How does dehydration synthesis work

Dehydration synthesis in lipids

In the synthesis of dehydration, smaller building blocks are made into a larger molecule by removing two hydrogen atoms and one oxygen atom - the chemical components of water. Lipids are fats; The most common lipids in the body include triglycerides (diet and storage fats) and phospholipids, which form cell membranes. You produce your large biological lipids through dehydration synthesis.

Cell membranes are made up of lipids that are made through dehydration synthesis. (Image: Shing Lok Che / iStock / Getty Images)

Dehydration synthesis

Dehydration reactions are a class of chemical transformations, particularly in biochemistry. There are a variety of metabolic processes in your body that turn smaller precursor molecules into larger molecules, many of which occur through synthesis of dehydration. During a dehydration synthesis, two smaller molecules together lose two hydrogen atoms and one oxygen atom. The smaller molecules form new bonds, explain Drs. Reginald Garrett and Charles Grisham in their book "Biochemistry".


Triglycerides are an important class of lipids, or fats. These are the types of lipids that you ingest when you ingest fat in your diet. They are also the lipids that you store in adipose or adipose tissue. Triglycerides consist of a chemical backbone made up of a glycerol molecule that is similar in structure to alcohol. The triglyceride also contains three long chains of carbon and hydrogen, each of which has two oxygen atoms on one end. These long molecules are called fatty acids. When a plant or animal produces triglyceride, it binds each of the fatty acids to the glycerol backbone through dehydration synthesis.


Another important class of lipids in your body are the phospholipids. These are the main components of cell membranes, explains Dr. Lauralee Sherwood in her book "Human Physiology". Like triglycerides, they consist of a glycerol backbone. They also contain two fatty acids and a small molecule called phosphate. In the production of a phospholipid, the fatty acids and the phosphate group are attached to the glycerol backbone through dehydration synthesis.


The reverse of the dehydration reaction is called hydrolysis, which literally means "splitting with water". When you break down triglycerides from food, you need to separate two of the fatty acids from the glycerol backbone. This requires water because the hydrolysis reaction introduces two hydrogen atoms and one oxygen atom - essentially a water molecule - through the bond between glycerol and each fatty acid in a triglyceride molecule. The reliance of digestion on hydrolysis is one of the reasons your digestive tract needs water to function.