1. DNA
(deoxyribonucleic acid)

2. Primary Roles of DNA
 Store Information
 Copy Information
– A cell must make a complete copy of its
DNA before the cell divides
 Transmit Information
– DNA molecules must be carefully sorted
and passed along when cells divide

3. Vocabulary
 Nucleic acid – molecule that is
essential for life
– Long molecule found in a cell’s
nucleus
– Made of smaller subunits
– Examples are DNA and RNA

4. Vocabulary (cont.)
 Nucleotides
–Have 3 parts
 A 5-carbon sugar (deoxyribose or
ribose)
 A phosphate group
 A base that contains Nitrogen
–Adenine, Guanine, Cytosine,
Thymine

5. Structure of DNA
 Nucleic acid made of
nucleotides
 Double helix model
– Looks like a twisted ladder
 Base pairing – bonds in
DNA can form only
between adenine and
thymine or between
guanine and cytosine

6. Structure of DNA
 Nucleic acid made of
nucleotides
 Double helix model
– Looks like a twisted ladder
 Base pairing – bonds in
DNA can form only
between adenine and
thymine or between
guanine and cytosine