1. Basics of RNA structure

2. RNA functions Storage/transfer of genetic information Genomes many viruses have RNA genomes single-stranded (ssRNA) e.g., retroviruses (HIV) double-stranded (dsRNA) Transfer of genetic information mRNA = "coding RNA" - encodes proteins

3. RNA functions Structural e.g., rRNA, which is a major structural component of ribosomes BUT - its role is not just structural, also: Catalytic RNA in the ribosome has peptidyltransferase activity Enzymatic activity responsible for peptide bond formation between amino acids in growing peptide chain Also, many small RNAs are enzymes "ribozymes"

4. RNA functions Regulatory Recently discovered important new roles for RNAs In normal cells: in "defense" - esp. in plants in normal development e.g., siRNAs, miRNA As tools: for gene therapy or to modify gene expression RNAi RNA aptamers Aptamers : are oligonucleic acid that bind to a specific target molecule.oligonucleic acid

5. RNA types & functions Types of RNAsPrimary Function(s) mRNA - messengertranslation (protein synthesis) regulatory rRNA - ribosomaltranslation (protein synthesis) t-RNA - transfertranslation (protein synthesis) hnRNA - heterogeneous nuclearprecursors & intermediates of mature mRNAs & other RNAs scRNA - small cytoplasmicsignal recognition particle (SRP) tRNA processing snRNA - small nuclear snoRNA - small nucleolar mRNA processing, poly A addition rRNA processing/maturation/methylation regulatory RNAs (siRNA, miRNA, etc.) regulation of transcription and translation, other??

6. Types of RNA Genetic information copied from DNA is transferred to 3 types of RNA: __________ RNA: mRNA Copy of information in DNA that is brought to the ribosome and translated into PROTEIN by tRNA & rRNA. ( 2%), 100,000 KINDS. __________ RNA: rRNA Most of the RNA in cells is associated with structures known as ribosomes, the protein factories of the cells.(80%), FEW KINDS It is the site of translation where genetic information brought by mRNA is translated into actual proteins. ___________ RNA: tRNA Brings the amino acid to the ribosome that mRNA coded for. (15%), 100 KINDS.