Materials that are insolubility, or unable to dissolve in water are called lipids. Oils, fats and other fat like substances are called lipids and they are used in the body to help store energy and to help build the cells.

Lipid also help to carry fat-soluble vitamins throughout the body, where they are needed.

Some hormones found in the body are lipids and the cell membrane is made up mostly of lipids.

Lipids are one of the four major groups of organic molecules and they contain more hydrogen atoms than oxygen atoms.

Fatty Acids

The simplest lipid is the fatty acid. A fatty acid is made up of carbon and oxygen atoms and is connected to a long chain of carbon and hydrogen atoms.

Saturated fatty acids are saturated because they cannot hold any more hydrogen atoms. Saturated fats are fasts that are solid at room temperature.

Saturated fats are found in foods such as red meat, animal fat foods, cheeses, fast foods, bakery items and butter.

These types of fats are called bad fats because they can cause a person to have high cholesterol and can clog the arteries, making chances of heart disease higher. Hydronated oils are considered saturated.

Unsaturated fatty acids can form hydrogen bonds. Unsaturated fats are fats that are liquid when they are at the temperature of a room.

Unsaturated fats are sometimes called oils. These fats come from foods such as fish, vegetable and nuts. Unsaturated fats are considered good fats because they are healthier than other fats.


Cholesterol is another lipid that our body uses to make bile and Vitamin D. Cholesterol also is important for hormones and small amounts of it are found in the cell membrane.

The liver makes cholesterol if it is not found in the foods that we eat. Cholesterol is an important nutrient, but too much of it can cause heart disease.

Function of Fats

Fats are made of glycerol and three fatty acid molecules. Fat is made up of carbon, hydrogen and oxygen and it is stored in the body to give the body energy.

People cannot live without fat and fat is important because it helps the body in many different ways. One function of fat is that it helps to prevent water loss.

As humans, we have wax in our ears to protect our eardrums, this is made up of fat. Fat is used for protection and helps to regulate our body temperatures.

Steroids, another type of lipid, help our bodies. Our bodies need steroids such as cortisol and cholesterol to live, and steroids can help people that have sickness in their bodies.

Phospholipids, another type of lipid, is important to our bodies because our cell membranes contain phospholipids.

Facts About Fats and Lipids

  • Fats can help our bodies to dissolve vitamins such as Vitamin A and Vitamin D.
  • Waxes that are made from lipids, are found in items that we use every day such as gum, candles, nail polish and more.
  • When a compound is not water-soluble, it is called hydrophobic.
  • Cortisol helps our body to have energy and fight off diseases. Cortisol is a steroid that is made from lipids.
  • Cholesterol helps to make hormones such as testosterone and estrogen.
  • 20-30 percent of our fat is from foods that we eat.
  • Fat that we eat can be unhealthy, clogging our arteries.

What Did You Learn?

  • What is insolubility? Insolubility means that something cannot be absorbed in water.
  • What type of fat is bad for a person to eat a lot of? Too much saturated fat can be unhealthy for a person and can clog arteries and cause heart disease.
  • What is the lipid, wax, used for? Wax helps to protect our bodies, such as wax in our ears help to keep things out of the eardrum.
  • What are the three elements that make up a lipid? The three elements that make up lipids are carbon, hydrogen and oxygen.
  • What do lipids produce that help our bodies to fight off diseases? Lipids produce cortisol and other hormones that help to regulate our bodies and fight off diseases.