Science MCAT

The flashcards below were created by user jmali921 on FreezingBlue Flashcards.

  1. thickness of cell membrane
    10 nm
  2. most eukaryotic cells are between ____ and ___ in diameter
    10um and 100um
  3. resolution is dependant on;
    is calculated as 1/2 of ______
  4. 2 types of phospholipids in the cell membrane
    • glycerophospholipids
    • sphingolipids
  5. glycerophospholipids is composed of
    • glycerol linked to
    • 2 fatty acyl groups and one phosphate group
  6. 1 um = ________ A
  7. 1A = ____ um
  8. this lipid absent is most prokaryotes
  9. addition of this molecule to the membrane bilayer reduces fluidity of lipids and penetration of small ions
  10. how is membrane fluidity increased?
    substitution of cis-unsaturated fatty acids for saturated fatty acids
  11. all proteins in the prokaryotic cell is made up by _________
    free ribosomes
  12. In a prokaryotic membrane (like a chloroplast in a plant cell)
    this cell contains photosynthetic pigments
  13. the plama membrane of a prokaryotic cell lacks _________________, which is typically found in eukaryotic cells
    cholesterol and glycolipids
  14. the ratio 2:1 in chromatin represents
    weight (2 protein : 1 DNA)
  15. histone ratio wieght to DNA (eukaryotes)
  16. lenth of a nucleosome (in base pairs)
    • 2 turns
    • 146 basepairs
  17. largest functional compartment in eukaryotic cells
  18. glycolysis occurs in which compartment?
  19. proteins that will function in the nucleus are made on?
    free ribosomes
  20. golgi bodies are called _____ in plant cells
  21. lysosomal enzymes are recognized from its signal sequence in the Golgi. It is tagged with ______________________
    mannose-6-phosphate residues
  22. Location on the Krebs cycle?
    matrix in the mitochondria
  23. These are very elongated microvilli
    found in the ducts of the epididymis
  24. Mesenchymal cells
    (cells in connective tissue)
    • undifferemtiated cells which could become any other connective tissue
    • primarily found in embryonic and fetal tissues
    • capable of moving
    • smaller than fibroblasts
  25. Fibroblasts
    (cells in connective tissue)
    • largest # of cells present in connective tissue
    • active state: flattened, oval nucleus, basophilic cytoplasm
    • Inactive state: appear as elongated spindles, elongated nucleus
  26. Reticular Fibers
    • Thinner than collagen
    • arraned in intermeshing network, supports organ
    • inelastic
    • walls of blood vessels, lymphoid tissues, red bone marrow, basal laminae, glands of liver and kidney
  27. adipocytes
    (cells in connective tissue)
    • found in most connective tissue
    • singly or in groups
    • do NOT undergoe mitosis
  28. Mast cells
    (cells in connective tissue)
    • ovoid cells with small round nuclei
    • cytoplasm has numerous basophilic granules (stain)
    • granules composed of:
    • Histamine - dialates blood vessels, increases permability.
    • Heparin - anticoagulant

    • take part in allergic response
    • numerous in repiratory tract and near small blood vessels
  29. what is Heparin
    • heparin is an anticoagulant
    • released from mast cells
  30. The axoneme
    The structure is the core axial structure in cilia and flagella
  31. Periodic acid schiff staining

    (PAS stain)
    detects presence of glycogen granules which are not visible by LM, but can be demonstrated by LM with this stain
  32. The outerface of the plasmamembrane (euk) is enriched in _________________
  33. Define
    Occuluding junction
    regions where the outer layer of the plasma membranes of associated cells appear fused (no extracellular space)
  34. In eukaryotes, a 45S precursor rRNA is cut into 3 large ribosomal subunits
    • 5.8s
    • 18s
    • 28s
  35. Zonula Occludens
    This cell-cell junction prevents passage of materials through the extracellular space between cells and allow the epitheium to serve as a barrier
  36. simple squamous epithelium
    • endothelium of:
    • blood and lymphatic vessles
    • bowmans capsule
    • thin loop of henle
    • lung aveoli
    • smallest excretory ducts of the glands

    Function: lubrication of body cavities
  37. Simple cuboidal epithelium
    • kidney tubules
    • choroid plexus
    • thyroid gland
    • rete testis
    • surface of ovary

    Function: Secretion, absorption, lines surface
  38. Stratified Cubiodal Epithelium
    • ducts of sweat glands
    • developing follicles of ovary

    Function: secretion, protection
  39. stratified squamous keratinized epithelium
    • epidermis of skin
    • prevents water loss; protection
  40. Stratified squamous non-keratinized epithelium (moist)
    • Mucousa of:
    • oral cavity
    • esophagus
    • anal canal
    • vagina
    • cornea of eye
    • conjunctiva

