Chapter 3 (Cellular Level of Organization)

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Chapter 3 (Cellular Level of Organization)
2014-09-22 13:18:11
Anatomy Physiology

Chapter 3 (Cellular Level of Organization)
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  1. Describe cell theory?
    Cells are the building blocks of all plants and animals. All new cells come from the division of pre-existing cells. Cells are the smallest structural units that carry out all vital physiological functions.
  2. What is differentiation?
    Is the gradual appearance of characteristic cellular specialization during development as the result of gene activation or repression.
  3. What is extracellular fluid?
    All body fluids other than that contained within cells; includes plasma and interstitial fluid.
  4. What is intracellular fluid?
    Is the fluid in the tissues that fills the spaces between cells.
  5. What is cytoplasm?
    The material between the plasma membrane and the nuclear membrane; cell contents.
  6. What is the cytosol?
    The fluid portion of the cytoplasm.
  7. What are organelles?
    Organelles (little organs) are intracellular structures suspended within the cytosol with specific functions or group of functions.
  8. What is the function of peroxisome?
    Breakdown of organic compounds; neutralization of toxic compounds generated in the process.
  9. What is the function of the lysosome?
    Breakdown of organic compounds and damaged organelles or pathogens.
  10. What is the function of microvilli?
    Increase surface area to facilitate absorption of extracellular materials.
  11. What is the function of golgi apparatus?
    Stores, alters, and packages synthesized products.
  12. What is the function of the nucleus?
    Controls metabolism, stores and processes genetic information, controls protein synthesis.
  13. What is the function of endoplasmic reticulum (ER)?
    Synthesis of secretory products; intracellular storage and transport; detoxification of drugs or toxins.
  14. What is the function of ribosomes?
    Protein synthesis.
  15. What is the function of mitochondrion?
    Produces 95% of ATP required by the cell.
  16. What is the function of cytoskeleton?
    Strengthens and supports cell, aids in movement of cellular structures and materials.
  17. What is the difference between smooth ER and rough ER?
    Smooth ER has no attached ribosomes, synthesizes lipids and carbohydrates. Rough ER has ribosomes bound to the membranes, modifies and packages newly synthesized proteins.
  18. What are the general functions of the plasma membrane?
    Physical isolation, regulation of exchange with the environment, sensitivity to the environment and structural support.
  19. What is the plasma membrane?
    Plasma membrane (cell membrane) is a physical barrier that separates the cell contents, or cytoplasm, from the extracellular fluid. Selectively permeable barrier that controls the entry of ions and nutrients; the elimination of wastes and release of secretions.
  20. What is the phospholipid bilayer?
    Is a two-layered arrangement of phosphate and lipid molecules that form a cell membrane, the hydrophobic (tails) lipid ends facing inwards and the hydrophilic (heads) phosphate ends facing outward.
  21. What is the difference between hydrophilic and hydrophobic?
    Hydrophilic are molecules that do readily interact with water and hydrophobic are molecules that do not readily interact with water.
  22. What are peripheral proteins?
    Are bound to the inner or outer surface if the membrane and (like post-it notes) are easily separate from it.
  23. What are integral proteins?
    Greatly outnumber peripheral proteins, which may have regulatory or enzymatic functions. Integral proteins are part of the membrane structure and cannot be removed without damaging or destroying the membrane.
  24. What are transmembrane proteins?
    Span from one side of a membrane though to the other side of the membrane.
  25. What is the function of anchoring proteins?
    Attach the plasma membrane to other structures and stabilize its positon. Inside the cell, membrane proteins are bound to the cytoskeleton, a network of supporting filaments in the cytoplasm.
  26. What is the function of recognition proteins?
    Are detected by cells of the immune system.
  27. What are the function of enzymes?
    In plasma membranes may be integral or peripheral proteins.
  28. What is the function of receptor proteins?
    Bind to a specific extracellular molecules called ligands. A ligand can be anything from a small ion like calcium to large complex hormone like insulin.
  29. What is the function of carrier proteins?
    Bind solutes and transport them across the plasma membrane.
  30. What are the functions of channels?
    Are integral protein containing a central pore that forms a passageway completely though the plasma membrane, The channel permits the passage of water and small solutes that cannot otherwise cross the lipid bilayer of the plasma membrane.
  31. What are microtubules?
    Microtubules are the largest components of the cytoskeleton. They extend outward into the periphery of the cell from a region near the nucleus called the centrosome.
  32. What are intermediate filaments?
    Are the strongest and most durable in cytoskeletal elements. 
  33. What are microfilaments?
    Are the smallest if the cytoskeletal elements. Typically these microfilaments are composed of the protein actin. They are common in the periphery of the cell, but relatively rare in the region immediately surrounding the nucleus.
  34. What is the centrosome?
    Is a region of cytoplasm that contains a pair of centrioles oriented at right angles to one another.
  35. What is the centrioles?
    A cylindrical intracellular organelle composed of nine groups of microtubules, three in each group, functions in mitosis or meiosis by organizing the microtubules of the spindle apparatus.
