Summary
Fats formed from glycerol joined to three fatty acids, the main long-term energy store in animals.
In depth
A triglyceride is glycerol with three fatty acid chains attached by ester bonds made in condensation reactions. Fatty acids can be saturated or unsaturated, and the mixture determines whether the fat is solid or liquid at room temperature.
They are stored in adipose tissue, which also cushions organs and insulates the body. Metabolic water is a by-product of fat oxidation, helping desert animals.
The three ester bonds are made in condensation reactions, giving three molecules of water, and they are broken by lipases in hydrolysis. Fat is stored in adipocytes in droplets that can fill most of the cell, and brown fat has many mitochondria that burn fat to make heat rather than ATP.
Fatty acid names show structure: oleic acid is 18:1 with one double bond, and omega-3 fatty acids have the first double bond three carbons from the methyl end, as in fish oils. Soaps are made by hydrolysing triglycerides with alkali (saponification).
Example: hibernating bears live for months on stored triglycerides and obtain water from their oxidation.
Frequently asked questions
What is Triglycerides?
Fats formed from glycerol joined to three fatty acids, the main long-term energy store in animals.
Which area of biology covers Triglycerides, and how advanced is it?
Triglycerides is one of the 51 topics in Biomolecules & Biochemistry. It is rated Beginner, so it suits learners who are starting out in biology. Related topics in this area include Lipids, Water Properties, Saturated and Unsaturated Fats.
Can you give an example of Triglycerides?
A camel's hump stores fat, not water.
What should I learn before Triglycerides?
Triglycerides is a Beginner topic, so no earlier topic is required. Other Beginner topics in Biomolecules & Biochemistry that pair well with it include Water Properties, Carbon Chemistry, Carbohydrates.
What topics are related to Triglycerides?
The closest topics to Triglycerides are Lipids, Water Properties, Saturated and Unsaturated Fats, Macromolecules. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Triglycerides?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Triglycerides. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
How is Triglycerides different from Lipids?
Triglycerides: Fats formed from glycerol joined to three fatty acids, the main long-term energy store in animals. Lipids: Hydrophobic molecules including fats, oils, waxes and steroids used for energy storage, insulation and membranes. Read both side by side and note what each one explains.
How should I study Triglycerides step by step?
First, read the summary and write the definition in your own words. Second, read the in-depth section and note any example. Third, compare it with Lipids and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.