BIO CELL 370 E2 C4 P1

Card Set Information

Author:
shockwave
ID:
140360
Filename:
BIO CELL 370 E2 C4 P1
Updated:
2012-03-22 14:14:01
Tags:
BIO CELL 370 E2 C4 P1
Folders:

Description:
BIO CELL 370 E2 C4 P1 GSU 2012
Show Answers:

Home > Flashcards > Print Preview

The flashcards below were created by user shockwave on FreezingBlue Flashcards. What would you like to do?


  1. NAME THE 7 FUNCTIONS OF A THE MEMBRANE
    • COMPARTMENTALIZATION
    • SCAFFOLD FOR BIOCHM ACTIVITIES
    • SELECTIVLY PERMEABLE MEMBRANE
    • TRANSPORT SOLUTES
    • RESPOND TO EXTERNAL SIGNALS
    • INTERCELLULAR INTERACTION
    • ENERGY TRANSDUCTION
  2. FORMS CONTINUOUS SHEETS THAT ENCLOSE INTRACELLULAR COMPARTMENTS; ENTIRE CELL, NUCLEUS, ORGANELLES & VESSICLES.

    WHAT MEMBRANE MEDIATED FUNCTION?
    COMPARTMENTALIZATION
  3. ALLOWS FOR REGULATED EXCHANGE OF SUBSTANCES BETWEEN COMPARTMENTS, LIKE A MOAT AROUND A CASTLE WITH GATED BRIDGES.

    WHAT MEMBRANE MEDIATED FUNCTION?
    SELECTIVE BARRIER
  4. WHAT MEMBRANE MEDIATED FUNCTION?

    MEMBRANE PROTEINS
    FACILITATE THE MOVEMENT OF SUBSTANCES BETWEEN COMPARTMENTS AND ALLOW FOR ACCUMULATION OF METABOLIC FUELS, BUILDING BLOCKS AND IONS.
    • TRANSPORTING SOLUTES.
    • THINK GRADIENT LEVELS
    • (PROTONS)
  5. Membrane receptors transduce signals from outside the cell in response to specific ligands.

    WHAT Membrane Mediated Function?
    RESPONDING TO EXTERNAL SIGNALS
  6. Membranes mediate recognition and interaction with adjacent cells to exchange materials and information.

    WHAT Membrane Mediated Function?
    INTRACELLULAR INTERACTIONS.
  7. Membranes provide scaffolding.
    Organizes enzymes for effective interaction and orientation.

    WHAT MEMBRANE FUNCTION?
    LOCUS OF BIOCHM ACTIVITIES
  8. -Membranes transduce photosynthetic energy
    -Convert chemical energy to ATP
    -Store energy
    ion gradients
    solute gradients
    WHAT MEMBRANE FUNCTION?
    ENERGY TRANSDUCTION
  9. Dissolving power matched oil using partition coefficients and the speed at which molecules penetrated the membrane.

    MEMBRANE MOSTLY LIPIDS.

