DNA Review  Contains the genetic instructions used in the development and functioning of all organisms  Found in the nucleus of cells!  Made up of Nucleotides  Sugar (deoxyribose)  Phosphate  Nitrogenous Base Adenine Thymine Cytosine Guanine

DNA Replication  1 DNA strand 2 DNA strands  The first DNA strand acts as a template for the newly formed strand of DNA  DNA polymerase copies the new strand of DNA  Practice replicating DNA!!!

 Single stranded  Sugar is Ribose  DNA = Deoxyribose  Copied from DNA during a process called transcription  Made up of nucleotides  Does not contain thymine  Uracil (U) replaces thymine in RNA strand

DNA vs. RNA  DNA ATT GAT CAT AGT  RNA AUU GAU CAU AGU

 mRNA- (messenger RNA) sends the message of DNA to the ribosomes  rRNA- (ribosomal RNA) make up ribosomes  (place of protein assembly)  tRNA- (transfer RNA) transfers the RNA message into proteins

 Makes RNA from DNA DNA- GCA CTA GTC ATC RNA- CGU GAU CAG UAG  End Result: 1 DNA strand 1 mRNA Strand

Transcription Steps  1. RNA polymerase, an enzyme, binds to DNA found in the nucleus and separates the DNA strands  2. RNA polymerase then uses one strand of DNA as a template for assembling a strand of mRNA that is then released into the cytoplasm.

REVIEW  DNA Replication  1 DNA Strand2 DNA Strands  Transcription  DNARNA  Translation  RNAProtein

Making Proteins  The sequence of nucleotides serves as instructions for the order of amino acids  Proteins are made from joining many amino acids into a long chain  The code is read 3 letters at a time

Codon  Every three nucleotides is a word known as a codon.  AGTTCCGAT  Each specific codon represents a single amino acid  Chains of amino acide make proteins  64 different codons

Translation  Decoding of a mRNA into a polypeptide chain or protein.  First mRNA is transcribed from DNA and released to the cytoplasm

5 Basic Steps in Translation  Step 1: A ribosome forms around a molecule of mRNA  needs the start codon AUG  Step 2: Each codon allows the proper amino acid to be brought into the ribosome by tRNA.  Step 3: The amino acids are attached together along an “assembly line” to form a chain.

 Step 4: The new protein grows as the codons are 'read‘  until a stop codon appears  Step 5: The completed protein is released.

Codons and Translation  Start codon- "AUG" - Methionine  signals initiation translation  Stop Codon- "UAG, UAA, and UGA"  signals termination of translation

Let’s practice decoding Codons!  UUUCAGGAA  AUACCGAGA  GCUGACUAC