Author: James Anderson

Alcohol Definition, Formula, & Facts

alcohol in science

As the length of the alcohol increases, this situation becomes more pronounced, and thus the solubility decreases. This table shows that alcohols (in red) have higher boiling points and greater solubility in H2O than haloalkanes and alkanes with the same number of carbons. It also shows that the boiling point of alcohols increase with the number of carbon atoms.

  1. Because alcohol affects emotional centers in the limbic system, alcoholics can become anxious, depressed, and even suicidal.
  2. After pro- longed use, more and more alcohol is needed to achieve the same level of euphoria as before.
  3. How does the chemistry of alcohol work on the chemistry of the brain?
  4. Many of the articles in this collection take a medical view of alcohol, demonstrating how scientific knowledge of alcohol in relation to human physiology has advanced during the past century.

It all depends on the amount of alcohol consumed, a person’s history with alcohol and a person’s personality. This article covers the structure and classification, physical properties, commercial importance, sources, and reactions of alcohols. For more information about closely related compounds, see chemical compound, phenol, and ether. There is a group of drug therapies aimed at attacking GABA receptors and the dopamine and serotonin pathways. For example, Baclofen is an approved GABA agonist for seizures that has shown to decrease craving and anxiety in alcohol addicts (7). Similarly, a low dosage of topira- mate, a natural anticonvulsant, can be used to dampen down excitability and maintain abstinence by reducing the amount of dopamine produced in the reward pathway during alcohol consumption (8).

How Alcohol Leaves the Body

This page defines an alcohol, and explains the differences between primary, secondary and tertiary alcohols. It examines in some detail their simple physical properties such as solubility and boiling points. Alcohols are compounds in which one or more hydrogen atoms in an alkane have been replaced by an -OH group. Alcohols fall into different classes depending on how the -OH group is positioned on the chain of carbon atoms.

alcohol in science

The -OH ends of the alcohol molecules can form new hydrogen bonds with water molecules, but the hydrocarbon “tail” does not form hydrogen bonds. This means that many of the original hydrogen bonds being broken are never replaced by new ones. Fermented beverages clearly eased the difficulties of everyday life—the workers who built the pyramids of ancient Egypt and Mesoamerica were paid in beer. Alcohol also knitted together, or “lubricated,” the social fabric of cultures by bringing humans together and warming them up to one another. Although the damage to the GABA pathway is important, a significant consequence of alcohol is its interference with the reward pathway.

Alcohol: An Astonishing Molecule

The medulla, or brain stem, controls or influences all of the bodily functions that are involuntary, like breathing, heart rate, temperature and consciousness. As alcohol starts to influence upper centers in the medulla, such as the reticular formation, a person will start to feel sleepy and may eventually become unconscious as BAC increases. If the BAC gets high enough to influence the breathing, heart rate and temperature centers, a person will breathe slowly or stop breathing altogether, and both blood pressure and body temperature will fall. If you have seen someone who has had too much to drink, you’ve probably noticed how drinking alcohol causes definite changes in that person’s performance and behavior.

But where does the college drinking culture come from and where can we draw the thin line between being in control of alcohol and having alcohol control you? Approximately one out of five college students meet the National Institute on Alcohol Abuse and Alcoholism’s criteria for alcohol dependence (1). Even those who don’t drink can be one of the 599,000 students that are often unintentionally injured in alcohol-related situations (1). One of the causes behind these alarming statistics is simply the biology of the adolescent brain. College is usually where the last stage of brain development, the maturation of the prefrontal cortex, takes place. The prefrontal cortex is a region key to control and decision-making.

The effect of van der Waals forces

However, when the molecules are mixed, new hydrogen bonds are formed between water molecules and ethanol molecules. In the IUPAC system, alcohols are named by changing the ending of the parent alkane name to -ol. Alcohols are classified according to the number of carbon atoms attached to the carbon atom that is attached to the OH group. In both pure water and pure ethanol the main intermolecular attractions are hydrogen bonds. The articles here highlight the modern versions of drinks with very ancient pedigrees, including grape wine and barley and wheat beers.

