Triglycerides

Vicki Ng Block C

=__**Triglycerides (also known as** triacylglycerols)____**:**__=

__**Name and structure:**__
Triglycerides are neutral lipid molecules created through the esterification of three fatty acids to a single glycerol molecule. One way to visualize these triglycerides is to think of a capital "E." Forming the vertical backbone of this E is a molecule known as glycerol (a trifunctional alcohol). Attached to this glycerol backbone and forming the horizontal elements of the E are three long chains composed of carbon, hydrogen, and oxygen. These are called fatty acids. The three fatty acids can be all different, all the same, or only two the same, they can be saturated or unsaturated fatty acids. Triglycerides are called "fats" or "butters" when they are solid and they are called "oils" when they are liquid. Triglycerides are also "hydrophobic", or in other words, they are insoluble in water.





__**How are triglycerides made?**__ Our livers can change any source of excess calories into triglycerides. Triglycerides are made of:
 * Glycerol (A trifunctional alcohol and is a common ingredient used in making such things as soap, pharmaceuticals and cosmetics)


 * Three fatty acids (A carboxylic acid often with a long chain and can be saturated or unsaturated)



Each hydroxyl group in glycerol connects to a long chain molecule called a fatty acid, resulting in a three-tailed molecule which is a triglyceride. The three fatty acids may or may not be identical. In fact, three different fatty acids may be present.



Both of the glycerol and fatty acid chains have -OH bonds, which together contribute 2 hydrogen atoms and 1 oxygen atom to form water. The resulting compound is also called a triglyceride, or a neutral fat.

__**How do triglycerides affect us?**__ Triglycerides are a type of fat that circulates in our blood. When we eat, our bodies convert any calories it doesn't need to use right away into triglycerides. The triglycerides are stored in our fat cells. Later, hormones release triglycerides for energy for our bodies. Triglycerides are the most abundant form of stored potential fuel in the human body. If you regularly eat more calories than you burn, you may have high triglycerides (hypertriglyceridemia). High triglycerides may contribute to hardening of the arteries or thickening of the artery walls — which increases the risk of stroke, heart attack and heart disease.

Triglycerides are also used to make biodiesel. Biodiesel is the name of a clean burning alternative fuel, produced from renewable resources. Biodiesel is used by diesel cars and greatly reduces our carbon footprint. Most manufacturing facilities produce industrial biodiesel through a process called transesterification. The transesterification process is the reaction of a triglyceride (fat/oil) with an alcohol, usually methanol (CH3OH) or ethanol (CH3CH2OH) in the presence of a catalyst such as potassium hydroxide (KOH) or sodium hydroxide (NaOH) to form esters and glycerol. The esters that remain are then call biodiesel.

__**Interesting facts:**__
- When we eat food, the triglyceride structure is broken down and then reformed in our bodies.
 * How do they form in our bodies? -- Your body transforms carbohydrates you eat into glucose to be used for energy by your cells. Once the cells have what they need, the excess glucose is sent back to your liver and converted to glycogen. Glycogen can then be stored in your muscles. Once you've reached your capacity of glycogen, excess glycogen is sent back to your liver again, where it becomes triglyceride's, which are stored as fat.

- A normal human's fat content allows for food starvation of approximately three months. Our sugar reserves, on the other hand, would last around one day.
 * How? -- Each pound of body fat (or triglycerides) contains about 3500 calories, enough energy for the average person for about a day and half. During a survival situation when there is not enough food to eat, a few extra pounds can come in handy.

__**Sources:**__
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