4.6 Lesson 6: Macromolecules, Synthesis, and Hydrolysis
- Macromolecules are composed of long complex chains of molecules (polymers) made up of simpler, smaller subunits (monomers). There are four classes of macromolecules that constitute all living matter: carbohydrates, lipids, proteins, and nucleic acids. While they have different structures and functions, they are all joined together in a process known as dehydration synthesis, in which a covalent bond is formed between two monomers by releasing a water molecule. Also, they can all be broken down by a process called hydrolysis where a water molecule is used up.
- The carbohydrate polymer is made from monomers called monosaccharides.
- The lipid polymer is made from monomers called glycerol and fatty acids.
- The protein polymer is made from monomers called amino acids.
- The nucleic acid polymer is made from monomers called nucleotides.
- Dehydration synthesis and hydrolysis are processes that build up or break down macromolecules.
- Dehydration means to take water out and synthesis means to build up. Therefore dehydration synthesis means the building up of polymers from monomers, while taking water out.
- ex. in carbohydrates, an H ion from one monosaccharide and an OH ion from another are taken out, they form water. The two monosaccharides are then joined together by a bond called a glycosidic bond.
- Hydrolysis is the reverse of dehydration synthesis. It is a chemical process in which a molecule is cleaved into two parts by the addition of water. One fragment of the parent molecule gains a hydrogen ion (H+) from the additional water molecule. The other group collects the remaining hydroxyl group (OH − ).
