Bell Ringer 1.What is the complementary DNA for the following strand TAC GCA ATG CCT? 2.Where does Protein Synthesis take place (Hint…Unit 3: Cell Organelles)? 3.If Protein is the “polymer”, what would be it’s “monomer” (Hint…Unit 2: Macromolecules)? 4.What was the analogy for an Protein (Hint…Unit 2: Macromolecules)?

Joke of the Day:

RNA and Protein Synthesis Transcription and Translation

Building Proteins Protein Synthesis: Building Proteins Gene: A segment of DNA that contains instructions for making proteins. RNA: (Ribonucleic Acid) - a working copy of a single gene.

RNA vs DNA Sugar = Ribose Single Stranded Contains Uracil Sugar = Deoxyribose Double Stranded Contains Thymine  Both contain nucleotides made of a Sugar, Phosphate and Nitrogenous Base!  Both contain Adenine, Guanine and Cytosine! Similarities between RNA and DNA:

Codon: (mRNA) a series of 3 nucleotides that code for a specific amino acid to be added to the chain. UCGCACGGU Anti-Codon: (tRNA) a group of 3 bases on a tRNA molecule that are complementary to a mRNA. mRNA = UCG-CAC-GGU tRNA = AGC-GUG-CCA Example:

3 Types of RNA Messenger RNA: (mRNA) Codon - carry messages from the DNA to the rest of the cell. Ribosomal RNA: (rRNA) found in the ribosomes where proteins are assembled Transfer RNA: (tRNA) Anticodon - transfers each amino acid to the ribosomes as it is needed

Transcription Transcription: Process where sections of DNA are copied into a complementary strand of mRNA (working copy). Happens in the nucleus. RNA Polymerase: the enzyme that aids in the process of transcription.

RNA DNA RNA polymerase Adenine (DNA and RNA) Cystosine (DNA and RNA) Guanine(DNA and RNA) Thymine (DNA only) Uracil (RNA only) Transcription

The Genetic Code Proteins are made by joining amino acids in long chains Monomer = Amino Acid Polymer = Polypeptide (Protein) The order of the amino acids determines the specific Protein.

Using the mRNA wheel to Interpret the Genetic Code! Start in the middle of the circle and move outward! UCG = Serine CAC = GGU = UAA =  There are 64 codons but only 20 amino acids. So, different codons can code for the same amino acid.

Steps of Translation Translation: the decoding of an mRNA message into a protein. 1.mRNA is transcribed from DNA 2.mRNA attaches to the ribosome 3.As each codon of the mRNA moves through the ribosome, the correct amino acid is carried in by the transfer RNA.  Each tRNA has an amino acid attached.  The anticodon on the tRNA matches the codon on the mRNA 4.As each amino acid is carried in, a bond forms between them and the Protein is assembled. 5.The chain continues to grow until it reaches a stop codon on the mRNA.

Peptide Bond

Messenger RNA Messenger RNA is transcribed in the nucleus. Transfer RNA The mRNA then enters the cytoplasm and attaches to a ribosome. Translation begins at AUG, the start codon. Each transfer RNA has an anticodon whose bases are complementary to a codon on the mRNA strand. The ribosome positions the start codon to attract its anticodon, which is part of the tRNA that binds methionine. The ribosome also binds the next codon and its anticodon. mRNA Start codon Ribosome Methionine Phenylalanine tRNA Lysine Nucleus mRNA

The Polypeptide “Assembly Line” The ribosome joins the two amino acids— methionine and phenylalanine—and breaks the bond between methionine and its tRNA. The tRNA floats away, allowing the ribosome to bind to another tRNA. The ribosome moves along the mRNA, binding new tRNA molecules and amino acids. mRNA Ribosome Translation direction Lysine tRNA Ribosome Growing polypeptide chain mRNA Completing the Polypeptide The process continues until the ribosome reaches one of the three stop codons. The result is a growing polypeptide chain.

imat/molgenetics/translation.swf

Bell Ringer: Use your mRNA wheel and translate the following codons into Amino Acids AUG AAA GUU GGC CCG CAA CCA UCA UGA START (MET) LYSVALGLYPROGLUPROSERSTOP