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Cytology

Cytology. Study of cells ~70 trillion = human body. Cells. Cells vary greatly in SIZE and STRUCTURE two main parts - NUCLEUS & CYTOPLASM, Enclosed in a CELL MEMBRANE (also called PLASMA MEMBRANE). Cell Membrane. Extremely thin Outpouchings and infoldings Porous

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Cytology

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  1. Cytology Study of cells ~70 trillion = human body

  2. Cells • Cells vary greatly in SIZE and STRUCTURE • two main parts - NUCLEUS & CYTOPLASM,Enclosed in a CELL MEMBRANE (also called PLASMA MEMBRANE)

  3. Cell Membrane • Extremely thin • Outpouchings and infoldings • Porous • Selectively Permeable = controls what enters and leaves the cell, it allows some things to pass but not others

  4. Membrane Structure • Lipids, proteins, carbs • Phospholipidbilayer

  5. CYTOPLASM - area b/w the plasma membrane and nucleus. • metabolic reactions/activities take place. • Filled with a clear fluid called CYTOSOL. • Contains ORGANELLES

  6. Cytoskeleton- • protein rods/ tubules

  7. Microfilaments- tiny rods of the protein actin • Various cell movements • Microtubules- long slender tubes of globular protein tubulin. • Maintain shape of cell • move organelles in cell

  8. Organelles • Ribosome- • Protein/RNA • Structural support • Link amino acids together to form proteins

  9. Endoplasmic Reticulum- • Smooth ER- • contains enzymes that synthesize lipids, absorb fats from digestive tract, break down drugs. • Rough ER- Contains Ribosome • Site of Protein Synthesis • Send to Golgi Apparatus

  10. Golgi Apparatus- • proteins arrive in vesicles from ER • Modifies proteins chemically • Send proteins in vesicles out of cell (vesicle trafficking)

  11. Vesicles- membranous sacs that vary in size/contents

  12. Mitochondria- 2 layers of membranes • Cristae- folded inner membrane • Matrix- fluid inside membranes • Captures/Transfers energy in the form of ATP

  13. Lysosome- • acts as garbage disposal • Break down proteins, carbs, nucleic acids • Destroy worn cell parts

  14. Peroxisomes- contain enzymes • Catalyze chemical reactions • Synthesis of bile acids • Breakdown of lipids • Degradation of rare biochemicals • Detoxification of alcohol

  15. Centrosome- two hollow cylinders (centrioles) • Made of microtubules • From spindle fibers to move chromosomes during mitosis

  16. Cilia/Flagella- • motile extensions of certain cells

  17. Nucleus • Spherical structure • Contains DNA

  18. Nuclear Envelop- double layered membrane • Nuclear pores- allow substances in and out • Nucleoplasm- fluid inside • Nucleolus- Site of ribosome production • Ribosomes move out nuclear pores • Chromatin- DNA fibers • Form chromosomes in mitosis

  19. MEMBRANES • phospholipidbilayer • 2 Tails- Hydrophobic • Head- Hydrophilic • Controls movement of substances in and out of cell

  20. Peripheral proteins • Integral proteins • Function • Help communicate with other cells • Transport substances across membrane

  21. Subs move throughout membrane

  22. Passive Transport • Diffusion- movement of particles from a concentrated area to a less concentrated area • Equilibrium Diffusion Example

  23. Diffusion

  24. Passive Transport • Osmosis - transport of water across membrane from a high concentration to a lower concentration • Hypertonic • Hypotonic • Isotonic

  25. Passive Transport Facilitated Diffusion - Transport proteins = pathway for molecules to pass through membrane

  26. Active Transport • Uses Energy • Moves against concentration gradient • Some Carrier proteins act as pumps

  27. Sodium Potassium Pump • Na+ binds to carrier protein inside cell • Carrier protein splits Phosphate group from molecule of ATP and phosphate group binds • ATP supplies energy needed to reshape protein • With new shape moves Na+ outside cell, and the shape is perfect to bind for K+ • Repeats

  28. Active Transport • Exocytosis- vesicles exports product from cells • Endocytosis- vesicle takes material into cell • Pinocytosis- transports of solutes or fluids • Phagocytosis-movement of large particles or whole cells

  29. Cell Life Cycle • Mitosis = nuclear division • followed by cytokinesis • The steps of mitosis ensure that each new cell has the exact same number of chromosomes as the original

  30. Interphase • 90% of cells life • G1 – growth phase • S phase (synthesis) – genetic material replicates • G2 – synthesize structures

  31. Mitosis

  32. Prophase • 1. chromosomes visible (chromatids) • 2. centrioles migrate to the poles • 3. nuclear membrane disappears • 4. nucleolus disappears • 5. spindle forms

  33. Metaphase • chromosomes line up on the equator, spindle attaches

  34. Anaphase • chromatids separate and move to opposite poles

  35. Telophase • 1. chromosomes disappear • chromatin • 2. nuclear membrane reforms • 3. nucleoli reappears • 4. spindle disappears • 5. centrioles duplicate

  36. Cytokinesis • division of the cytoplasm to form 2 new daughter cells • - organelles are divided • - daughter cells are genetically identical

  37. Karyotype

  38. Homework • Draw and label the phases of mitosis • Label : Centromere, centrioles, spindle fibers, and sister chromatids

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