https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/dna-and-rna-structure/v/molecular-structure-of-dna 2023-12-04T19:02:25.924542584Z Molecular structure of DNA DNA, short for deoxyribonucleic acid, consists of nucleotides forming a double helix structure. Nucleotides contain a phosphate group, deoxyribose sugar, and a nitrogenous base. The bases, adenine, thymine, cytosine, and guanine, pair up through hydrogen bonds, creating the rungs of the DNA ladder. Sal Khan video https://cdn.kastatic.org/googleusercontent/8CAJsW9lm5PD2iqAOUcaBs0SdH5kHWd9vp0hQQZSfvR0266sVqQL_LcDa7DaTO9bZfE8uC8NPZkcrCvMSBiwdedR Molecular structure of DNA DNA, short for deoxyribonucleic acid, consists of nucleotides forming a double helix structure. Nucleotides contain a phosphate group, deoxyribose sugar, and a nitrogenous base. The bases, adenine, thymine, cytosine, and guanine, pair up through hydrogen bonds, creating the rungs of the DNA ladder. https://cdn.kastatic.org/ka-youtube-converted/L677-Fl0joY.mp4/L677-Fl0joY.mp4 781 Nucleic acid (structure and role in genetic information) https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/dna-and-rna-structure/v/molecular-structure-of-rna 2023-06-22T09:32:02.370557018Z Molecular structure of RNA DNA and RNA have different sugar backbones: deoxyribose for DNA and ribose for RNA. Notably, RNA has uracil instead of thymine as a nitrogenous base. RNA plays various roles in cells, including messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and microRNA, and it is a vital part of processes such as transcription, translation, and cellular functions. Sal Khan video https://cdn.kastatic.org/googleusercontent/h1FObigLo5Ws6DQyI0rvscZJD8U2s8Ob78wh75lDvw2DSbV8myer4FbWdbzDvRKmeRTN7Wv_zWj0s6SYj0S4COM Molecular structure of RNA DNA and RNA have different sugar backbones: deoxyribose for DNA and ribose for RNA. Notably, RNA has uracil instead of thymine as a nitrogenous base. RNA plays various roles in cells, including messenger RNA (mRNA), transfer RNA (tRNA), ribosomal RNA (rRNA), and microRNA, and it is a vital part of processes such as transcription, translation, and cellular functions. https://cdn.kastatic.org/ka-youtube-converted/jUUJSOM1ihU.mp4/jUUJSOM1ihU.mp4 690 Nucleic acid (structure and role in genetic information) 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 acid (structure and role in genetic information) https://www.khanacademy.org/science/ap-biology/gene-expression-and-regulation/translation/v/rna-transcription-and-translation 2024-06-28T21:00:15.59562973Z DNA replication and RNA transcription and translation DNA serves as the molecular basis of heredity through replication, expression, and translation processes. Replication creates identical DNA strands, while transcription converts DNA into messenger RNA (mRNA). Translation then decodes mRNA into amino acids, forming proteins essential for life functions. Sal Khan video https://cdn.kastatic.org/googleusercontent/806NZEbK_c_IhZXoSWOEeXAJvPTVj0XYvpEufW6b3b6PXpDcgrStb3a6XG0yGMghOYADT_XmGhaft8p7LU9fZPg DNA replication and RNA transcription and translation DNA serves as the molecular basis of heredity through replication, expression, and translation processes. Replication creates identical DNA strands, while transcription converts DNA into messenger RNA (mRNA). Translation then decodes mRNA into amino acids, forming proteins essential for life functions. https://cdn.kastatic.org/ka-youtube-converted/6gUY5NoX1Lk.mp4/6gUY5NoX1Lk.mp4 924 Nucleic acid (structure and role in genetic information) 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/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