Two antiparallel strands of nucleotides wound into a double helix, held together by base pairing.
Two antiparallel polynucleotide strands form a right-handed double helix about 2 nm wide with 10 base pairs per turn. A pairs with T through two hydrogen bonds and G pairs with C through three, so GC-rich DNA is more heat stable.
Watson and Crick built the model in 1953 using Rosalind Franklin's X-ray diffraction images and Chargaff's rules (A = T, G = C).
Two antiparallel strands of nucleotides wound into a double helix, held together by base pairing.
DNA 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 Secondary Structure, Nucleic Acids, Quaternary Structure.
The complementary strands explain how DNA is copied accurately.
Work through the Beginner topics in Biomolecules & Biochemistry first, such as Water Properties, Carbon Chemistry, Carbohydrates, then return to DNA Structure. Intermediate topics assume the Beginner vocabulary.
The closest topics to DNA Structure are Secondary Structure, Nucleic Acids, Quaternary Structure, Tertiary Structure. 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 DNA Structure. To practise the whole of Biomolecules & Biochemistry, use the Biomolecules & Biochemistry quiz.
DNA Structure: Two antiparallel strands of nucleotides wound into a double helix, held together by base pairing. Secondary Structure: Local folding of the backbone into alpha helices and beta sheets stabilised by hydrogen bonds. 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 Secondary Structure and explain the difference aloud. Finally, take the Biomolecules & Biochemistry quiz and come back to this page for any question you miss.
Local folding of the backbone into alpha helices and beta sheets stabilised by hydrogen bonds.
⚗️ Biomolecules & BiochemistryDNA and RNA, polymers of nucleotides that store and transmit genetic information.
⚗️ Biomolecules & BiochemistryThe arrangement of multiple polypeptide subunits into one functional protein, such as haemoglobin.
⚗️ Biomolecules & BiochemistryThe overall three-dimensional shape of one polypeptide, held by side-chain interactions and disulfide bridges.
⚗️ Biomolecules & Biochemistry