If the double bond is at the end of a chain the molecule is called an aldehyde. If the double bond occurs away from an end the compound is called a ketone. Organic Acids have a COOH group with a weakly held hydrogen atom that can be ionized in water. Most organic acids are very weak. A neutralization reaction occurs and leaves the organic equivalent of a salt.
Esters usually have a pleasant fruit-like flavor.
Carbohydrates are compounds of carbon, hydrogen, and oxygen that have two atoms of hydrogen for each atom of oxygen. Two simple sugars are often linked to form a disaccharide . Polysaccharides are complex sugars consisting of chains of the simple sugars. In living things, polysaccharides serve both as structural components and as a source of stored energy. Starch is another polysaccharide of 300 to 1000 glucose units that is used to store energy.