DNA stores and transmits genetic information by making copies of itself when cells divide. It is made up of nucleotides containing a sugar, phosphate, and nitrogenous base. DNA takes the form of a double helix structure where the bases on each strand bond specifically with each other through base pairing between adenine and thymine or guanine and cytosine.

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