    WHO, WHEN & WHERE?
    ERNST OVERTON 1890 IN ZURICH.
  10. WHY CAN IT BE SAID THAT THE MEMBRANE IS IN THE MOST FAVORABLE ENERGETICALLY FAVORABLE ORIENTATION?
    POLAR HEAD GROUPS FACE THE AQUEOUS COMPARTMENTS.
  11. THE LIPID BILAYER WAS DISCOVERED BY WHO AND WHEN?
    • DUTCHMEN, GORTER & GRENDEL
    • 1925
  12. THE MEMBRANE BILAYER IS DEFORMABLE, IT CAN FACILITATES SPLITTING AND FUSION.
    HOW?
    DUE TO THE COHESION. IT FORMS A CONTINUOUS SHEET.
  13. NATURE AND IMPORTANCE OF THE BILAYER MEMBRANE. NAME 3 POINTS.
    • COMPOSITION. DETERMINES PHYSICAL STATE
    • COHESION. CONTINUOUS SHEET.
    • AMPHIPATHIC LIPIDS, SPONTANEOUSLY FORM VESICLES (LIPOSOMES).
  14. ______ ________ SPONTANEOUSLY FORM LIPOSOMES (VESICLES) ARTIFICAL SYSTEMS.
    AMPHIPATHIC LIPIDS
  15. T OR F
    LIPIDS CAN FORM SPOTANEOUSLY?
    • TRUE
    • May have provided first stable environment for self replication
  16. WHO DISCOVERED HOW THE MOVEMENT OF POLAR SOLUTES AND IONS CROSS MEMBRANES AND HOW IS IT DONE?
    • PROTEIN LINED PORES IN MEMBRANE.
    • DAVSON-DANIELLI MODEL 1934 REVISED IN 1954
  17. Fluid-mosaic model is “_____ ______” of membrane biology.
    WHAT DOES IT MEAN?
    • Central Dogma
    • Core lipid bilayerexists in a fluid state
    • Capable of dynamic movement AND FORM MSAISC PATTERN.
  18. THE PORES THAT GO THRU THE MEMBRANE, ARE THEY POLAR OR NON POLAR?
    • HYDROPHILLIC
  19. LIPIDS AND PROTEINS COMPONETS OF THE MEMBRANE ARE BOUND TOGTHER HOW?
    • NON-COLVALENT FORCES.
    • HYDROPHOBIC
    • VAN DER WAALS
  20. T OR F ?
    Protein/lipid ratios vary among membrane types
    TRUE
  21. NAME AN EXAMPLE OF A LOW PROTEIN/LIPID MEMBRANE TYPE.
    Myelin Sheath of Nerve Cell Axon
  22. NAME THE 3 MAIN TYPES OF MEMBRANE LIPIDS Q
    • Phosphoglycerides
    • Sphingolipids
    • Cholesterol
  23. WHAT TYPE OF MEMBRANE:
    -Diacylglycerides with small functional head groups linked to glycerol backbone
    -phosphate ester bonds
    Phosphoglycerides
  24. WHAT TYPE OF MEMBRANE:
    Ceramides formed by attachment of sphingosine to fatty acids
    Sphingolipids
  25. WHAT TYPE OF MEMBRANE:
    Smaller, less amphipathic (animals only).
    DIFFERENT THAT THE OTHER 2 TYPES.
    CHOLESTEROL
  26. WHO AM I?
    Phosphoglycerides
  27. WHO AM I?
    Cardiolipin
  28. WHO AM I?
    Sphingolipids
  29. THIS PARTICULAR MEMBRANE TYPE HAS AA IN IT
    Sphingolipids
  30. IS CHOLESTEROL POLAR OR NON POLAR?
    HOW IS IT DISTRIBUTES IN EACH LEVEL?
    • NON-POLAR
    • EVEN DISTRIBUTED.
  31. THE HEAD OF A MEMBRAINE LIPID IS HYDROPHOBIC OR HYDROPHILLIC?
    HYDROPHILLIC. WATER LOVING. OUTTER SIDE OF CELL AND FACES THE CYTOPLAMSA.
  32. T OR F ?
    CAN EMEBRANE LIPIDS ASSEMBLE SPONTANEOUSLY IN WATER.
    TRUE
  33. T OR F ?
    MEMBRANES GIVE THE CELL THE ABLILITY TO FUSE, FORM NETWORKS AND SEPERATE CHARGES
    TRUE
  34. MEMBRANE CARBOHYDRATES ARE LINKED TO LIPIDS & PROTEINS HOW & WHERE?
    Covalently linked to lipids and proteins on extracellular (OUTSIDE) side of the bilayer.
  35. "INTRA-" MEANS WHAT?
    INSIDE OF
  36. "extracellular" MEANS WHAT?
    • OUTSIDE OF CELL.
    • This space is usually taken to be outside the plasma membranes, and occupied by fluid.
  37. Liposome Vesicle WERE MENTIONED IN THE TEXT.
    HOW BIG AND WHAT DID THEY CARRY?
    • 40-100 nm liposomes
    • Contain anticancer drug doxorubicin
    • High concentrations of drug in insoluble gel fiber
  38. Contains Hydrophilic molecule polyethylene glycol on outer leaflet protect it against immune system...WHAT ARE THEY CALLED?
    • STEALTH LIPOSOMES.
  39. WHAT DO STEALTH LIPOSOMES POSSES THAT PROCTECT THEM AGAINST THE IMMUNE SYSTEM?
    Contains Hydrophilic molecule polyethylene glycol on outer leaflet protect it against immune system
  40. HOW DOES THE STEALTH LIPOSOMES WORK?
    • -Hydrophilic molecule polyethylene glycol on outer leaflet protect it against immune system
    • -Antibodies target it to special tissue receptors
    • -Drugs in various compartments based on solubility
    • -MATCHES TARGET CELL RECIEPTORS--> DRUG DELIEVERED, DISEASE GONE.
  41. polyethylene glycol OR ANY TYPE OF PHOSPHOGLYCERIDES HEAD.
    HYDROPHOBILC OR HYDROPHILIC?
    HYDROPHILIC
  42. Phosphoglycerides: Diacylglycerides with small functional head groups linked to glycerol backbone, WHAT TYPE OF BOND BETWEEN THE HEAD & BACKBONE?
    • phosphate ester bonds.
  43. WHAT THE HELL IS AN ESTER BOND?
  44. T OR F?
    Inner and outer membrane leaflets have different lipids?
    • TRUE.
    • DISCOVERED USING LIPASES WITH ACCESS TO OUTER LEAF ONLY.
  45. membrane leaflets have different physical and chemical properties..WHY?
    Properties appropriate for different interactions at two membrane faces
  46. T OR F ?
    Membrane lipids move easily within a leaflet BUT Rarely “flip-flop” between leaflets.
    TRUE
  47. WHAT IS THE FUNCTION OF FLIPASES?
    • -Actively move phospholipids from one leaflet to another
    • -May be used to establish asymmetry
  48. WHAT ARE Amphipathic molecules?
    Amphipathic molecules have two ends. A Hydrophilic end or a polar end, and a hydrophobic end or a non-polar end. Amphipathic molecules are extremely important in the human body. because they function as transporters of hydrophobic material in the hydrophilic environment of the body. A simple example is that lipids (fat) can not circulate the body along with blood unless it is bonded to an amphipathis molecule or else lipids will not be able to move in the vessels and will make obstructions.
  49. WHAT IS THE FUNCTION AND COMPOSITION OF GLYCOPROTEINS?
    • Have short, branched carbohydrates
    • Interactions with other cells and structures outside cells
  50. NAME THE 2 TYPES OF GLYCOLIPIDS AND THEIR COMPOSITION.
    • Cerebrocide = simple sugar + lipid
    • Ganglioside = oligosaccharide + lipid
  51. Cerebrocide = _______ _______ + lipid
    Ganglioside = _________ + lipid
    • Cerebrocide = simple sugar + lipid
    • Ganglioside = oligosaccharide + lipid
  52. GLYCOLIPDS STRUCTURE, FUNCTION & TYPES.
    • Have larger carbohydrate chains
    • Used as cell to cell recognition sites
    • Cerebrocide = simple sugar + lipid
    • Ganglioside = oligosaccharide + lipid
  53. Have larger carbohydrate chains:
    GLYCOPROTEINS OR GLYCOLIPIDS?
    GLYCOLIPIDS
  54. NAME 2 Amphipathic Molecules
    Glycoproteins & Glycolipids
  55. _________ linkages in ________ are commonly found attached to ___________
    N-glycosidic linkages in N-Acetylglucosamine are commonly found attached to membrane
  56. ___________ linkages found between ______ & _______ in N-galactosamine are less common
    O-glycosidic linkages found between serine and threonine in N-galactosamine are less common
  57. Linkages between sugars and polypeptides, WHAT IS THE MORE COMMON TYPE?
    N-glycosidic linkages in N-Acetylglucosamine are commonly found attached to membrane.

