Class Notes 1: DNA
That stands for: DEOXYRIBONUCLEIC
ACID
I. What does DNA do?
A. DNA holds all the information that
determines what an organism is.
B. It is a set of instructions that tells each
cell what types of proteins to make.
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.
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)
** Diagram of one nucleotide
Nitrogenous
base
Phosphate
group
Deoxyribose
(sugar)
C. There are four nucleotides in DNA
Adenine
PURINES
Guanine
Thymine PYRIMIDINES Cytosine
Summary
Where exactly is DNA located? (from your lab)
What is the general structure of DNA?
What are the subunits of DNA?