Monomers & Covalent Bonds (College Board AP® Biology): Study Guide
Hydrolysis & dehydration synthesis
Polymers & monomers
Polymers play an important role in biological molecules
The term 'biological macromolecule' is often used to describe biological polymers
A polymer is made of a large number of monomers joined together
Many metabolic processes involve the breaking and making of biological macromolecules
Monomer | Polymer |
|---|---|
Monosaccharide (e.g., glucose) | Starch, glycogen, cellulose |
Amino acids | Polypeptides and proteins |
Nucleic acids | Nucleotides |
Dehydration synthesis
Many monomers join together to form a polymer
Dehydration synthesis is the process by which two molecules of monomer join together with a covalent bond
A molecule of water is given off as a byproduct
Hence the term 'dehydration'
One large molecule is produced (synthesized)
When this happens many times over, a polymer begins to form, with the production of a water molecule each time a new monomer joins the polymer
This is a common theme in the building of many different types of biological macromolecules
Examiner Tips and Tricks
Dehydration synthesis is sometimes referred to as a condensation reaction.
Hydrolysis
Hydrolysis means ‘lyze’ (to break) and ‘hydro’ (with water)
In the hydrolysis of polymers, covalent bonds are broken when water is added
Summary table of the covalent bonds formed by dehydration synthesis and broken by hydrolysis
Examiner Tips and Tricks
Remember, you don't need to remember specific molecular structures of nucleotides, amino acids and carbohydrate polymers for the AP exam. You will, however, need to recognize diagrams of generalized versions of these molecules.
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