1. Genes are read and copied before use! DNA: DeoxyriboNucleic Acid RNA: RiboNucleic Acid The instructions that are needed by the cell are copied from the DNA into a similar molecule called R NA The nucleus READS the genes and sends INSTRUCTIONS in the form of RNA “messages” Nucleus Each gene is copied into RNA when it is needed by the cell

2. What Kind of Stuff Are You Made Of? http://gened.emc.maricopa.edu/bio/bio181/BIOBK/BioBookAnimalTS.html Cells lining a tubule Fat cells Muscle cells Red blood cells Cells lining the small intestine Cell types in the stomach Nerve cells Cells: The fundamental unit of life The building blocks of bodies We are each made of 100 trillion cells!

3. Different Cell Types Make Different Organs http://gened.emc.maricopa.edu/bio/bio181/BIOBK/BioBookAnimalTS.html Cells lining a tubule Fat cells Muscle cells Red blood cells Cells lining the small intestine Cell types in the stomach Nerve cells What makes cells different from each other? Gene Expression Each cell type does a different job They must not get “mixed up”! What makes these cells differentiate?

4. DNA (GENE) PROTEINS mRNA AAAAAAAAAA DNA is copied into RNA: DNA letters copied into RNA code. The RNA code specifies the order of amino acid building blocks in the protein. The amino acid chain folds to make a functional 3D protein. Messenger RNA Flow of Genetic Information: DNA to RNA to Protein

5. A DNA Spelling Mistake Can Alter the Protein Chain ATG TTC AGG CCA AAT TTT GTC GCG UAA GGA ATT STARTADD STOP TTC to TTT spelling change causes a different protein building block to be inserted in the second position. That is all it takes. Spelling Mistake The DNA “word” TTC is changed to TTT ATG TTT AGG CCA AAT TTT GTC GCG