Anatomy and Physiology Chapter 3 Cell Biology

  1. The Plasma/Cell Membrane
    • Forms the outer boundary of the cell
    • The fluid-mosaic model, lipids, proteins and some sugars
  2. The Plasma/Cell Membrane-Function
    • protects the cell
    • separation of intracellular vs. extracellular materials
    • is semipermeable, selectively permeable
  3. Glycocalyx
    the combination of carbohydrates and lipids (glycolipids) and proteins (glycoproteins) on outer surface of the plasma membrane
  4. Phospholipids Bilayer
    • polar heads facing the interior and exterior of the cell (hydrophilic)
    • nonpolar tails (the fatty acids) facing each other on the interior of the membrane (hydrophobic)
  5. Cholesterol
    • major lipid of plasma membrane
    • interspersed among the phospholipids
  6. Fluid nature of membrane lipids allows:
    • distribution of molecules within the membrane
    • the phospholipids reassembled if membrane is damaged
  7. Integral membrane proteins
    • extend deeply into membrane
    • functions as markers, attachment sites, channels, receptors, enzymes, or carriers
  8. Peripheral membranes proteins
    • attached to either the inner or outer surfaces of the lipid bilayer
    • functions as markers, attachment sites, channels, receptors, enzymes, or carriers
  9. Marker Molecules: Glycoproteins and Glycolipids
    allow cells to identify one another or other molecules
  10. Attachment Proteins
    intergral proteins that allow cells to attach to other cells or extracellular molecules
  11. Cadherins
    attach cells to other cells
  12. Integrins
    attach cells to extracellular molecule
  13. Types of Transport Proteins
    • channel proteins
    • carrier proteins
  14. Channel Proteins
    are one or more integral membrane proteins arranged so that they form a tiny channel through the plasma membrane
  15. Carrier Proteins/Transporters
    • have specific binding sites
    • could be- uniporters, symporters, antiporters
  16. Uniporters
    move one particle
  17. Symporters
    move two particles in the same direction
  18. Antiporters
    move two particles in opposite directions
  19. Enzymes
    act to catalyze reactions at outer/inner surface of plasma membrane
  20. Molecules can move by
    simple/passive or active means
  21. Passive Transport mechanisms
    • movement from high to low
    • diffusion
    • osmosis
    • facilitated diffusion
  22. Active Transport mechanisms
    • low to high concentration
    • require energy (ATP)
    • requires carrier protein
    • rate of transport depends on amount of ATP
  23. Simple diffusion
    movement of solutes from area of higher concentration to lower concentration in solution
  24. Osmosis
    • diffusion of water(solvent) across a selectively permeable membrane
    • water moves from an area of low concentration of solute to an area of high concentration of solute
  25. Isotonic
    • cell neither shrinks nor swells
    • concentration of solutes in solution equal to that inside the cell
  26. Hypertonic
    • cell shrinks (crenation)
    • solution having high solute concentration, water move out of the cell by osmosis
  27. Hypotonic
    • cell swells (lysis)
    • solution having low solute concentration, water enters the cell by osmosis
  28. Mediated Transport
    involve carrier proteins or channel proteins
  29. Specificity
    for a single type of molecule
  30. Saturation
    rate of transport limited to number of the available carrier proteins
  31. Facilitated Diffusion
    • molecules from high to low concentration and require carrier or channel proteins
    • move large water soluble molecules or electrically charged molecules across the plasma membrane
  32. Endocytosis
    • internalization of substances by formation of vesicles
    • 3 types- phagocytosis, pinocytosis, receptor-mediated endocytosis
  33. Phagocytosis
    cell eating
  34. Pinocytosis
    cell drinking
  35. Receptor-Mediated Endocytosis
    • receptor molecules on cell surface bind to molecules to be taken into the cell
    • the receptor and the bound molecules are taken into the cell as a vesicle begins to form
    • the vesicle fuses and separates from the plasma membrane
  36. Exocytosis
    • a secretory vesicle moves towards the plasma membrane
    • the secretory vesicle fuses with the plasma membrane
    • the secretory vesicle's contents are released into the extracellular fluid
  37. Cytoplasm
    • cellular materials outside nucleus but inside plasma membrane
    • composed of 1/2 cytosol and cell organelles
  38. Cytoskeleton
    the infrastructure of the cell made of fibrous proteins, supports the cell and holds the nucleus and other organelles in place, movements and changes in cell shape
  39. Microtubules
    • hollow tubes made of protein units called tubulin
    • are involved in cell division and in transport of intracellular materials
  40. Microfilaments/actin filaments
    • are small fibrils that form bundles, sheets or networks in cytoplasm
    • provide structure to the cytoplasm
  41. Intermediate filaments
    are protein fibers that provide mechanical strength to cells
  42. Cytoplasmic Inclusions
