A diagram shows the three separate components of a nucleotide and how they are combined to form a complete molecule. A nitrogenous base is represented as a purple hexagon. A sugar is represented as a grey pentagon. A phosphate group is represented as a light brown circle. A cut-away from the generic nitrogen base shows the chemical structure of the three types of pyrimidine bases (cytosine, thymine, and uracil) and the two types of purine bases (adenine and guanine).
This Modern Genetics PowerPoint Presentation has 20 slides on the following topics: Chemical Basis for Genetics, Nucleotides, Nitrogenous Bases of DNA, DNA Structure, DNA Replication, RNA - Ribonucleic Acid, Mutations, Human Genetic Diseases, Genetic Engineering, How to Clone a Sheep. $3.50
Building the model helped me understand the structure of DNA because I could "see" what nitrogen bases bonded (Guanine with Cytosine and Thymine with Adenine connected by a hydrogen bond) and understood that a nucleotide consisted of phosphate, deoxyribose sugar, and a nitrogen base.
Basic Components of Nucleic Acids - Nitrogenous bases, Ribose and Phosphate group. The bases are Purines (A,G) and Pyrimidine (C,T,U). Ribose, Phosphate. http://www.biochemden.com/basic-components-nucleic-acids-purines-pyrimidines
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
The structure of DNA is similar to a ladder. It has a chemical phosphate and sugar backbone, which make up the sides of the ladder. (Deoxyribose is the sugar found in the backbone of DNA.) The two sides of this sugar-phosphate backbone are four nitrogenous bases: adenine (A), thymine (T), cytosine (C), and guanine (G). (A grouping like this of a phosphate, a sugar, and a base makes up a subunit of DNA which is known as a nucleotide.
Double-stranded DNA consists of two polynucleotide chains whose nitrogenous bases are connected by hydrogen bonds. Within this arrangement, each strand mirrors the other as a result of the anti-parallel orientation of the sugar-phosphate backbones, as well as the complementary nature of the A-T and C-G base pairing.