Deoxyribonucleic acid (DNA) is the hereditary matter in cells that makes up the repository for genes. DNA's structure consists of sugar, phosphate groups,and nitrogenous bases in its nucleotides. These bases are cytosine, thymine, adenine, and guanine. Cytosine and thymine are classified as pyrimidines that have a single ring. Adenine and guanine are classified as purines that have a double rings. Adenine base pairs with thymine (uracil only in RNA), and cytosine base pairs with guanine.
Complementary base pairs: purine-pyrimidinepairs; sugar-phosphate backbone; 2 DNA strands wound around one another to produce a double helix; stabilized in part by hydrogen bonds between nitrogenous bases on either strand; due to the geometry of the bases & amount of space available in helix, H bonds only form when A and T w/ 2 bonds or G and C w/ 3 bonds line up on opposite strands
Drawing this picture helped me as a visual learner to learn the structure of DNA. By drawing a DNA strand I learned that the backbone of DNA is a chain of sugar and phosphate. Linked to the sugar of the chain is one nitrogen base. The nitrogen bases are thymine, guanine, cytocine, and adenine. This chain of sugars phosphates and nitrogen bases are connected to another chain by a hydrogen bond.
3 Main differences between DNA & RNA: RNA uses the sugar Ribose while DNA uses Deoxyribose. RNA is single stranded while DNA is double stranded. RNA uses the nitrogenous base Uracil whereas DNA uses the nitrogenous base Thymine.
This DNA is a teaching model; It demonstrates different structural units of DNA: Phosphorus, Oxygen, Deoxyribose, group, 4 types of nitrogenous bases and bonding molecules of hydrogen. Each unit is shape and color coded.