Similarly, grape wine is central to Western religions, rice and millet beers held court in ancient China, and a fermented cacao beverage was the beverage of the elite in pre-Colombian Americas. These boiling points are compared with those of the equivalent alkanes (methane to butane) with the same number of carbon atoms. Alcohol has two noticeable effects on the hypothalamus and pituitary gland, which influence sexual behavior and urinary excretion. When ethanol is oxidized to acetic acid, two protons and two electrons are also produced. The acetic acid can be used to form fatty acids or can be further broken down into carbon dioxide and water. The BAC increases when the body absorbs alcohol faster than it can eliminate it.

For example, Naltrexone is an opioid drug that blocks opioid receptors. Its interfer- ence with the dopamine pathway was reported in 1997 (9), and a series of subsequent clinical trials have shown a high degree of efficacy (10). The patterns in boiling point reflect the patterns in intermolecular attractions. All of alcohol’s effects continue until the ingested alcohol is eliminated by the body.

In each case there is only one linkage to an alkyl group from the CH2 group holding the -OH group. Methanol, CH3OH, is counted as a primary alcohol even though there are no alkyl groups attached to the the -OH carbon atom. The brain impulses that initiate muscle movement originate in the motor centers of the cerebral cortex and travel through the medulla and spinal cord to the muscles. As the nerve signals pass through the medulla, they are influenced by nerve impulses from the cerebellum.

Methanol (CH3OH) and ethanol (CH3CH2OH) are the first two members of the homologous series of alcohols. Alcohol, any of a class of organic compounds characterized by one or more hydroxyl (―OH) groups attached to a carbon atom of an alkyl group (hydrocarbon chain). Alcohols may be considered as organic derivatives of water (H2O) in which one of the hydrogen atoms has been replaced by an alkyl group, typically represented by R in organic structures. For example, in ethanol (or ethyl alcohol) the alkyl group is the ethyl group, ―CH2CH3. The hydrocarbon chains are forced between water molecules, breaking hydrogen bonds between those water molecules.

Alcohol affects various centers in the brain, both higher and lower order. The centers are not equally affected by the same BAC — the higher-order centers are more sensitive than the lower-order centers. As the BAC increases, more and more centers of the brain are affected. In the United States, you must be 21 years or older to buy alcoholic beverages, and there are penalties for serving or selling alcoholic beverages to minors. Another series of perhaps more effective drugs directly target the reward pathway.

Other genes are involved in the so-called hormetic response, in which low-level exposure to a potential poison might contribute to positive physiological effects. We primates, of course, are no exception, but among this order, perhaps no other animal most elegantly demonstrates its penchant for alcohol than the Malaysian pen-tailed treeshrew. Among the earliest primates on the planet (emerging some 55 million years ago), this creature feeds principally on fermented palm nectar, drinking the human equivalent of nine glasses of wine a night—without obvious signs of inebriation. This shrew’s diet sets the pattern for alcohol consumption among primates for millions of years. In addition to coordinating voluntary muscle movements, the cerebellum also coordinates the fine muscle movements involved in maintaining your balance.

How Alcohol Enters the Body

The energy released when these new hydrogen bonds form approximately compensates for the energy needed to break the original interactions. In addition, there is an increase in the disorder of the system, an increase in entropy. Consider a hypothetical situation involving 5-carbon alcohol molecules. Small alcohols are completely soluble in water; mixing the two in any proportion generates a single solution. However, solubility decreases as the length of the hydrocarbon chain in the alcohol increases. At four carbon atoms and beyond, the decrease in solubility is noticeable; a two-layered substance may appear in a test tube when the two are mixed.

This long and often polarizing history is described in this in-depth collection of articles from the Scientific American archives. Finally, we add enough hydrogen atoms to give each carbon atom four bonds. Notice that the complexity of the attached alkyl group is irrelevant.