Using the internet to help you find out the following:

1. What is a DNA nucleotide?a. Any group of molecules that when linked together form the building blocks of

DNAb. A nucleotide is a sub-unit of a DNA moleculec. It consists of a Phosphate covalently bonded to De-oxy Ribose 5 carbon Sugar

that in turn is connected to one of the 4 nitrogen bases. Nucleotides covalently bond together to form a single DNA strand. 2 DNA strands join together by hydrogen bonds between nitrogen bases to form a DNA molecule.

2. Using the image library below draw the structure of a single DNA nucleotide in terms of sugar (deoxyribose), base and phosphate.

3. What are the names of the four bases in DNA?a. Adenine, Thymine, Cytosine, Guanine

4. Outline how DNA nucleotides are linked together by covalent bonds into a single strand by using the images below to make a single strand consisting of 4 nucleotides with all 4 different nitrogenous bases. Label which are covalent bonds and where hydrogen bonds might form.

Base

Deoxyribose Sugar

Phosphate Covalent bond

Guanine

Adenine

Thymine

Cytosine

5. Which Nitrogen bases pair with which others?a. Adenine and Thymine, Cytosine and Guanine

6. Explain how a DNA double helix is formed using complementary base pairing and hydrogen bonds.

a. Nitrogenous bases from two single strands are joined using the complimentary base-pairing rule. Adenine with Thymine (using two hydrogen bonds) and Cytosine with Guanine (using three hydrogen bonds).

7. Draw and label a simple diagram of the molecular structure of DNA using the image library below. You will need to make a double strand four nucleotides long showing the covalent and hydrogen bonds. You will need to rotate some of the images (ask a friend to show you how if you don’t already know.)

Hydrogen bondCovalent bond

Guanine

Adenine Thymine

Cytosine