1. LipidsA lipid is a group of natural molecules. This group includes fats, waxes, steroids, fat-soluble vitamins (A, D, E and K), phospholipids, etc. They are broadly defined as small hydrophobic or amphiphilic molecules. Amphiphilic molecules form structures such as vesicles, liposomes and membranes in an aqueous environment. They are insoluble in water, but soluble in alcohol. (Human biology)Lipids contain carbon, hydrogen, and oxygen, but they contain much less oxygen than carbohydrates. They have high melting points. (Human biology) Saturated acids have a higher melting point than unsaturated acids. Lipids can be extracted from plants and animals using solvents such as ether, chloroform and acetone. (Chemistry: principles and properties)Lipids store energy in fats and act as structural components of cell membranes. They constitute an essential nutrient for the human body. Triglycerides (fats and oils) give the body the energy it needs to function. They serve as components of hormones and vitamins. They are used in the cosmetics and food industries as well as in the field of nanotechnology. In health care, doctors use lipid tests and profiles to measure the amount of cholesterol and triglycerides in a person's blood.2. FatsFat plays an important role in your body, but too much of it can be very unhealthy. Lipids create a fat storage system that releases energy when the body needs it. Fat also insulates the body and keeps it warm. The human body must maintain a certain temperature and fat helps maintain that temperature. (A Life Science Lexicon) Fats also serve as protection for the organs inside your body. Insulating the fat around your internal organs protects them from any potential injury or damage....... middle of paper ......e more likely to be fluid. Saturated fats have a higher melting point and are more likely to be solid at room temperature. (Human biology)Triglycerides are the main ingredients of vegetable oil. In this case, they are generally more unsaturated. There are also animal fats. They are generally more saturated in animal fats. Triglycerides are also a major component of human skin oils. In the human body, high levels of triglycerides in the blood have been associated with atherosclerosis. It has also been linked to the risk of heart disease and stroke. However, the relative negative impact of high triglyceride levels versus that of good cholesterol versus bad cholesterol is still unknown. The risk can be explained mainly by a strong inverse relationship between the level of triglycerides and the level of bad cholesterol. (A glossary of life sciences)