Alcohol March 2015

Yeast and Alcohol For thousands of years, people have used a fungus called baker’s yeast, Saccharomyces cerevisiae, to ferment ethanol (drinking alcohol) and bake bread. The bubbles in champagne, for example, owe to the activity of this yeast. When yeast are causing bread dough to rise, do they also make alcohol?

Fermentation When glucose is broken down by glycolysis, the electron carrier NAD + is converted into NADH. This NADH can be used in the electron transport chain to make ATP if oxygen is available. But what about when there’s no free oxygen available? In that case, the organism needs to recycle the NADH back to NAD + ! In addition, there needs to be a way to get rid of the pyruvate. In yeast, this is done by making carbon dioxide and ethanol – the bubbles and alcohol in alcohol fermentation. These bubbles are also what causes bread dough to rise.

Distillation Once yeast make enough alcohol to raise the concentration to about 15%, they stop fermenting; too much alcohol would kill them. To make drinks with a higher percentage of alcohol than that, we use distillation. Because alcohol evaporates more easily than water, heating an alcoholic drink and capturing the steam will separate it from water. (Note: Improper distillation carries a risk of explosion.)

Proof and Percentage Alcohol Concentration As a general rule, which, if any, of the following contains the most alcohol? A 12 oz. can of beerA 5 oz. glass of wineA 1.5 oz. shot of whiskey

Proof/Percentage Alcohol by Volume Because the beer has the lowest concentration of alcohol and the whiskey has the highest concentration of alcohol, but a single drink of whiskey is smaller than a can of beer… all three servings have about the same total alcohol content. By and large, an alcoholic drink is an alcoholic drink; wine is only “safer” in that people may drink it more slowly than shots. Alcohol content can be measured in percentage by volume or by proof. Proof is just twice the percentage by volume. If a drink is 50% alcohol, it is 100 proof. Proof is not a measure of quality. Even high proof beverages can contain impurities that increase hangover pain, and some can have a deceptively mild taste, making it easy to become intoxicated quickly without realizing the high alcohol content. Drinking cups not specifically meant for a given drink do not take proof into account. Be careful when drinking from large cups.

Blood Alcohol Concentration (BAC) What is the legal limit for Blood Alcohol Concentration for driving in most U. S. states? A)8% (8/100 of your blood is alcohol) B).8% (8/1000 of your blood is alcohol) C).08% (8/10,000 of your blood is alcohol) D).008% (8/100,000 of your blood is alcohol) Assuming no problems with alcohol metabolism, how many drinks would it take a 140-lb woman to reach this level? What about a 220-lb man?

Blood Alcohol Concentration

Safer Drinking Habits Always have a designated driver at events that involve alcohol. Do not drink too much at one occasion. Very generally, binge-drinking is defined as >4 drinks within 2 hours for men, or >3 drinks within 2 hours for women. Never drink on an empty stomach; food slows down the rate of alcohol absorption and reduces the risk of alcohol poisoning. Avoid drinking games, and never drink to unconsciousness.

What Causes Hangovers? Which of the following play a role in hangovers? Choose all that apply: A)Dehydration B)Poisonous molecules the body makes from alcohol C)Poisonous molecules found with alcohol in drinks D)Low blood sugar Will coffee reduce the symptoms of a hangover?

Alcohol Metabolism Alcohol dehydrogenase (ADH) converts ethanol into poisonous acetaldehyde, which is 20 times more toxic than alcohol itself. This happens mostly in the liver, but also in the stomach lining, where alcohol is absorbed. The acetaldehyde dehydrogenase enzyme (ALDH) then converts the acetaldehyde into relatively harmless acetate (same stuff as vinegar) in the liver. People without a working ALDH enzyme are highly sensitive to alcohol and can suffer brain damage quickly from alcohol consumption!

Alcohol and the Liver Long-term alcohol consumption damages the liver. This damage3 can take multiple forms: Fatty liver: Buildup of fat in liver cells. Can cause inflammation Hepatitis: Inflammation of the liver; can lead to jaundice and eventually liver failure. Cirrhosis: Scarring and hardening of the liver. Eventually can be fatal.

Alcohol and Nutrition Because alcohol is a form of empty calories, it can displace healthy foods from the diet and lead to weight gain. In addition, because alcohol is a diuretic, it causes loss of water- soluble vitamins and minerals, in particular B vitamins and zinc. Wernicke-Korsakoff syndrome: nerve damage, paralysis, memory loss – brain damage.

Fetal Alcohol Syndrome Alcohol is a teratogen – that is to say, it can cross the placenta and cause birth defects in a developing embryo in the form of Fetal Alcohol Syndrome, which can affect facial and brain development. Some studies suggest that very modest alcohol consumption during pregnancy (1 glass of wine a week) is harmless. However, the Centers for Disease Control advise caution in this – there is no guaranteed safe amount.

Alcohol Dependency and Abuse Destructive use of alcohol can lead to dependence. A person begins needing more alcohol to achieve the same sensation, and suffers withdrawal symptoms, such as nausea, insomnia, anxiety, or even tremors and seizures when they go without drinking. Alcohol dependency develops over time, and cannot be reversed quickly or easily. Support groups, antiabuse drugs, and therapy can help, but long-term abstinence from alcohol is always challenging for those who have struggled with alcohol abuse. Warning signs of alcohol dependency include unsuccessful efforts to cut down on drinking, reduction in important daily activities for alcohol use, and episodes of binge-drinking and hangovers.

Benefits of Red Wine? Some studies suggest that phytochemicals from the skin of grapes, such as resveratrol, found in red wine, can have healthy antioxidant effects and reduce the risk of heart attacks. Our text uses this to explain the French Paradox. The French Paradox is that on average, the French eat a diet with a great deal of cholesterol and saturated fat, yet have lower risks of heart disease than Americans. They also drink more red wine. Is this line of reasoning sufficient to conclude that drinking red wine is responsible for the better health of the French? What else could be at play here? Given what I’ve said above, is there any way to get the benefits of resveratrol without drinking red wine?