What Are Lipids and Lipoproteins?
Previously published on Answers.com.
Beyond the Total, LDL and HDL cholesterol targets, there are a lot of scientific terms used to explain cholesterol. Lipids and lipoproteins are frequently referred to in cholesterol articles, though often there’s not a description of just what these are and what they do.
What Is A Lipid?
According to dictionary.com, a lipid is an organic compound that is, “greasy to the touch, insoluble in water, and soluble in alcohol and ether: lipids comprise the fats and other esters with analogous properties and constitute, with proteins and carbohydrates, the chief structural components of living cells.” So, lipids are molecules that don’t dissolve in water, and act as cell ‘building blocks.’
What Are The Kinds Of Lipids?
There are many kinds of lipids. The most familiar types of lipids are triglycerides (a fatty acid) and cholesterol (a waxy, fatty lipid).
Is A Lipid A Fat?
Although some use the term ‘lipid’ interchangeably with the term ‘fat,’ in fact, lipids and fats are not exactly synonymous. Rather, fats are a kind of lipid, specifically referred to as triglycerides. Triglycerides help move fat and sugar from the liver. Usually a cholesterol ‘lipid panel’ test measures triglycerides (in addition to total cholesterol, HDL, and LDL cholesterol) because high triglycerides are correlated with risk of heart disease.
What Is A Lipoprotein?
Lipoproteins are structures that contain both lipids and proteins. When a lipid (like the fat triglyceride) attaches to a protein, that structure is called a lipoprotein. The function of a lipoprotein is to carry the lipid around the body through the blood. Examples of lipoproteins include high-density (HDL) and low-density (LDL), which enable lipids like cholesterol to be carried to the liver.
Lipids are molecules that don’t dissolve in water; common and important lipids include triglycerides and cholesterol. A lipoprotein is a structure made up of a lipid and a protein. The job of lipoproteins is to carry the non-soluble lipids (like cholesterol and triglycerides) through the blood.
Did You Know?
When you have your cholesterol checked, the HDL and LDL readings are actually measurements of the lipoproteins carrying the cholesterol, not the cholesterol itself.