Review - Functional Groups- Mitosis/Meiosis- Mendel’s Laws- Prokaryotes vs. eukaryotes,- Tonicity (hypertonic,hypotonic, isotonic)- Anabolic vs catabolicOld Exams, study guides and end of the chapter reviewsCh. 5 and 6!Chapter 11 208-210Chapter 18 356-366Chapter 11 Cell SignalingControlling chromatin structureRegulating transcription initiationPost-transcriptional regulationInrotductionGene Regulation?- on/off- location, timing, amountWhy do genes need to be regulated?How are genes regulated? Cell Communication and Signaling- External signalso Source of signals Local- Paracrine Signaling- Synaptic signaling  Long-distance- Endocrine Signalingo Types of signals: Protein, lipid, ion, carbohydrateo Highly conserved-evidence for evolutionary relatednessBasic steps of a signal transduction pathway- Reception- most in the cell membrane; the binding event causes the protein to change or breakoff and becomes a relay model- Transduction-- Response- cells change shape or expresses a new set of genes RNA Polymerase II transcribes the GeneChapter 18Regulating Gene Expression1. Chromatin Structurea. 8 histone proteins + DNA = Nucleosomei. Histone modifications (to tails) (Fig 18.7)1. Add acetyl groups to loosen2. Add methyl groups (-CH3) to condense (not shown)ii. DNA modifications2. Regulation of transcription initiationa. Enhanceri. DNA sequence where cell type specific TFs bindb. Promoteri. DNA sequence where general TFs bind, attracting RNA Polc. Terminationi. DNA sequence where RNA Pol stopsd. Pre-RNA transcript-exons + introns + poly A signalSpefict TFs/Activator proteinsDNA binding domain-enhancerActivation domain—mediatorsGeneral TFsDNA binding domain—promoterActivation Domain—mediators, RNA Pol3. Post-Transcriptional