DNA, RNA, and Protein Synthesis Ch 12 section 3

A. Learning Goals Tell how DNA differs from RNA Describe the role of the ribosome during protein synthesis. Compare and contrast Transcription and translation Break down the Genetic Code…from DNA TACCGATCATGGATT

A. DNA: Deoxyribonucleic Acid Double strand of nucleotides, called double helix. Each nucleotide consist of 1. deoxiribose sugar 2. phosphate and 3. base Basis are adenine, guanine, thymine, cytosine. DNA is a genetic library, the original blueprints!! Discovered by Watson and Crick DNA From The Beginning

B. RNA- Ribonucleic acid Single strand of nucleotides Each nucleotide consist of 1. Ribose sugar 2. A phosphate group 3. Nitrogen base Uracil instead of thymine !!!!! U and A, C and G *RNA is a working copy of DNA

C. Base Pairing: Chargoff’s Rules In DNA… Adenine always pairs with Thymine Cytosine always pairs with Guanine Question: If you have 5673 cytosines in a strand of DNA, how many guanines will you have? Answer: 5673 In RNA… Thymine is replaced by Uracil DNA TACATTGACCGATT RNA AUGUAACUGGCUAA

D. Central Dogma for Protein Synthesis…The Big Idea!!! Protein synthesis… the making of proteins by putting Amino Acids together! transcription translation Dna Rna protein Nucleus cytoplasm ribosome

E. Three types of RNA Messenger RNA, mRNA: carry message with instructions for making proteins.Every three bases makes a codon. Ex. AAG Ribosomal RNA, rRNA: part of the ribosome, proteins are assembled here. Transfer RNA, tRNA; transfers amino acid to the ribosome as it is read by mRNA. Every three bases make one anticodon Ex. UUC

F. Transcription: making a copy of the original message (like taking notes) Start ( ) and stop signals ( ) direct beginning and end of note taking. mRNA make a summary: it takes out the info that does not code for proteins . Introns are junk DNA! It keeps the exons which will code for proteins. Exons yes, introns no! animations

G. TRANSLATION: making sense of the genetic language mRNA codons are transcribed in nucleus, exits to cytoplasm to attach to ribosome. tRNA brings the anticodon with the right amino acid to the ribosome. The Amino acid is added to the polypeptide chain. Ex. DNA AGCTTA mRNA UCG-AAU ( each 3 are a codon) tRNA AGC-UUA (each 3 are an anticodon) amino acid serine aspargine protein ser-asp animations

H. Proteins Can be from 2 to ____ amino acids long. There are 20 types of amino acids Your DNA codes for proteins. These proteins contribute to how you look and how you function. Can very in the sequence (order) and in the number of amino acids!! Race the Cell