    aggregates of chemical either produced or taken in by the cell
  43. Cell Nucleus
    • the control center of the cell
    • consists of nuclear envelope, nucleolus, and chromatin or chromosome
  44. Nuclear Envelope
    • porous double membrane
    • separates nucleoplasm from cytoplasm
  45. Nucleolus
    • composed RNA and proteins
    • site of ribosome production
  46. Chromatin Or Chromosome
    stores information for synthesis of proteins
  47. Ribosomes
    • Site of protein synthesis
    • composed of a large subunit and a small subunit
    • types= free and fixed/attached
  48. Endoplasmic Reticulum
    • a network of membranous tubules within cytoplasm of a eukaryotic cell continuous with the nuclear membrane
    • consists of broad flattened interconnecting sacs and tubules
    • the interior spaces of those sacs and tubules is called cisternae and are isolated from the rest of the cytoplasm
  49. Rough Endoplasmic Reticulum
    • has attached ribosomes
    • proteins production and modification
  50. Smooth Endoplasmic Reticulum
    • no attached ribosomes
    • manufactures lipids
    • lipids metabolism
  51. Golgi Apparatus
    Composed of Flattened membrane sac stacked on each other
  52. Golgi Apparatus-Function
    • modification, packaging, distribution of protein and lipid for secretion or internal use
    • (the UPS Store)
  53. Organelles-Centrosome
    • composed of microtubules two rod-like centrioles
    • produce cilia, flagella and mitotic fibers to move the chromosomes during cell division
  54. Peroxisomes
    • enzyme-containing sacs
    • break down organic molecules fatty acids and amino acids
  55. Lysosomes
    • membrane bound vesicles that form at the golgi apparatus
    • enzyme containing sacs (garbage disposal)
    • digest worn out cell parts or unwanted substances
  56. Lysosomes Garbage Disposal Steps
    • a vesicle forms around material outside the cell
    • the vesicle is pinched off from the plasma membrane and becomes a separate vesicle inside the cell
    • a lysosome is pinched off the golgi apparatus
    • the lysosome fuses with the vesicle
    • the enzymes from the lysosomes mix with the material in the vesicles, and the enzymes digest the material
  57. Centrioles
    • located in the centrosome found near the nucleus
    • center of microtubules organizing center
    • before cell division centrioles divide, move to ends of cell and organize spindle fibers
  58. Mitochondria
    • power house of the cell- cell generator
    • convert chemical energy to ATP
    • double membranes- Cristae and matrix
    • contains DNA that codes for some of the mitochondrial protein enzymes
  59. Cristae
    • one of mitochondrias membrane
    • infoldings of inner membrane
  60. Matrix
    substance located in space formed by inner membrane
  61. Cilia
    • short appendages projecting from cell surfaces
    • for movement and protection
  62. Flagella
    • similar to cilia but longer and thicker
    • usually only one per cell
    • for movement
    • ex-sperm cell
  63. Cell Metabolism
    • glycolysis=2 ATP in cytosol
    • Citric Acid Cycle and electron transport=26/28 ATP in matrix of mitochondria
  64. Transcription
    RNA synthesis(requires energy) in the nucleus, DNA code is copied to mRNA
  65. Translation
    protein synthesis occur in the cytoplasm, on the ribosomes
  66. DNA Replication
    2 strands of DNA molecule separate; new complementary strand is added using separate piece as a template
  67. The Cell Life Cycle
    • interphase (G1, S, G2 phases)
    • Mitosis
    • Cytokinesis
  68. Interphase
    cell carries out regular metabolic activities (G1) cell increases in size and doubles cell components and DNA (S phase) and the cell prepares to divide (G2)
  69. S phase (synthesis phase)
    the DNA is replicated (new DNA is synthesized)
  70. Mitosis
    the division of a cell's nucleus into two new nuclei each containing the same amount and type of DNA as original nucleus
  71. Prophase
    • chromatin condense to form mitotic chromosomes each consists of two chromatids
    • the centrioles move to the opposite ends of the cell and the nucleolus and nuclear envelope disappear
  72. Metaphase
    the chromosomes align near the center of the cell in association with the spindle fibers
  73. Anaphase
    chromatids separate and each chromatid is then referred to as a chromosome
  74. Telophase
    • nuclear envelopes form around each set of chromosomes to form two separate nuclei
    • the chromosomes begin to uncoil
  75. Cytokinesis
    • cytoplasmic division, separate process from mitosis
    • begins in anaphase and continues through telophase first sign is the formation of a cleavage furrow
  76. Cleavage Furrow
    an indentation of the plasma membrane that forms midway between centrioles
  77. Meiosis
    • cell division for gametes production interphase followed by two cell divisions
    • results in four haploid gametes
    • containing 1/2 of the chromosomes
    • genetically not identical
    • ovum and sperm unite to form a zygote
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Anatomy and Physiology Chapter 3 Cell Biology
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