People need lipids because they are used for energy, generating ATP in cellular respiration, building storage triglycerides and phospholipids for membranes and manufacturing certain hormones, according to Dr. Dawn Tamarkin from Springfield Technical Community College. Lipids are essential fats, and there are different types of lipids including triglycerides, phospholipids and steroids.
Triglycerides are primarily used as energy reserves, explains Tamarkin. The body breaks down triglycerides and uses the products for cellular respiration. Triglycerides are also stored as fat after the digestive system breaks them down into glycerol and fatty acids, which are absorbed for the production of chylomicrons. Once the chylomicrons are created, they diffuse into the lacteal and soon enter the blood. Fatty acids are taken out of the chylomicrons and delivered into tissues that require them as the chylomicrons travel through the blood.
The body uses fatty acids for cellular respiration by breaking them down into two-carbon molecules. These molecules then enter the cellular respiration process to produce ATP. Another use of fatty acids is for building storage triglycerides, or fat for later use, and phospholipids for the body’s membranes. Cholesterol plays a key role in producing particular hormones and making bile salts. It also makes up the lipid bilayer of cells, notes Tamarkin.