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Chapter 12: Cell Cycle PowerPoint Presentation
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Chapter 12: Cell Cycle

Chapter 12: Cell Cycle

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Chapter 12: Cell Cycle

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Presentation Transcript

  1. Chapter 12: Cell Cycle

  2. Cell Division • Reproduction • Growth • repair • Genome • Chromosomes • Somatic cells • Gametic cells • Chromatin (duplicates) • Centromere • Sister chromatids

  3. Reproduction Growth and Development Tissue Renewal

  4. Mitosis vs. Meiosis • Mitosis division of nucleus • Cytokinesis division of cytoplasm • Meiosis produces gametes • Mitosis produces clones

  5. The cell cycle • The Cell Cycle (cell growth) • Interphase (90%) • G1:cell growth • S:copies chromosomes • G2:preps for division • Mitotic phase (M)

  6. What’s the purpose of Interphase? • Cell growth, produce proteins • High Metabolic Activity • Prepares for division • Single centrosomes replicates • Centrosomes move apart • Spindle Poles form

  7. Magnificent Mitosis! • PPMAT • Prophase • Prometaphase • metaphase • anaphase • telophase

  8. Prophase • What happens to the chromatin? • What happens to the nucleolus? • Sister chromatids, centromere • What happens to the nuclear envelope (membrane)?

  9. Prometaphase • Nuclear envelope dissolves • Microtubules of the spindle contact chromosomes (kineticore)

  10. Metaphase • “Meet in the Middle” • spindle microtubules • centrioles

  11. Anaphase • Sister chromatids separate and move to opposite poles (now called chromosomes) • spindle microtubules • centrioles

  12. Telophase and Cytokinesis • Reverse of prophase • chromatin • nucleoli • nuclear envelope • Cytokinesis

  13. Cytokinesis :a closer look • Cleavage Furrow • Occurs along old metaphase plate • Actin Microfilaments • “pulling of drawstrings” • Plants form a “cell plate” vesicles move to middle. • Cell plate fuses with plasma membrane

  14. Molecular Control • Regulation by internal and external checkpoints • G1 in mammals, if stop cell arrests in G0 phase. (nerve cells always in G0) • Cyclin dependent Kinases (Cdks) • Cyclins bind to Cdks during G2, forming MPF complex which initiates mitosis • Growth Factors: PDGF • Anchorage Dependent

  15. Checkpoints

  16. Cell Cycle Clock • Kinase Dependent: enzymes that activate or inactivate other proteins by phosphorylation. • Cyclin: protein kinase must be attached to, for enzyme to be active. Constant Conc. of Enzyme, varying conc. of cyclin • MPFs (maturation promoting factor) first Kinase discovered.

  17. Control Link Cell Cycle Game

  18. Cancer • Cancer cells • Benign tumor • Malignant tumor • Metastasis • Proto-oncogenes • Oncogenes