestine?

Answer 9

theres more absorption at the level of the small intestine after it leaves the stomach, thats why if you drink on a fuller stomach absorption will take more time before empying out into the small intestine
- alcohol with co2 bubbles also increase absorption by increasing transit from stomach to small intestine

most of the absorption happens at the small intestine

Question 10

What is the Mellanby effect?

Answer 10

indicates acute tolerance to the effects of alcohol (happens right away)

shown in graph of ethanol absorption in humans

humans appear more impaired approx 30 minutes after dose administration with a mean BAC of around 68 mg/dl, and describe feelings of euphoria, happiness, friendly..etc.. but then at around an hour after dose administration they hit the peak BAC level (83 mg/dl) and then start dropping in BAC% as body starts to metabolize the ethanol. While on its way down, at 68mg/dl the person starts feeling lethargic, sick, grumpy, depressed…etc.. negative moods

this is the Mellanby effect that the same dose differs n behaviour produced depending on whether it is in the rising phase vs. the decreasing phase

Question 11

what is the biphasic effect of ethanol in animals?

Answer 11

the biphasic effect:

• at low doses, ethanol can increase locomotion and acts as a moto stimulate, this is likely due to increased dopamine levels
• at high doses, it is a sedative/depressant and these seem to be mediated via effects on receptors for GABA and glutamate

Question 12

what kind of behaviours are disrupted by ethanol in low concentrations?

Answer 12

• at low concentrations complex, abstract, and poorly learned behaviours are disrupted

Question 13

what kind of behaviours are disrupted by ethanol in high concentrations?

Answer 13

better learned and basic behaviours are affected, as well as motor control

Question 14

what is acute death from overdose of ethanol typically due to?

Answer 14

respiratory depression, coma or inhalaiton of vomit

Question 15

what is disinhibition? when does it occur?

Answer 15

inhibitions are reduced

some behaviours are increased because of this like verbal expression, socializing and risky sexual behaviours
disinhibition is linked to increase dopamine levels in the reward pathway
can be seen in most organisms from simple worms to humans

at certain dose

u experience euphoria and happiness and anxiety is diminished

when ur sober ur PFC controls certain thoughts, and words that are innapropriate for the context from coming out but alcohol prevents this and inhibits the inhbitory pathways therefore making them excitatory

Question 16

How does ethanol increase sociability and decrease anxiety in animal models?

Answer 16

at low doses, ethanol increases social interaction and theres a bigger effect of this in adolscents

ethanol also relieves anxiety when mice are placed in unfamiliar areas and you see more singificant social interaction when alcohol levels increase in adolescents

can be seen as overcoming the inhibitory effects of an unfamiliar environment on social interaction

Question 17

what is BAC? how is it calculated?

Answer 17

BAC is the blood-alcohol concentration

it is a grams of ethanol per 100ml of blood

so a BAC of 0.08 is 0.08 grams of ethanol in 100ml of blood which is the legal limit

to calculate, you divide the number of grams of ethanol ingested by the volume in which it can distribute

Question 18

What is the BAC of concentration needed to kill you?

Answer 18

0.4g or 0.5 grams and higher of alcohol per 100ml of blood

Question 19

why is the BAC of men lower than women for the same amount of alcohol ingested?

Answer 19

men have more water than women which means the ethanol can be more diluted in their system

women have less water so alcohol affects them more

this is because men have more muscles, which retain more water, and women typically have less muscle, and retain less water

Question 20

how do you estimate blood alcohol concentrations?

