Biological Macromolecules Explorer
Pick one of the four classes of biological macromolecules to see its building block, polymer, elements, functions, and common examples. Then set how many monomers to link and watch dehydration synthesis release water, or run hydrolysis in reverse to break a polymer apart.
Carbohydrate
Building block
Polymer
Elements
Examples
Main functions
- Short-term energy supply
- Energy storage (starch in plants, glycogen in animals)
- Structural support (cellulose in plant cell walls)
Dehydration synthesis and hydrolysis
Monomers join by losing water (dehydration synthesis). Adding water breaks the bonds apart again (hydrolysis).
4
Monomers
3
Bonds formed/broken
3
Water released
Reference Guide
The four classes of biological macromolecules, how they are built, and the chemistry that links and breaks them.
The four classes compared
| Class | Building block | Polymer | Elements | Examples |
|---|---|---|---|---|
| Carbohydrate | Monosaccharide (glucose) | Polysaccharide | C, H, O | Starch, cellulose, glycogen |
| Lipid | Glycerol and fatty acids | Triglyceride (not a true polymer) | C, H, O | Fats, oils, phospholipids, steroids |
| Protein | Amino acid | Polypeptide | C, H, O, N, S | Enzymes, antibodies, hemoglobin, keratin |
| Nucleic acid | Nucleotide | DNA, RNA | C, H, O, N, P | DNA, RNA |
Monomers and polymers
A monomer is a single small building block. A polymer is a long chain of many monomers joined together. Glucose monomers link into the polysaccharide starch, amino acid monomers link into a polypeptide, and nucleotide monomers link into DNA and RNA.
Dehydration synthesis vs hydrolysis
In dehydration synthesis, two monomers join and one water molecule leaves at each new bond, so linking n monomers releases n minus 1 water molecules. Hydrolysis is the reverse. Adding water at each bond splits the chain back into separate units.
Why lipids are not true polymers
A polymer is built from one repeating monomer. A triglyceride is assembled from one glycerol and three fatty acids, which are different kinds of molecules and do not repeat. The 3 ester bonds still form by dehydration synthesis and release 3 water molecules, but the result is not a true polymer.
Elements and functions
All four classes contain carbon, hydrogen, and oxygen. Proteins add nitrogen and sulfur, and nucleic acids add nitrogen and phosphorus. Carbohydrates supply quick energy, lipids store energy long term and build membranes, proteins act as enzymes and structure, and nucleic acids store and transmit genetic information.
