Chapter 2

  1. cell membrane
    regulates the passage of substances into and out of the cell
  2. What molecules make up the cell membrane?
    lipids and proteins
  3. types of lipids
    • phospholipids
    • cholesterol
    • glycolipids
  4. phospholipids
    bilayer with hydrophilic heads on the outside and hydrophobic heads on the inside
  5. amphipatic
    both hydrophilic and hydrophobic
  6. integral proteins
    span the cell membrane and can form channels, transporters, receptors, while others are enzymes
  7. peripheral proteins
    attached to either the outer or inner surface of the cell membrane & form cytoskeletal anchors or act as enzymes
  8. functions of a cell membrane
    • Communication
    • Shape & protection
    • Selective permeability
  9. maintenance of electrochemical gradient
    the cell membrane creates both a chemical and electrical gradient across the membrane
  10. What kind of entities contribute to the development of the electrical gradient across the membrane?
    ions and other charged molecules
  11. simple diffusion
    Movement of molecules from a region of high concentration to an area of low concentration: does not require an input of energy, a cell membrane, or transport/carrier proteins
  12. facilitated diffusion
    Movement of molecules from a region of high concentration to an area of low concentration: does not require an input of energy, but does require transport/carrier proteins in the cell membrane
  13. osmosis
    Movement of water molecules or solvent molecules from a region of high water concentration to an area of low water concentration: does not require an input of energy, does not require pores in the cell membrane
  14. active transport
    Movement of molecules from a region of low concentration to an area of high concentration: does require and input of energy & transport/carrier proteins in the cell membrane
  15. endocytosis
    Transport of large molecules into the cell due to the “engulfing” action of the cell membrane & the subsequent formation of a membrane bound vesicle
  16. Phagocytosis
    “cellular eating” of solid matter
  17. pinocytosis
    “cellular drinking” of predominantly extracellular fluid
  18. Exocytosis
    Reverse of endocytosis - secretory vesicles formed within the cell fuse with the cell membrane, emptying their contents into the extracellular environment
  19. Receptor-mediated endocytosis
    specific pathway in which a molecule must bind to a specific receptor in the cell membrane to initiate an endocytotic event. Once within the cell, the receptors & molecules separate with the receptors returning to the cell membrane, while the specific molecules are processed
  20. cytoplasm
    all cellular contents between the cell membrane & the nucleus - it includes the cytosol, organelles
  21. cytosol
    thick fluid composed of 75% - 90% water with the remaining composed of soluble & insoluble molecules & ions
  22. organelles
    "organs" of cells that have specific functions
  23. nucleus
    • “Control center” of a cell, contains hereditary material (DNA) arranged as genes on chromosomes
    • Surrounded by a double-membrane nuclear envelope which contain nuclear pores to allow the movement of molecules
    • between the cytoplasm & nucleus
    • Contain nucleoli for the assembly of ribosomes necessary for protein synthesis
  24. ribosomes
    • Composed of ribosomal RNA (rRNA) & proteins
    • Sites for protein synthesis
    • May be free-floating in the cytoplasm or bound to endoplasmic reticulum
  25. endoplasmic reticulum
    • Smooth ER is continuous with the nuclear envelope & is involved in Reticulum (ER) lipid metabolism & detoxification
    • Rough ER has ribosomes attached to it & is involved in modification, storage, & transportation on proteins
  26. golgi complex
    • Composed of flattened, stacked sacs called cisternae
    • It processes, sorts, packages, & delivers proteins & lipids to the plasma membrane & forms lysosomes & secretory vesicles
  27. protein route for exocytosis
    ribosomes, RER, transport vesicles, Golgi complex, secretory vesicles, exocytosis
  28. lysosomes
    Contain digestive enzymes

    Digestion includes processes such as autophagy - digestion of organelles & autolysis - digestion of their host cell
  29. peroxisomes
    • Contain oxidizing enzymes, like catalase
    • Detoxification function
  30. mitochondria
    Site for cellular respiration, production of ATP
  31. cytoskeleton
    Cellular shape & movement
  32. flagella
    Long, whip-like structure for movement
  33. cilia
    Short, hair-like structures for movement
  34. centrioles
    Forms the mitotic spindle for cell division & is involved in the formation & regeneration of flagella & cilia
  35. cell cyle
    interphase and mitosis
  36. interphase
    • Composed of G1, S, & G2 phases
    • Growth & preparation for division (mitosis) occur during the G phases
    • DNA replication occurs during the S phase
  37. Mitosis
    Prophase, Metaphase, Anaphase, & Telophase
  38. prophase
    • chromosomal condensation, nuclear envelope
    • disintegration, and spindle formation
  39. metaphase
    “lining up” of the chromatid pairs on the metaphase (equatorial) plate
  40. anaphase
    chromatid separation
  41. telophase
    reverse of prophase
Card Set
Chapter 2
cell structure