Answer 20

first you convert the ounces of alcohol in a standard drink into grams = 13.4 grams

then you figure out how much % of a typical man and typical woman is composed of water. You do this so you can see how much of the ethanol in one drink is diluted in an average person

so an average man is 58.3% water
and an average woman is 48.5% water

Now we want to multipy the % water by the weight of the average male or female to get the total liters of water they store in their bodies
one litre of water weighs 1kg so:
a 200 pound (90.7kg) woman X 0.485 = 44L
a 200 pound (90.7kg) man X 0.583 = 52.9L

Now you need to know how much ethanol in % is in the total liters of water stored in the average man and average woman

13. 4g/44L = 0.30g/L = 0.030g/100mL = 0.030% (for a woman)
14. 4g/52.9L = 0.25g/L = 0.025g/100mL = 0.025% (for a man)

so for an average woman theres 0.030% alcohol in their body water and for an average man its 0.025% alcohol

now we need to convert this to blood values

blood is 80.6% water so you multiply alcohol-water values by this number to get blood alcohol concentration

0. 03 x 0.806 = 0.024 (for women)
1. 025 x 0.806 = 0.20 (for males)

these are blood alcohol concentrations

Question 21

what is the percentage of alcohol metabolized in the liver? how much of it goes unmetabolized?

Answer 21

most of alcohol gets metabolized via first pass metabolism

90% is metabolized by liver
2% excreted unchanged in breath, skin and urine

and some gets metabolized in the stomach

Question 22

what occurs during the metabolism of alcohol? what are the major enzymes involved? where does it occur? what are two enzymes that pitch in to metabolize alcohol when theres a large amount of ethanol in the liver?

Answer 22

alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH2) are the major enzymes

most metabolism occurs in the liver but small amounts are metabolized elsewhere like stomach

the enzyme CYP2E1 normally metabolizes less than 20% usually but percentage increases with heavy drinking

catalase (another enzyme) plays a minor role overall. May produce acetaldehyde in the brain, may induce acute increase in alcohol metabolism

CYP2E1, and catalase dont play a big role in metabolism of ethanol unless theres alot and then they speed up the process a bit

when CYP2E1 and catalase start to metabolize more ethanol (usually bc theres lots) they make more acetaldehyde which is toxic to the body

therefore chronic drinkers have higher acetalaldehyde amount

Question 23

How does the liver metabolism of ethanol show saturation? and what is the reason?

Answer 23

if you give the liver alot of alcohol, it wont metabolize all of it for a while. The ability for enzymes to metabolize ethanol is quickly overwhelmed and not all of it can get metabolized the first time through the liver

the reason for this is because enzymes in the liver need the cofactor NAD+ to work

metabolizing 1 standard drink requires a large quantity of NAD+ and NAD+ isn’t always available in large amounts because other processes in the body require it as well

Question 24

what does NAD+ limit the availability of metabolism to?

Answer 24

about 8g/hour (one standard drink is 13.8g) so about 2 hours to metabolis one drink

Question 25

what is the kinetics of metabolism in alcohol?

Answer 25

instead of a proportion of ethanol being removed in a given amount of time, there is a constant amount of ethanol removed in a given amount of time

there is so much ethanol that all enzymes involved in its metabolism are completely occupied and there is no excess capacity in the system

the metabolic pathway operates at a max level with a modest amount of alcohol in the system

regardless of the dose or BAC level, metabolism drops roughly the same amount when metabolized an hour after absorption

Question 26

what does metabolism depend on? what is the average persons metabolism rate? what is the value of BAC drop her hour after injesting alcohol in Canada for law?

Answer 26

metabolism depends on alcohol expereince. experienced drinkers tend to metabolize more quickly due to metabolic tolerance

the average drinker metabolism rate is 0.017 BAC decline per hour

in canada and in courts, they use 0.015 BAC per hour as the average

so 0.015 grams of alcohol get metabolised per 100 ml per hour

Question 27

how much BAC drop in an average male and female after an hour?

Answer 27

in an average male:
0.020 (BAC after one drink) - 0.015 (avg. BAC drop in one hour) = 0.005 = 0.005/0.020 = 25% of ethanol left in system to metabolize

in average female

0.024 - 0.015 = 0.009 = 0.009/0.024 = 37.5% ethanol left

after one hour the male has metabolized 75% (100-25) of the single drink, and the female has metabolized 62% (100-37.5)

Question 28

What do breathalyzers measures? how many parts of ethnaol is in blood compared to lungs?

