Summary
The linear order of amino acids in a polypeptide, which determines all higher levels of folding.
In depth
The sequence is determined by the gene. Even a single substitution can matter, as in the glutamic acid to valine change in sickle cell haemoglobin. Frederick Sanger first sequenced insulin in the 1950s, showing proteins have defined sequences.
Anfinsen showed that the primary structure carries all the information for folding.
Key idea: gene sequence leads to amino acid sequence, which leads to shape and function.
Frequently asked questions
What is Primary Structure?
The linear order of amino acids in a polypeptide, which determines all higher levels of folding.
Which area of biology covers Primary Structure, and how advanced is it?
Primary Structure is one of the 51 topics in Biomolecules & Biochemistry. It is rated Intermediate, so it suits learners who already know the core vocabulary. Related topics in this area include Proteins, Carbon Chemistry, Macromolecules.
What should I learn before Primary Structure?
Work through the Beginner topics in Biomolecules & Biochemistry first, such as Water Properties, Carbon Chemistry, Carbohydrates, then return to Primary Structure. Intermediate topics assume the Beginner vocabulary.
What topics are related to Primary Structure?
The closest topics to Primary Structure are Proteins, Carbon Chemistry, Macromolecules, Quaternary Structure. Comparing them side by side is a good way to see how the ideas connect.
How can I check that I understand Primary Structure?
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Primary Structure. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
How is Primary Structure different from Proteins?
Primary Structure: The linear order of amino acids in a polypeptide, which determines all higher levels of folding. Proteins: Polymers of amino acids that act as enzymes, structural parts, transporters, hormones and antibodies. Read both side by side and note what each one explains.
How should I study Primary Structure 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 Proteins and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.