Class Notes 1: DNA

1
Class Notes 1 DNA

• That stands for DEOXYRIBONUCLEIC ACID

2
I. What does DNA do?

1. DNA holds all the information that determines
   what an organism is.
2. It is a set of instructions that tells each cell
   what types of proteins to make.

3
II. What is the structure of DNA?

• A. As we have seen, DNA is a long, skinny,
  molecule.
• 1. If we could see it more closely, we would see
  2 strands, connected like a ladder.
• 2. The ladder is twisted in a double helix.

4
B. DNA is made of smaller, sub- units called
nucleotides

• 1. Nucleotide - The basic unit of structure to
  form the DNA molecule
• 2. Three basic parts of a nucleotide
• Deoxyribose - a sugar made of 5 carbon atoms
• Phosphate group
• Nitrogen base (this part is different depending
  on the type of nucleotide)

5
Diagram of one nucleotide
Nitrogenous base
Phosphate group
Deoxyribose (sugar)
6
C. There are four nucleotides in DNA
Guanine
PURINES
Adenine


Cytosine
Thymine
PYRIMIDINES


7
Summary

• Where exactly is DNA located? (from your lab)
• What is the general structure of DNA?
• What are the subunits of DNA?