    Function: secretion, protection, prevent water loss
  41. This receptor is involved with the initial binding of neutrophils to endothelial cells as the neutrophils leave blood bessels during inflammatory reactions
    P-selectin receptors (bind to glycocalyx oligosaccharides in the plasma membrane
  42. define: communicating junction
    • allows ions to move from cytoplasm of one cell to another cell
    • usually contains protein channels that cross both membranes
  43. 4 things a plant cells lacks which is present in an animal cell
    • Nucleiod
    • centrioles
    • cilia and flagella
    • microvilli
  44. In microscopy, describe the fixation process of dehydration
    water is usually removed from tissues by passing in through a series of increasing strengths of alchohol solutions
  45. simple columar epithelium
    • cells lining lumen of digestive tract
    • gall bladder
    • many glands
    • uterus
    • uterine tube (ciliated)

    function: secretion, absorption, protection, lubrication
  46. pseudostratified columnar epithelium
    • lines lumen of respiratory tract
    • ducts of epididymus (stereocilia)
    • ductus of deferens
    • male urethra

    function: secretion, protection, facilitates transport of substances on surfaces of cells
  47. Stratified columnar epithelium
    • male urethra
    • conjuctiva

    fucntion: protection
  48. Transitional epithelium
    Urinary Tract

    function: protection
  49. Ground substance
    • a component of connective tissue
    • located btw cells and fibers; both embedded in ot
    • intercellular material
    • when fresh, looks transparent
    • route for passage of nutrients and wastes to and from cells within or adjacent to connective tissues

    • composed of:
    • glycoaminoglycans (chondroitin sulfate and hyaluronic acid)
  50. Elastic Fibers
    • yellow fibers, refractile fibers
    • thinner than collagen
    • walls of blood vessels, true vocal cords, and trachea
  51. Collagen Fibers
    • White Fibers
    • most numerous fibers type in all tissue types in varying amount
    • strong and resist stetching

    tendons, ligaments, aponeuroses, and fascia
  52. Peroxisomes
    these membrane-lined vesicles contain catalase;

    catalase generates hydrogen peroxide used to detoxify organic molecules
  53. Connective tissue develops from the
  54. all connective tissue consists of 3 distinct components
    • ground substance
    • cells
    • fibers
  55. Macrophages (hisiocytes)
    • fixed or free cells
    • fixed cells are very numerous in loose connective tissue
    • polymorphic in shape
    • oval nucleus
    • ability to engulf extracellular material
    • difficult to distinguish except during phagocytosis
  56. plasma cells

    (cells in connective tissue)
    • eccentric nucleus
    • chromatin in pattern (spoke wheel appearance)
    • found in lamina propira, GI tract
    • secrete:
    • antibodies, immunoglobulins (IgG) into circulating blood to kill off bacterial invasions
  57. Reticular cells
    (cells in connective tissue)
    • star-shaped cells
    • join processes to form cellular network
    • found in abutting reticular fibers in certain glands and lymphoid tissues
  58. Pericytes
    (cells in connective tissue)
    • located in adventitia (outer layer) of blood vessels
    • can differentiate into various connective tissue cells as well as smooth muscle cells
  59. Peroxisomes are involved in 3 cellular processes
    • Beta oxidation of fatty acis
    • photorespiration
    • glyoxylate cycle in plant cells
  60. the cross section of this organelle in TEM is identified by
    "nine doublets plus 2"
    Cilia and flagella (eukaryotes)
  61. Microvilli contain only ______ and cytosol and have an outer covering of plasma membrane
  62. Kingdom Fungi
    • multicellular w/ membrane bound nuclei
    • absorb nutrients
    • mushrooms, molds
  63. Kingdom Protista
    • unicellular, membrane bound nuclei
    • ingest, absorb, or produce nutrients via photosynthesis
    • protozoans, algea
  64. Kingdom Monera
    • no organized nuclei, unicellular
    • absorb or produce nutrients
    • bacterua, blue-green algae
  65. Kindgom Plantae
    • multicellular with membrane bound nuclei and cell wall
    • possess chlorophyll and undergoe photosynthesis
    • flowering plants and trees; evergreens
  66. Kingdom Animalia
    • Multicellular with membrane bound nuclei
    • ingest nutrients
    • mammals, birds, amphibians, fish, reptiles, insects, crustaceans, etc.
  67. Living things are seperated into the 5 kingdoms based on 3 things
    • presence of absence of membrane bound nuclei
    • the number of cells forming the organism
    • the mechanism for nutrition
Card Set
Science MCAT
Show Answers