Answer 28

[alcohol]blood: [alcohol]exhaled breath = 2100:1

so theres 2100 times more concentration of ethanol in blood than in breath

the breathalyzer measures the 1 part of ethanol in breath

the breathalyzer records the amount of non-metabolized ethanol expired from the lungs

Question 29

which enzymes are involved in metabolism of alcohol? what byproducts do they produce?

Answer 29

ethanol gets formed into acetaldehyde by alcohol dehydrogenase and then acetaldehyde gets formed into non-toxic acetate via aldehhyde dehydrogenase

Question 30

what happens when you have a mutation in the aldehyde dehydrogenase gene?

Answer 30

you get more build up of acetylaldehyde in the GI tract which is toxic and causes blushing, sweating, and increased risk of esophageal cancer… common in asians

Question 31

what are the 3 stages of metabolism for ethylene glycol (aka antifreeze)?

Answer 31

first stage: CNS depression –> appears like you’re drunk, can lead to coma
second stage: cardiopulmonary dysfunction –> acidosis (drop in pH of blood) can be fata, and can head to hyperventilation, heart arrythmia and pulmonary edema(swelling in lungs/water in lungs)
third stage: renal dysfunction (kidney failure), urine production stops, can occur few days after contact

30 ml of this can cause death

Question 32

what are the toxic byproducts formed in ethylene glycol metabolism? what do they do and what enzyme breaks them down?

Answer 32

etheylene glycol is converted to glycoaldehyde by alcohol dehydrogenase, and then glycoaldehyde is further made into to glycolic acid and oxalic acid by ADH as well

glycolic acid acid turns into oxalic acid over time and oxalic acid can bind with calicum to form crystal that precipitate through body including kidneys and lungs

glycolic acid lowers the pH in the blood which can lead to alot of more problems with heart rate etc..

Question 33

how is methanol (formic acid) metabolised? what are the initial symptoms and then what happens over time? what kind of damage does it do?

Answer 33

formic acid is responsible for optic nerve damage because it disrupts mitochondrial function

as little as 10ml of it can cause blindness and 30ml can cause death

formic acid also produces acidosis by lowering pH of blood

as time passes (6-30hrs) and more is metabolized, the symptoms of vision loss and acidosis become more serious

respiratory failure or sudden resp. arrest are the most common causes of death from methanol.

Question 34

what is the enyme involved in methanol metabolizm and what are the byproducts?

Answer 34

enzyme involved in making methanol into formaldehyde (DANGEROUS PERSERVATIVE) by alcohol dehydrogenase and then ADH also takes formaldeyde and turns it into formic acid which can cause acidosis and blindness

formic acid is worse than formaldehyde even though they are both dangerous

Question 35

how is rubbing alcohol metabolised? what enzyme metabolizes it and what are the byproducts? what does it do ?

Answer 35

acetone/isopropanol are CNS depressants

they are safe at low levels

at high levels, they cause vomitting and coma

Question 36

what is an older way of preventing methanol poisoning? what is a problem with this method?

Answer 36

the older method of preventing posioning is to flood the body with ethanol because ethanol is more favoured to ADH than methanol is, so ADH will bind to all of the ethanol and leave no room for methanol therefore, excreting it out of the system and producing less to little amounts of the dangerous metabolites

the problem with this is that some people cant handle ethanol in large amounts i.e. their liver is messed up or they have other problems so its not a good idea

Question 37

what is a newer method of preventing methanol and ethylene glycol poisoning?

Answer 37

inhibiting alcohol dehydrogenase with fomepizole, a competitive inhibitor of the enzyme

used in ethylene glycol and methanol poisoning

it has a longer duration of action than flooding the system with ethanol which is good but it is more expensive

minimal adverse effects compared to flooding the system with methanol