13.3 RNA & Gene Expression I. An Overview of Gene _____________ A. RNA 1. __________Acid – essential in taking the genetic information from DNA & building proteins B. Gene _____________ 1. the manifestation of genes into specific traits II. DNA vs. RNA A. RNA differs in _____________ ways

1. only one stranded 2. contains ribose instead of deoxyribose 3. has ____________(U) instead of thymine (T) III. Types of RNA A. _____________ RNA (mRNA) 1. Complementary to DNA 2. carries instructions for making a protein from a gene & delivers them to the site of translation B. _____________ RNA (tRNA) 1. reads the mRNA sequence 2. translates the mRNA sequence into a specific sequence of amino acids C. _____________ RNA (rRNA) 1. found only in ribosomes

IV. Transcription A. the making of RNA from the info in DNA B. happens in nucleus of eukaryotic cells C. Begins at promoter (start signal of DNA) D. RNA polymerase unwinds & separates the gene (section of DNA)

E. Follows the base pairing rules with the E. Follows the base pairing rules with the change of uracil (U) for ___________(T) creating a complementary strand of mRNA F. Eventually reaches the stop location G. Results in a single strand of mRNA V. The Genetic Code: Three Letter “Words” A. _____________ 1. each three nucleotide sequence 2. each codon is matched up to 1 of 20 amino acids

3. Examples a. AUG codes for b. CAU codes for c. AGU codes for d. UGA codes for start histidine serine stop

VI. _____________ A. uses the info in RNA to make a specific protein B. happens in cytoplasm of eukaryotic cells C. Occurs in a sequence of steps, involves three kinds of RNA, & results in a complete polypeptide