Model of a Nucleotide

Introduction

Nucleotides consist of three parts --- a pentose sugar, a nitrogen-containing base, and a phosphate group. A pentose sugar is a five-sided sugar. There are 2 kinds of pentose sugars --- deoxyribose and ribose. Deoxyribose has a hydrogen atom attached to its #2 carbon atom (designated 2'), and ribose has a hydroxyl group atom there. Deoxyribose-containing nucleotides are the monomers of DNA, while Ribose-containing nucleotides are the monomers of RNA.

A nitrogen-containing ring structure is called a base. The base is attached to the 1' carbon atom of the pentose. In DNA, four different bases are found --- two purines, called adenine (A) and guanine (G) and two pyrimidines, called thymine (T) and cytosine (C). RNA contains The same purines, adenine (A) and guanine (G).  RNA also uses the pyrimidine cytosine (C), but instead of thymine, it uses the pyrimidine uracil (U).

The Purines The Pyrimidines

The combination of a base and a pentose is called a nucleoside.  A phosphate group is attached to the 5' carbon of the pentose sugar.

Objective

Students will construct a 3-dimensional model of a single nucleotide, the monomer of which nucleic acids are composed.

Materials

Various materials may be used for the atoms that make up a nucleotide such as styrofoam balls, plastic coke bottle caps, beads, etc. Bonds between atoms may be made from toothpicks, plastic stirring sticks, popsicle sticks, etc. Single & double bonds must be represented by the correct number of "sticks". The atoms and bonds may NOT be made of any food item. Your model should be glued together to make the model rigid for hanging. Attach string and a label with the nucleotide's name to your model. Models must be sturdy, light weight, and small enough to hang from the ceiling.

Color Code for atoms:

CARBON -

BLACK

HYDROGEN -

YELLOW

OXYGEN -

RED

NITROGEN -

BLUE

Structural Formulas of Nucleotides:

Uracil Nucleotide (Ribose ) & Thymine Nucleotide (Deoxyribose)

Adenine Nucleotide (Deoxyribose)

Cytosine Nucleotide (Deoxyribose)
Guanine Nucleotide (Deoxyribose)
 

 

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