DeoxyriboNucleic Acid
Stores and passes on genetic information from one generation to another.

The DNA structure is shaped like a spiral staircase, or twisted ladder.
It is called a double helix.

DNA Structure
The outer parts of the double helix are made from sugars.

DNA STRUCTURE
The steps of the ladder are made of pairs of nitrogen bases

DNA STRUCTURE
1.Adenine = A
2.Guanine = G
3.Cytosine = C
4.Thymine = T
They are represented by their capital letter.

DNA STRUCTURE
There is only one way the nitrogen bases can form.
Adenine pairs with Thymine
Guanine pairs with Cytosine

DNA Structure
Base pairs are always the same
G
C
A
T
C T
G
A

DNA STRUCTURE
A C T C A T G G T C A T G
T G A G T A C C A G T A C
This is an example of a genetic code that may be found in your body.

DNA STRUCTURE
The combination of nitrogen bases is the code that produces the genes for a particular trait.

DNA STRUCTURE
Because there are so many different combination of bases the code can be limitless.

DNA STRUCTURE
Example:
ATCGTCAGG may be for hair color.
but
ATCGTCAGC may be for eye color.

DNA REPLICATION
Replication:
The process where
DNA molecules form an exact duplicate.

DNA REPLICATION
1. The ladder splits
2. Weak hydrogen bonds between the base pairs break
3. Free floating nitrogenous bases begin to pair with each strand
4. Two new DNA chains are formed http://www.youtube.com/watch?v=bW5JnYZImJA&feature=fvst

Weak chemical bonds
Free floating nitrogen bases

Protein Synthesis
•
The work of the cell is carried out by many types of molecules the cell assembles (synthesizes).
•
Many of these molecules are proteins.
• Protein molecules are long chains formed from 20 kinds of amino acids in a specific sequence.

Protein Synthesis
•
The sequence of amino acids influences the shape of the protein which enables it to carry out its function.

Protein Synthesis
•
Many proteins:
– are enzymes that regulate chemical reactions.
– become parts of organelles.
– are hormones such as insulin.
– are antibodies.
http://www.youtube.com/watch?v=983lhh20rGY

The DNA-Protein
Connection
•
Much of the coded information stored in genes is used to make proteins for cell function and structure.
•
These proteins are made at the ribosomes according to the directions stored in the
DNA.
•
Since a child inherits part of a parents
DNA, it could also inherit proteindependant traits such as hair texture
(straight or curly).

• J.R. Wanamaker from www.lew-port.com