The chemical that goes by the common name "alcohol" is more properly called ethanol, or ethyl alcohol. It's a popular drug, used socially to produce feelings of relaxation and reduce inhibitions. Sucrose, meanwhile, is the chemical name for table sugar. As components of diet, both sucrose and alcohol have notable effects upon the body.
Chemistry of Alcohol
The ethanol molecule consists of a short chain of atoms, with the chemical formula C2H6O. Ethanol is highly water-soluble, which is why it dissolves in any concentration in water, allowing beverages to contain anywhere from zero to nearly 100% alcohol. Unlike nutritional molecules in food --- carbohydrates, protein and fat --- alcohol isn't absorbed strictly in the intestine. Alcohol absorption actually begins in the mouth, and the absorbed alcohol moves directly into the bloodstream.
Chemistry of Sucrose
Biochemists classify the sucrose molecule as a disaccharide, meaning it's made up of two separate sugar units chemically bonded together. In their book "Biochemistry," Drs. Mary Campbell and Shawn Farrell explain that the smaller sugar molecules glucose and fructose, when linked together, produce sucrose, or table sugar. Once an individual ingests table sugar, enzymes in the gut split the sucrose into fructose and glucose, and these smaller sugars are absorbed into the bloodstream.
Considerations
With regard to cellular utilization of alcohol and sucrose, once alcohol and the components of sucrose --- glucose and fructose --- get into the bloodstream, cells can take them up. Cells then burn the sugars from fructose or the alcohol molecule to provide energy. Alcohol gets converted into acetic acid, which is the molecule responsible for the smell and acidity of vinegar, Campbell and Farrell explain. The cells then burn acetic acid for energy.
Effects
Both sucrose and alcohol lead to the release of pleasure molecules in the brain, which is one of the reasons that individuals find both sugar and alcohol to be addictive --- though alcohol is much more so. Research published in the "Journal of Neurophysiology" in 2004 reported that both sucrose and alcohol activate identical pathways in the brain, leading to release of reward molecules that send chemical signals essentially praising the body for "good behavior."
Expert Insight
Because the cells can burn acetic acid, formed from alcohol, for energy, alcohol contains calories. While carbohydrates, including sucrose, contain 4 Calories per gram, alcohol contains closer to 7. This makes alcohol more similar to fat --- which contains 9 Calories per gram --- than it is to any of the other macronutrients. Drs. Reginald Garrett and Charles Grisham, in their book "Biochemistry," note that structurally, alcohol is more similar to fat than it is to protein or carbohydrate, so the similar caloric content makes sense.
References
- "Biochemistry"; Mary Campbell, Ph.D., and Shawn Farrell, Ph.D.; 2005
- "Journal of Neurophysiology"; Alcohol activates a sucrose-responsive gustatory neural pathway; C. Lemon et al.; July 2004
- "Biochemistry"; Reginald Garrett, Ph.D., and Charles Grisham, Ph.D.; 2007
