Fats and oils are organic compounds that, like carbohydrates, are composed of the elements carbon C , hydrogen H , and oxygen O , arranged to form molecules. There are many types of fats and oils and a number of terms and concepts associated with them, which are detailed further here. In baking, lipids are generally a synonym for fats.
Triglycerides is another chemical name for the most common type of fats found in the body, indicating that they are usually made up of three tri fatty acids and one molecule of glycerol glycerine is another name as shown in Figure 3. The mono and diglycerides that are used as emulsifiers have one and two fatty acids respectively. Each kind of fat or oil has a different combination of fatty acids.
The nature of the fatty acid will determine the consistency of the fat or oil. For example, stearic acid is the major fatty acid in beef fat, and linoleic acid is dominant in seed oils. Fatty acids are defined as short, medium, or long chain, depending on the number of atoms in the molecule.
The reason that some fat melts gradually is that as the temperature rises, each fatty acid will, in turn, soften, as its melting point is reached. Fats that melt all of a sudden mean that the fatty acids are of the same or similar type and have melting points within a narrow range.
An example of such a fat is coconut fat: one second it is solid, the next, liquid. Rancid is a term used to indicate that fat has spoiled. Unsalted butter, for example, will go rancid quickly if left outside the refrigerator, especially in warm climates.
Oxidation exposure to air causes rancidity in fats over time. This is made worse by combination with certain metals, such as copper. This is why doughnuts are never fried in copper pans! Some oils contain natural antioxidants, such as tocopherols vitamin E is one kind , but these are often destroyed during the processing. As a result, manufacturers add synthetic antioxidants to retard rancidity.
Saturated and unsaturated refer to the extent to which the carbon atoms in the molecule of fatty acid are linked or bonded saturated to hydrogen atoms. One system of fatty acid classification is based on the number of double bonds. Figure 3 Oleic Acid. Carbohydrates are classified into three groups according to the number of sugar or saccharide molecules present:.
Lipids are a class of substances that are insoluble in water and other polar solvents , but are soluble in nonpolar substances such as ether or chloroform. There are three major groups of lipids:. Proteins represent a class of molecules that have varied functions.
Eggs, muscles, antibodies, silk, fingernails, and many hormones are partially or entirely proteins. Although the functions of proteins are diverse, their structures are similar.
All proteins are polymers of amino acids; that is, they consist of a chain of amino acids covalently bonded. The bonds between the amino acids are called peptide bonds, and the chain is a polypeptide, or peptide. One protein differs from another by the number and arrangement of the 20 different amino acids.
The fourth bond of the central carbon is shown with the letter R, which indicates an atom or group of atoms that varies from one kind of amino acid to another. Organic molecules are compounds that contain carbon-hydrogen bonds and are found in living things. The major classes of organic molecule are carbohydrates , proteins , lipids and nucleic acids. Article Summary: What are the different kinds of lipid molecules? What is the difference between saturated and unsaturated fats?
Read on and discover. Unsaturated fats oils :These fats are mostly derived from plant sources. This is why unsaturated fats are liquid at room temperature.
Fats and oils are made from two kinds of molecules:. Saturated fats: These types of fat are mostly derived from animal sources.
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