Summary
Large polymers formed by condensation reactions and broken down by hydrolysis, including carbohydrates, proteins and nucleic acids.
In depth
Four classes dominate: carbohydrates, lipids (not true polymers), proteins and nucleic acids. Polymers are built from monomers by condensation reactions that need energy and enzymes. Cells continually build and recycle them.
Different polymers use few monomers in an enormous number of arrangements, which is the source of molecular diversity.
Key idea: structure determines function from the monomer up to the whole polymer.
Polymer chains are directional, and their order encodes information (DNA, proteins) or function (polysaccharide branching). Size matters: a typical protein has 300 amino acids, a polysaccharide thousands of sugars and a chromosome millions of nucleotides.
Cells make them with energy-requiring anabolic reactions and recycle them by catabolic ones. Their precursors (amino acids, sugars, nucleotides) are made from small molecules or taken in. Monomers can often be assembled by templates (DNA to RNA to protein) or by enzymes alone (carbohydrates, lipids).
Remember: lipids are called macromolecules for convenience; they assemble through weak forces and are not covalent polymers of repeating units.
Frequently asked questions
What is Macromolecules?
Large polymers formed by condensation reactions and broken down by hydrolysis, including carbohydrates, proteins and nucleic acids.
Which area of biology covers Macromolecules, and how advanced is it?
Macromolecules 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 Carbon Chemistry, Condensation and Hydrolysis, Proteins.
What should I learn before Macromolecules?
Macromolecules 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 Macromolecules?
The closest topics to Macromolecules are Carbon Chemistry, Condensation and Hydrolysis, Proteins, Triglycerides. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Macromolecules?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Macromolecules. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
How is Macromolecules different from Carbon Chemistry?
Macromolecules: Large polymers formed by condensation reactions and broken down by hydrolysis, including carbohydrates, proteins and nucleic acids. Carbon Chemistry: Carbon forms four covalent bonds, allowing chains, rings and the huge variety of organic molecules in living things. Read both side by side and note what each one explains.
How should I study Macromolecules 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 Carbon Chemistry and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.