3. Looking at the Structure of DNA
Unraveling DNA
Looking at the Structure of DNA
Bases Form Codes

4. HOW DNA WORKS The structure of DNA allows DNA to hold information.
UNRAVELING DNA
GENES AND PROTEINS
The structure of DNA allows DNA to hold information.
The order of the bases G,C,A,T on one side of the DNA molecule is CODE that carries information
DNA is read like a book
Groups of 3 bases (G,C,A,T) are CODED for “specific” amino acids
CGA= amino acid “proline”
AGC= amino acid “serine”
a long string of amino acids form a protein

5. HOW DNA WORKS GENES AND PROTEINS GENES AND PROTEINS
A GENE is a string of nucleotides that give the cell information about how to make a specific trait
(example: hair color, eye color)
Each GENE is usually a set of instructions for making a protein
PROTEINS are related to traits because they cause most “chemical triggers” and messengers/processes in cells
One single organism can have thousands of genes that “code” for thousands of proteins.

6. HOW DNA WORKS HELP FROM RNA
Another type of molecule that helps make proteins: ribonucleic acid
RNA is similar to DNA
RNA can serve as a “temporary” copy of DNA sequence
Several forms of RNA help in the process of changing the DNA code into proteins

7. The Making of Protein
Copy one side of the segment of DNA containing a GENE
Mirrorlike copy of DNA is made of RNA
This copy is called “messenger” RNA
It moves out of the nucleus and into the cytoplasm
2. In the cytoplasm the messenger RNA is fed through a protein assembly line. The factory that “runs” this is the RIBOSOME. The messenger RNA is “fed” through the ribosome 3 bases at a time (G,C,A,T)

8. The Making of Protein
3. Molecules of transfer RNA translate the RNA message 4. Each transfer RNA molecule “picks up” a specific AMINO ACID from the cytoplasm 5. Inside the ribosome, bases on the transfer RNA match up with bases on the messenger RNA like pieces of a puzzle
6. The transfer RNA molecules release their AMINO ACIDS 7. The amino acids become linked in a growing chain 8. As the entire segment of messenger RNA passes through the ribosome, the growing chain of amino acids folds up into a NEW PROTEIN MOLECULE!