The word "lipid" encompasses both fats and oils. Both animals and plants need fats as a form of storable food and also to allow various functions to be performed. The fats are not soluble in water like other energy sources, such as glucose. The solid form of the lipid is the fat, while the liquid form of a lipid is the oil. Most people do not think of plants as being fatty, but they do contain some fats that they need for their biological processes.
Lipids in Plants
Lipids are used to create the structural membranes that all life forms are made out of. Lipids are commonly found in plant seeds, according to Cyber Lipid. The majority of this fat is found in the embryo and endosperm, which makes sense, since the endosperm is the food source of the plant embryo as it grows. Some seeds, such as sunflower seeds, store most of their fat in both the cotyledon and the embryo. Lipids have an insulating function that protects seeds from the cold when they are resting in the soil during the winter, waiting to germinate in the spring.
Plant fats are mostly triglycerides. A few species of plants, such as desert shrubs, use liquid wax as fats, according to Cyber Lipid. The triglycerides are easily digestible by most organisms and can easily be digested in the seed, according to 123 Help Me.
When a plant creates energy, much of this energy is used to replace the energy that the plant lost. However, there is some energy left over that is stored initially as carbohydrates, according to Cyber Lipid. These carbohydrates are mostly composed of oxygen. But when they are changed into lipids, they become carbon-based molecules. They contain both glycerol -- a form of alcohol -- and three fatty acids, according to 123 Help Me.
Different plant species have different kinds of fatty acids. Fatty acids are lipids that are comprised of long chains of methyls, according to Stars and Seas. Methyls are forms of hydrocarbons. Plants that have cocoa butter have a lot of saturated fatty acids. They are hydrocarbons, meaning that they have an equal number of hydrogen and carbon atoms, according to Cyber Lipid. They include butyric acid, valeric acid, caprylic acid and lauric acid. Plants that have a lot of saturated fats do not have very many essential fatty acids.
Lipids found in plants play an important part in market values. Vegetable oil, olive oil, canola and avocado oil are all acquired from plants that contain these lipids. These oils are used frequently in cooking and many also have health benefits, especially olive oil and avocado oil.