  36. What is the cilia?
    Are long slender extensions of the plasma membrane.
  37. What is the flagella?
    Thy have the same microtubule structure as motile cilia, but are much longer and beat in a wavelike fashion. The only human cell with a flagellum is a sperm cell.
  38. What is cisternae?
    The endoplasmic reticulum (ER, is a network of intracellular membranes continuous with the nuclear envelope that surrounds the nucleus) forms hallow tubes flattened sheets and chambers called Cisternae.
  39. What is nucleoplasm?
    Is the fluid, gel-like substances of the nucleus. It contains the nuclear matrix, a network of fine filaments that provides structural support and may be involved in regulating genetic activity.
  40. What is nuclear pores?
    Are passageways that permit chemical communication between the nucleus and the cytosol. Proteins at the pores regulate the movement of ions and small molecules and neitherproteins nor DNA can freely cross the nuclear envelope.
  41. What is the nuclear envelope?
    Surrounds the nucleus and separates it from the cytoplasm, is a double membrane.
  42. What are chromosomes?
    Dense structures, composed of tightly coiled DNA strands and associated histones, that become visible in the nucleus when a cell prepares to undergo mitosis or meiosis.
  43. What are chromatin?
    A histological term referring to the grainy material visible in the cell nuclei during interphase; the appearance of the DNA content of the nucleus when the chromosomes are uncoiled.
  44. What is the genetic code?
    The chemical language the cell uses.
  45. What is a gene?
    Is the functional unit of heredity. It contains all the DNA nucleotides needed to produce specific proteins.
  46. What are the five nitrogenous bases and how do they match up?
    Adenine (A), thymine (T), cysteine (C), guanine (G), and uracil (U). Guanine (G) matches up with cysteine (C). Adenine (A) matches up with thymine (T). In messenger mRNA Adenine (A) matches up with uracil (U).
  47. What is a triplet code?
    Is another name for the genetic code, because a sequence of three nitrogenous bases, or triplet.
  48. What is a codon?
    A sequence of three nitrogenous bases along an mRNA strand that will specify the location of a single amino acid in a peptide chain.
  49. What is a anticodon?
    A sequence of three nucleotides forming a unit of genetic code in a transfer RNA molecule, corresponding to a complementary codon in messenger RNA.
  50. What is messenger RNA?
    Is RNA formed at transcription to direct protein synthesis in the cytoplasm.
  51. What is transfer RNA?
    RNA consisting of folded molecules that transport amino acids from the cytoplasm of a cell to a ribosome.
  52. Summarize the process of protein synthesis?
    The DNA triplets determine the sequence of mRNA codons. Then the mRNA codons determine the sequence of tRNAs. Then the sequence of tRNAs determine the sequence of amino acids in the polypeptide or protein.
  53. What is transcription?
    The encoding of genetic instructions on a strand of mRNA.
  54. What is translation?
    The process of peptide formation from the instructions carried by an mRNA strand.
  55. What is a DNA template strand?
    Is the DNA strand that will be used to synthesize RNA.
  56. Name the four steps of translation?
    • 1. Initiation
    • 2. Initiation complex
    • 3. Elongation
    • 4. Termination
  57. What are freely permeable membranes?
    Allows any substance to pass without difficulty. No living cell has a freely permeable plasma membrane.
  58. What are selectively permeable membranes?
    Permit the passage of some materials and prevent the passage of others.
  59. What are impermeable membranes?
    Nothing can pass through impermeable membranes.
  60. What is active transport?
    Active processes require ATP.
  61. What is passive process?
    Does not require ATP.
  62. What is diffusion?
    Is passive molecular movement from an area of higher concentration to an area of lower concentrations.
  63. What is concentration gradient?
    Is the Regional differences in the concentration of a partial substance.
  64. What is Fick's law?
    Diffusion constant times surface area times temperature times concentration gradient divided by molecular weight times molecular thickness.
  65. What is osmosis?
    Is the movement of water across a selectively permeable membrane to form one solution to another solution that contains a higher solute concentration.
  66. What is osmotic pressure?
    Is the force of osmotic water movement; the pressure that must be applied to prevent osmosis across a membrane.
  67. What is osmolality?
    Is the total concentration of dissolved materials in a solution, regardless of their specific identities expressed in moles; also called osmotic concentration.
  68. What is tonicity?
    The effects of various osmotic solutions on cells.
  69. What is hypotonic?
    A solution one that causes osmotic water flow into the cell. The cell may eventually burst releasing its contents this is hemolysis.
  70. What is hypertonic?
    A solution that results in the osmotic movement of water out of the cell. The shrinking of red blood cells is called crenation.
  71. What is isotonic?
    A solution that does not cause an osmotic flow of water into or out of cell is called isotonic.
  72. What is a normal saline solution?
    In clinical of emergencies the fluid often administered is a 0.9 solution of sodium chloride. This isotonic is called normal saline.
  73. What is a cotransport?
    Some carrier proteins simultaneously move more than one substance the same direction.
