Welcome to General Principles and Concepts of Biology!Today’s Goals:Next Time:Extra Credit!PowerPoint PresentationI. Cell DivisionSlide 7Slide 8Slide 9Slide 10Slide 11Slide 12Slide 13Slide 14Slide 15Slide 16Slide 17Slide 18Slide 19Slide 20Slide 21Slide 22Slide 23Slide 24Proto-oncogenesTumor suppressorsSlide 27“Multiple Hits” modelSlide 29II. MutationsSlide 31Slide 32Welcome to General Principles and Concepts of Biology!BioSci 1010, Sec. 2ANNOUNCEMENTS:Enjoy Parents’ Weekend!Exam #1:Answer key postedMasteringBiology-cancerDue Wednesday @ 11:55pmNew grading defaultsSuperheroes and supervillains of the circulatory system: Auntie Oxidant kicks out the Free Radicals.Today’s Goals:Readings: Chapter 6.1-6.4I. Cell DivisionA. What is cancer?B. Purpose of cell divisionC. Main stepsD. DNA replicationE. MitosisF. CytokinesisG. Cell cycle: cancer short-circuitsII. MutationNext Time:Readings: Chapter 7III. Inheritance of traitsA. What is a gene?B. Single genes (Mendelian)C. Many genes (Quantitative)Extra Credit!Last name starts with…Come in the week of…A-D September 1st E-J September 8th K-P September 15th R-Z September 22ndU2 IC1Name 1 Student #1 Signature 1Name 2 Student #2 Signature 21. Pretend that you are DNA polymerase: pair the correct nucleotides with this single strand of DNAA T C C G T T A C GT A G G C A A T G C2. Draw a cell with 2 types of chromosomes after DNA replication. Label: sister chromatid, centromere, homologous chromosomesI. Cell Division2. The story of mitosis:b. Metaphase: i. Chromosomes line up in center of cellI. Cell Division2. The story of mitosis:c. Anaphase:i. spindle proteins shorten, pulling sister chromatids apart.http://www.youtube.com/watch?v=o6u7RUwT8pYI. Cell Division2. The story of mitosis:c. Anaphase:i. spindle proteins shorten, pulling sister chromatids apart. ii. Each chromatid is now a chromosomeI. Cell DivisionE. Mitosisd. Telophase: i. Spindle dissolvesI. Cell DivisionE. Mitosisd. Telophase: i. Spindle dissolves ii. Nuclear envelopes reformI. Cell DivisionE. Mitosisd. Telophase: i. Spindle dissolves ii. Nuclear envelopes reform iii. Chromosomes unwindReview steps of mitosis with neighborI. Cell DivisionMain stepsD. DNA ReplicationE. Mitosis - division of the nucleusF. Cytokinesis - division of the rest of the cytoplasm.I. Cell DivisionF. Cytokinesis1. The cell itself divides in half creating two identical daughter cellsI. Cell DivisionF. Cytokinesis1. The cell divides in half 2. Animal cells produce a band of proteins that pinch the cell in halfhttp://www.youtube.com/watch?v=H2HmRnYLDhAI. Cell DivisionA. What is cancer?B. Purpose of cell divisionC. Main stepsD. DNA ReplicationE. MitosisF. CytokinesisG. Cell Cycle: How does cancer break the rules?I. Cell DivisionG. Cell cycle: life cycle of the cellI. Cell DivisionG. Cell cycle1. Tightly controlled process: cells given signals when to dividea. Normal cells halt at checkpoints b. Proteins survey the condition of the cellc. Cell must pass the survey to proceed with cell divisiond. Three checkpoints: G1,G2, and metaphaseI. Cell Divisiond. Three checkpointsi. Early interphase (G1): Growth factors (O) stimulate cells to divide by binding to receptors (Y) on cellI. Cell Divisiond. Three checkpointsi. Early interphase: ii. After DNA replication (G2): Was DNA replicated correctly?I. Cell Divisiond. Three checkpointsi. Early interphase: ii. After DNA replication:iii. Mitosis: Are chromosomes attached to spindle fibers?I. Cell DivisionG. Cell cycle1. Three checkpoints2. If conditions not favorable (“NO” at a checkpoint), process of cell division is halted (cell may die)I. Cell DivisionG. Cell cycle1. Three checkpoints2. Cell division halted in unfavorable conditions3. When genes coding for regulatory proteins are mutated, proteins don’t work and cell division not regulatedI. Cell DivisionG. Cell cycle3. Mutated (non-functioning) regulatory proteinsa. Proto-oncogenesb. Tumor suppressors© 2013 Pearson Education, Inc.Proto-oncogenesProto-oncogenes: genes that code for the cell cycle control proteins (such as receptors and growth factors)When proto-oncogenes mutate, they become oncogenesTheir proteins no longer properly regulate cell divisionThey usually overstimulate cell divisionExample: HER2 receptor always “on”, ovarian cancer© 2013 Pearson Education, Inc.Tumor suppressorsTumor suppressor genes: genes for proteins that stop cell division if conditions are not favorableCan detect and repair damage to DNA (backup if proto-oncogenes mutated)When mutated, can allow cells to override checkpointsEx: p53 mutants allow damaged DNA to proceed through mitosis; involved in half of all cancers.I. Cell DivisionG. Cell cycle1. Three checkpoints2. Cell division halted in unfavorable conditions3. Mutated regulatory proteins allow unchecked cell division4. Most cancers require more than one mutation“Multiple Hits” modelATGTTCGTACAAGCWhat is a mutation?Are they always bad?A. Mutation: changes to the sequence of nucleotides in a stretch of DNAATGTTCGTACAAGCTACGAGCATGCTCGII.