Class 3-cell division & mito

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cell devision and mitosis

Transcript of Class 3-cell division & mito

  • 1.Cell Cycle The process of cell growth and division in eukaryotes is called cell cycle.This cycle is divided into phases based on what is happening in the cell at a given time.A cell grows during the G1 phase. During the phase there is chemical checkpoint that controls whether the divide, delay division or enter the division stage. When conditions in the cell are right, the G1 checkpoint will be passed and the cell will enter the synthesis(S) phase.During the S phase DNA replication occurs so that future cells will each have a complete set of genetic instructions in the DNA.

2. Cell Cycle After DNA replication is complete cells enter the G2 phase, where they continue to grow and prepare for cell division. At a checkpoint in this phase the success of DNA replication is assessed; if all is well the cell enter the mitosis (M) phase.During the M phase, a complex series of events moves the DNA so that a complete set of genetic instructions will be sent to each daughter cell. The process of mitosis is assessed at a checkpoint during the M phase.Once this checkpoint is passed, the cell will complete the mitosis as well begin the cytokinesis(C) phase. Part or all of the C phase overlaps with the later part of mitosis, so it is not a distinctly separate phase.During the C phase the cytoplasm of the cell is divided and two daughter cell are created from the original cell. When this process is finished the daughter cell enter the G1 phase, and the cell cycle is complete. 3. Chromosome Chromosome, microscopic structure within cells that carries the molecule deoxyribonucleic acid (DNA)the hereditary material that influences the development and characteristics of each organism. A human body cell usually contains 46 chromosomes arranged in 23 pairs. 4. Through research and the development of staining techniques in the 1950's, scientists were for the first time able to view the human chromosome. Although they appear disorganised within the cell, scientists have been able to identify them and so have numbered them from 1-22 in order of size. 5. Eukaryotic Chromosomes Located in the nucleus Each chromosome consists of a single molecule of DNA and its associated proteins The DNA and protein complex found in eukaryotic chromosomes is called chromatin 1/3 DNA and 2/3 protein Complex interactions between proteins and nucleic acids in the chromosomes regulate gene and chromosomal function 6. Cell division All complex organisms originated from a single fertilised egg. Every cell in your body started here, through cell division the numbers are increased Cell then specialise and change into their various roles 7. Mitosis and Meiosis Mitosis: -division of somatic (body) cells Meiosis -division of gametes (sex cells) 8. Mitosis Mitosis is the process by which new body cell are produced for: Growth Replacing damaged or old cells. This is a complex process requiring different stages 9. Mitosis All daughter cells contain the same genetic information from the original parent cell from which it was copied. Every different type cell in your body contains the same genes, but only some act to make the cells specialise e.g. into nerve or muscle tissue. 10. Mitosis Interphase Prophase Metaphase Anaphase Telophase 11. Interphase Interesting things happen! 1. Cell preparing to divide 2. Genetic material doubles 12. Prophase Chromosome pair up! 1. Chromosomes thicken and shorten -become visible -2 chromatids joined by a centromere 2. Centrioles move to the opposite sides of the nucleus 3. Nucleolus disappears 4. Nuclear membrane disintegrate 13. Metaphase Chromosomes meet in the middle! 1. Chromosomes arrange at equator of cell 2. Become attached to spindle fibres by centromeres 3. Homologous chromosomes do not associate 14. Anaphase Chromosomes get pulled apart 1. Spindle fibres contract pulling chromatids to the opposite poles of the cell 15. Telophase 1. 2. 3. 4. 5.Now there are two! Chromosomes uncoil Spindle fibres disintegrate Centrioles replicate Nucleur membrane forms Cell divides 16. Meiosis 4 daughter cells produced Each daughter cell has half the chromosomes of the parent 2 sets of cell division involved 17. Mitochondria Mitochondria are membrane-enclosed organells distributed through the cytosol of most eukaryotic cells. Their main function is the conversion of the potential energy of food molecules into ATP. Every type of cell has a different amount of mitochondria. There are more mitochondria in cells that have to perform lots of work, for example- your leg muscle cells, heart muscle cells etc. Other cells need less energy to do their work and have less mitochondria. 18. MitochondriaDouble membrane with shelf-like cristaeMatrix: Substance located in space formed by inner membrane.Provide most of the cells ATP via aerobic cellular respirationMitochondrial enzymes catalyze series of oxidation reactions that provide about 95% of cells energy supplyEach mitochondrion has a DNA molecule, allowing it to produce its own enzymes and replicate copies of itself.structure 19. The Mighty Mitochondrion! Powerhouse of the CellATP 20. Mitochondria 1) 2) 3) 4) 5)TCA cycle Fatty acid oxidation Amino acid oxidation Gluconeogenesis Synthesis of organelle protein 21. ProteinsAmino acidsOuter Membrane: Freely permeable to small molecules and ions Inner Membrane: impermeable to most small molecules and ions, including H+ Contains: Respiratory electron carriers (complexes IIV) ATP Synthase Other membrane transportersFatsSugarsGlycerolGlycolysis GlucoseGlyceraldehyde-3-NH3Matrix Contains: Pyruvate dehydrogenase complex Citric acid cycle enzyme Fatty acid -oxidation enzymes Amino acid oxidation enzymes DNA Ribosomes Many other enzymes ATP, ADP, Pi, Mg+2, Ca+2, K+ Many Soluble metabolic intermediatesCarbohydratesPPyruvateAcetyl CoACitric acid cycleOxidative phosphorylationFatty acids 22. Electron shuttles span membraneCYTOSOL2 NADHGlycolysis Glucose2 PyruvateMITOCHONDRIO N2 NADH or 2 FADH2 6 NADH2 NADH2 Acetyl CoA+ 2 ATPCitric acid cycle+ 2 ATPMaximum per glucose:2 FADH2Oxidative phosphorylation: electron transport and chemiosmosis+ about 32 or 34 ATPAbout 36 or 38 ATPRodney-464 page 23. ChloroplastLargest organelles of plants and algaeVary in size and shapeFunction: PhotosynthesisInner membrane system Grana thylakoids Stroma Calvin cycle sugar synthesisGenomeHas its own protein synthesizing enzymesConverts light energy to chemical energy (sugars) 24. Chloroplasts 25. Chloroplast Granum StromaOuter membraneInner membraneThylakoid lumenDo not post photos on InternetThylakoid membrane1 m 26. CO2H2OLight NADP+ ADP + PiLight ReactionsCalvin CycleATP NADPHChloroplast O2[CH2O] (sugar) 27. MitochondriaChloroplastAerobic respiration Mitochondria (all eukaryotic cells)Photosynthesis Chloroplasts (some plant and algal cells) LightCO2 Glucose +O2ATPCO2+RespirationH2OH2O+ ATPO2 + GlucosePhotosynthesis 28. Chloroplasts 1)Photosynthesis2)Fatty acid synthesis3)Complex lipid synthesis4)Synthesis of some amino acids5)Synthesis of organelle protein6)Calvin cycle7)Light reaction8)Reduction of nitrate and sulphate9)Part of photorespiration