  74. What is countertransport?
    If a carrier protein simultaneously move two substances in opposite directions.
  75. What is facilitated diffusion?
    Is the passive movement of a substance across a plasma membrane by means of a protein carrier.
  76. How do ion pumps work?
    Actively transport the cations sodium, potassium, calcium and magnesium across their plasma membranes.
  77. What is secondary active transport?
    The transport mechanism itself does not require energy from ATP; but the cell often needs to expend ATP at a later time to preserve homeostasis.
  78. What are vesicles?
    Small membranous sacs that form at or fuse with the plasma membrane.
  79. Describe vesicular transport?
    Materials move into or out of the cell.
  80. What is receptor-mediated endocytosis (transport)?
    Is a small vesicle form at the plasma membrane surface. Many important substances like cholesterol and iron ions are distributed throughout the body attached to special transport proteins.
  81. What is endocytosis?
    Is the importing of extracellular substances through the formation of vesicles at the cell surface. These vesicles are known as endosomes.
  82. What is exocytosis?
    Is the functional opposite of endocytosis. In exocytosis, a vesicle formed inside the cell fuses with and becomes part of the plasma membrane. When this tales places the vesicle contents are released into the extracellular environment.
  83. What is pinocytosis?
    (Cell drinking) is the introduction of fluids into the cytoplasm by enclosing them in membranous vesicles at the cell surface.
  84. What is phagocytosis?
    (Cell eating) is the engulfing of extracellular materials or pathogens; the movement of extracellular materials into the cytoplasm by enclosure in a membranous vesicle.
  85. What is transcytosis?
    The process by which various macromolecules are transported across the interior of a cell.
  86. What is meiosis?
    (Produces sex cells and contain 23 chromosomes) is cell division that produces gametes with half the normal somatic chromosome number.
  87. What is mitosis?
    Mitosis is the division of a single cell nucleus that produces two identical daughter cells (each containing complete set of 46 chromosomes) nuclei; and essential step in cell division.
  88. What is apoptosis?
    Many cells self-destruct after a certain period of time as a result of activation of specific “suicide genes” in the nucleus.
  89. What is interphase?
    Is the period in which the cell is performing normal functions and not actively engaged in cell division. Some cells are interphase indefinitely. Others will always either dividing or preparing to divide.
  90. What is cytokinesis?
    Cell division ends; the divisor of the cytoplasm, physically separates the two daughter cells (daughter cells are genetically identical cells produces by somatic cell division; eventually each daughter cell will grow to size of the original).
  91. What are somatic cells?
    Spend most of their functional lives in a state known as interphase (not actively engaged in cell division; performs all its normal functions and if necessary prepares for cell division).
  92. Explain the G1 phase?
    Normal cell functions plus cell growth, organelle duplication, protein synthesis lasts 8 or more hours.
  93. Explain the G2 phase?
    Protein synthesis; when DNA replication ends there is a brief 2-5 hour period G2 phase is devoted to last-minute protein synthesis and to completing centriole replication.
  94. Explain S phase?
    DNA replication synthesis; this takes 6-8 hours the cell then duplicates its chromosomes. This involves DNA replication and the synthesis of histones and other proteins in the nucleus.
  95. What are the five stages of mitosis?
    • 1. Prophase
    • 2. Metaphase
    • 3. Anaphase
    • 4. Telophase
    • 5. Cytokinesis
  96. What is prophase?
    Begins when the chromosomes coil so tightly that they become visible as individual structures under a light microscope. (The initial phase of mitosis;characterized by the appearance of chromosomes the breakdown of the nuclear membrane and the formation of spindle apparatus).
  97. What is metaphase?
    Begins as the chromatids move to a narrow central zone called the metaphase plate. Metaphase ends when all the chromatids are aligned in the plane of the metaphase plate. (The stage of mitosis in which the chromosomes line up along the equatorial plane of the cell).
  98. What is anaphase?
    Begins when the centromere of each chromatid pair splits and the chromatids separate. The chromatids are now pulled along the spindle fibers toward opposite sides of the dividing cell. (The Mitotic stage in which the aired chromatids separate and move toward opposite end of the spindle apparatus).
  99. What is telophase?
    • Each new cell prepares to return to interphase the nuclear envelopes re-form the nuclei enlarge and the chromosomes gradually uncoil to the chromatin state. This stage marks the end of mitosis.
    • (The final stage of mitosis characterized by the disappearance of the spindle apparatus, thereappearance of the nuclear membrane the disappearance of the chromosomes and the completion of cytokinesis).
  100. What is benign tumor?
    (Tumors are abnormal cell growth) benign tumors are not malignant and the cells usually remain within the originating tissue. Such tumor seldom threatens a person’s life and usually can be removed surgically if its size or position disturbs tissue function.
  101. What is a malignant tumor?
    Malignant tumor divide very rapidly, releasing chemicals that stimulate the growth of blood vessels into the area. The availability of additional nutrients accelerates tumor growth; malignant cells then migrate into surrounding tissues and nearby blood vessels. Cancerous.