1. Triglycerides The major lipids of the body (triglycerides, cholesterol, phospholipids and glycolipids) play a variety of biologic roles. They serve as: Source of fuel. Important component of cell membranes and many cells structures.

2. They provide stability to the cell membrane and allow for transmembrane transport. They are transported through the blood stream in the form of lipoprotein. Fatty Acids: The lipid building blocks. Fatty acids are composed of a chain of methylene groups with a Carboxyl functional group at one end.

3. Fatty acid Glycerol or Glycerin Glycerol is a trihydric alcohol (containing three - OH hydroxyl groups) that can combine with up to three fatty acids to form monoglycerides, diglycerides, and triglycerides

4. Triglycerides A triglyceride consists of a glycerol and three fatty acids. It is the major type of lipid used for energy storage and it is found in droplets within the cytoplasm. It is non-polar and relatively insoluble.

5. Triglycerides structure:

6. The source of TG in the body can be either dietary or synthesized in liver and other tissues. TG molecules allow the body to compactly store long carbon chains(FA) for energy that can be used during fasting states between meals. Normal values: 40 – 160 mg /dl.

7. Usually, serum triglyceride concentration is requested either in combination with total cholesterol or as part of lipid panel examination (total cholesterol, triglycerides, HDL, LDL and VLDL determination) to estimate the degree of risk for hyperlipoproteinemia, coronary artery disease (CAD), heart disease and stroke.

8. Clinical significance: Increase in serum TG are relatively non specific. in heart diseases, liver and renal diseases. as in hyperthyroidism.

9. Method for determination: Quantitative enzymatic method: Principle: TG +H2O LPL glycerol + free FA. Glycerol+ATP glycerol kinase G3P+ ADP G3P+O₂ GPO DAP+ H₂O₂ H₂O₂+4AAP+4-Chlorophenol POD Quinoneimine+2H2O