Biochemistry

Signal Transduction Mechanisms 4/12/16 Yeast Can be diploid or haploid If a cell can recognize the presence of another cell nearby it develops a schmoo which allows the cells to mate Cell communication is more complicated in multicellular organisms Multiple potentials before differentiation Communication is crucial Signal transduction moves information from the cell surface to the nucleus & other cellular targets Converts an outside message into a change in cell behavior Signal transduction Extracellular signal is converted to intracellular signals that direct cell behavior Cell communications depends on: Extracellular signal molecules Receptor proteins Intracellular signaling proteins Target proteins What type of molecules can be used as extracellular signals? Proteins

DNA Transcription (Slide 20) The ?Central Dogma? - Crick 1958 DNA - RNA - Protein Proposed that this process could not go backwards The part of DNA that encodes for a protein (or RNA) is called a gene GENE: Functional unit of DNA that codes for one or more polypeptide chains or an RNA molecule Genome is not just genes, there are intervening sequences that don?t code for a protein Proteins are generated through transcription and translation How much protein is present can be regulated by the amount of transcription and/or translation Beta-catenine- high abundance in brain (A) but low abundance in muscle (B) DN A is transcribed by RNA polymerase One RNA polymerase in bacteria that does all the transcription CORE ENZYME: 2?, 1?, 1??