Local folding of the backbone into alpha helices and beta sheets stabilised by hydrogen bonds.
Alpha helices coil with hydrogen bonds between the C=O of one residue and the N-H four residues ahead; beta sheets form between adjacent strands, parallel or antiparallel. Turns and loops connect them.
Keratin is rich in alpha helices; silk fibroin is mostly beta sheets.
Remember: secondary structure involves backbone hydrogen bonds only, not the R groups.
Local folding of the backbone into alpha helices and beta sheets stabilised by hydrogen bonds.
Secondary 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 Tertiary Structure, DNA Structure, Amino Acids.
Work through the Beginner topics in Biomolecules & Biochemistry first, such as Water Properties, Carbon Chemistry, Carbohydrates, then return to Secondary Structure. Intermediate topics assume the Beginner vocabulary.
The closest topics to Secondary Structure are Tertiary Structure, DNA Structure, Amino Acids, ATP Structure and Function. Comparing them side by side is a good way to see how the ideas connect.
Read the summary and the in-depth section, then use the quick check on the interactive lesson for Secondary Structure. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
Secondary Structure: Local folding of the backbone into alpha helices and beta sheets stabilised by hydrogen bonds. Tertiary Structure: The overall three-dimensional shape of one polypeptide, held by side-chain interactions and disulfide bridges. Read both side by side and note what each one explains.
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 Tertiary Structure and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.
The overall three-dimensional shape of one polypeptide, held by side-chain interactions and disulfide bridges.
⚗️ Biomolecules & BiochemistryTwo antiparallel strands of nucleotides wound into a double helix, held together by base pairing.
⚗️ Biomolecules & BiochemistryTwenty building blocks, each with an amino group, a carboxyl group and a variable side chain.
⚗️ Biomolecules & BiochemistryAdenosine triphosphate stores energy in its phosphate bonds and acts as the universal energy currency of cells.
⚗️ Biomolecules & Biochemistry