What is the difference between fats and lipids

Fats, like protein and carbohydrates, are a nutrient group that supplies energy to the body. Fats are organic compounds that come in liquid or solid form. They are composed of saturated and unsaturated fatty acids. Saturated fat causes high levels of bad cholesterol, known as LDL, and can be found in animal products and vegetable oils.

Unsaturated fats help to lower bad cholesterol, but still must be consumed in moderation because of their caloric content. Unsaturated fats are found in most liquid vegetable oils. Waxes are a type of lipid that are the esthers of fatty acids.

Well-known waxes include beeswax, spermaceti and carnuba wax. In nature, wax coatings help protect the surface of some fruits and leaves from dehydration, predators and pests. The third carbon of the glycerol molecule is attached to a phosphate group.

Thereby, phospholipids are amphipathic molecules in which the diglyceride part is hydrophobic while the phosphate group is hydrophilic. Phospholipids are the main structural component of the cell membrane, and they form the phospholipid bilayer. The phospholipid molecules make the cell membrane a selectively permeable barrier.

The structure of the phospholipid bilayer is shown in figure 1. Figure 1: Phospholipid Bilayer. Steroids are a type of hydrophobic molecules mostly found as cholesterol and hormones. Cholesterol is the precursor of other types of steroids in the body. Fats refer to an oily substance that occurs in the body under the skin or around the organs. Since the degree of saturation of fatty acids is high, fats are typically solid at room temperature.

The unsaturated fat is known as oils, which are liquids at room temperature. Typically, fats have an animal origin, and oils have a plant origin. The two types of fats are the saturated fat and the trans fat. Milk products, meat, butter, and cheese are the major sources of dietary saturated fat. The consumption of saturated fat is good for the health since it increases the levels of good cholesterol or the high-density lipoprotein HDL , which lowers the risk of cardiovascular disease.

Figure 2: Food containing Fat. Trans fat is produced by the partial dehydrogenation of liquid vegetable oils. It contains a single, double bond in its structure. Due to the high degree of saturation, trans fats are also solids at room temperature.

Three molecules of water are released in the process. Fatty acids may be saturated or unsaturated. In a fatty acid chain, if there are only single bonds between neighboring carbons in the hydrocarbon chain, the fatty acid is said to be saturated. Saturated fatty acids are saturated with hydrogen since single bonds increase the number of hydrogens on each carbon. Stearic acid and palmitic acid, which are commonly found in meat, are examples of saturated fats.

When the hydrocarbon chain contains a double bond, the fatty acid is said to be unsaturated. Oleic acid is an example of an unsaturated fatty acid. Most unsaturated fats are liquid at room temperature and are called oils.

If there is only one double bond in the molecule, then it is known as a monounsaturated fat; e. If there is more than one double bond, then it is known as a polyunsaturated fat; e.

Unsaturated fats help to lower blood cholesterol levels whereas saturated fats contribute to plaque formation in the arteries. Unsaturated fats or oils are usually of plant origin and contain cis unsaturated fatty acids. Cis and trans indicate the configuration of the molecule around the double bond. If hydrogens are present in the same plane, it is referred to as a cis fat; if the hydrogen atoms are on two different planes, it is referred to as a trans fat.

Fatty Acids : Saturated fatty acids have hydrocarbon chains connected by single bonds only. Unsaturated fatty acids have one or more double bonds. Each double bond may be in a cis or trans configuration.

In the cis configuration, both hydrogens are on the same side of the hydrocarbon chain. In the trans configuration, the hydrogens are on opposite sides. A cis double bond causes a kink in the chain. In the food industry, oils are artificially hydrogenated to make them semi-solid and of a consistency desirable for many processed food products.

During this hydrogenation process, gas is bubbled through oils to solidify them, and the double bonds of the cis-conformation in the hydrocarbon chain may be converted to double bonds in the trans-conformation. Margarine, some types of peanut butter, and shortening are examples of artificially-hydrogenated trans fats. Many fast food restaurants have recently banned the use of trans fats, and food labels are required to display the trans fat content. Essential fatty acids are fatty acids required for biological processes, but not synthesized by the human body.

Consequently, they have to be supplemented through ingestion via the diet and are nutritionally very important. Omega-3 fatty acid, or alpha-linoleic acid ALA , falls into this category and is one of only two fatty acids known to be essential for humans the other being omega-6 fatty acid, or linoleic acid. These polyunsaturated fatty acids are called omega-3 because the third carbon from the end of the hydrocarbon chain is connected to its neighboring carbon by a double bond.

Salmon, trout, and tuna are good sources of omega-3 fatty acids. Research indicates that omega-3 fatty acids reduce the risk of sudden death from heart attacks, reduce triglycerides in the blood, lower blood pressure, and prevent thrombosis by inhibiting blood clotting.

They also reduce inflammation and may help reduce the risk of some cancers in animals. Omega Fatty Acids : Alpha-linolenic acid is an example of an omega-3 fatty acid. It has three cis double bonds and, as a result, a curved shape. For clarity, the carbons are not shown. Each singly bonded carbon has two hydrogens associated with it, also not shown. Waxes are nonpolar lipids that plants and animals use for protection and have many functions in society.

Waxes are a type of long chain nonpolar lipid. Natural waxes are typically esters of fatty acids and long chain alcohols. Waxes are synthesized by many animals and plants. Animal wax esters are typically derived from a variety of carboxylic acids and fatty alcohols.

The composition of a wax depends not only on the species, but also on the geographic location of the organism. The best known animal wax is beeswax, but other insects secrete waxes as well. A major component of beeswax is the ester myricyl palmitate, which bees use for constructing honeycombs. One of its main constituents is cetyl palmitate, an ester of a fatty acid and fatty alcohol. Plant waxes are derived from mixtures of long-chain hydrocarbons containing functional groups such as alkanes, fatty acids, alcohols, diols, ketones, and aldehydes.

Plants also use waxes as a protective coating to control evaporation and hydration and to prevent them from drying out. Waxes are valuable to both plants and animals because of their hydrophobic nature. This makes them water resistant, which prevents water from sticking on surfaces. Plant Waxes : Waxy coverings on some leaves are used as protective coatings.

Unlike most natural waxes, which are esters, synthetic waxes consist of long-chain hydrocarbons lacking functional groups. Paraffin wax is a type of synthetic wax derived from petroleum and refined by vacuum distillation.