https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/dna-and-rna-structure/v/introduction-to-nucleic-acids-and-nucleotides 2023-06-06T10:35:22.92767095Z Introduction to nucleic acids and nucleotides Nucleic acids, crucial macromolecules for life, were first discovered in cell nuclei and exhibit acidic properties. DNA and RNA, composed of nucleotide building blocks, store hereditary information. These polymers have a backbone of alternating ribose and phosphate groups, with nitrogenous bases forming ladder rungs. The sequence of nucleotides encodes genetic information, making nucleic acids fundamental to life. Sal Khan video https://cdn.kastatic.org/ka_thumbnails_cache/6074048f-6b8d-4794-b02a-7bb056d6dff4_1280_720_base.png Introduction to nucleic acids and nucleotides Nucleic acids, crucial macromolecules for life, were first discovered in cell nuclei and exhibit acidic properties. DNA and RNA, composed of nucleotide building blocks, store hereditary information. These polymers have a backbone of alternating ribose and phosphate groups, with nitrogenous bases forming ladder rungs. The sequence of nucleotides encodes genetic information, making nucleic acids fundamental to life. https://cdn.kastatic.org/ka-youtube-converted/hI4v7v8AdfI.mp4/hI4v7v8AdfI.mp4 355 Nucleic acids https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/dna-and-rna-structure/v/dna-deoxyribonucleic-acid 2023-06-06T10:35:22.92767095Z DNA DNA, or deoxyribonucleic acid, is the molecular basis for inheritance, discovered in the mid-1800s and understood in 1953 with the double helix structure. Composed of a sugar-phosphate backbone and base pairs (adenine-thymine, guanine-cytosine), DNA stores genetic information, replicates, and expresses traits. The human genome contains 6 billion base pairs across 46 chromosomes, making it a compact and efficient information storage system. Sal Khan video https://cdn.kastatic.org/googleusercontent/N-FD1seHs-vdXACc6Ug4MuC44TkW3_s9SQcxTbnTpvAsX9wVNZXctud872V8KvhGq_fRRDQjDIVNX55fJrm1WiMGGw DNA DNA, or deoxyribonucleic acid, is the molecular basis for inheritance, discovered in the mid-1800s and understood in 1953 with the double helix structure. Composed of a sugar-phosphate backbone and base pairs (adenine-thymine, guanine-cytosine), DNA stores genetic information, replicates, and expresses traits. The human genome contains 6 billion base pairs across 46 chromosomes, making it a compact and efficient information storage system. https://cdn.kastatic.org/ka-youtube-converted/AmOO4j0E408.mp4/AmOO4j0E408.mp4 782 Nucleic acids https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/dna-and-rna-structure/a/nucleic-acids 2026-03-17T04:40:31.334379942Z Nucleic acids DNA and RNA structure and function. Nucleotides and polynucleotides. mRNA, rRNA, tRNA, miRNA, and siRNA. article https://www.khanacademy.org/science/revision-term-1-ka-biology-grade-11/x1474e0ca4285b2f5:week-3/x1474e0ca4285b2f5:biomolecules/e/dna-structure 2026-04-08T00:36:09.500768563Z DNA structure Questions to practice DNA structure Moumita exercise https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/dna-and-rna-structure/e/dna-and-rna-structure 2025-11-24T21:00:40.80360556Z DNA and RNA structure Test your knowledge of DNA and RNA structure! Megan Cohn exercise