    O-glycosidic linkages ARE LESS COMMON
  58. DEFINE Blood Group Antigens. WHAT ARE THEY COMPOSED OF AND HOW?
    • Short chain of sugars linked to RBC membrane lipids act as blood type determinants
    • Attached oligosaccharides form gangliosides
    • AB blood would have both A and B antigen components
  59. Short chain of sugars linked to RBC membrane lipids act as blood type determinants...ALSO KNOWN AS WHAT?
    • ANTIGENS.
    • FORM BLOOD GROUPS.
    • O,A,B
    • AB blood would have both A and B antigen components
  60. DEFINE AMPHIPATHIC
    • (1) Pertains to a molecule containing both polar (water-soluble) and nonpolar (not water-soluble) portions in its structure.
    • (2) Of, or relating to, a molecule having hydrophobic and hydrophilic regions.
    • EX:DETERGENT OR ALPHA HELIX
  61. NAME THE 2 TYPES OF INTEGRAL AMPHIPATIC MEMBRANE PROTEINS AND THEIR LOCATIONS.
    • Amphipathic transmembrane proteins:
    • Hydrophobic domains anchors them into bilayer
    • Hydrophilic regions form functional domains outside the bilayer
  62. WHAT ARE Amphipathic transmembrane proteins AND HOW ARE THEY CLASSIFIED?
    COMMONLY KNOWN AS INTEGRAL PROTEINS AND Classified as monotopic, bitopic or polytopic based on # of times they span membrane
  63. T OR F ?
    Integral membrane proteins contain one or more transmembrane helices?
    TRUE
  64. Attached to the membrane via weak NONCOLVALENT bonds - easily solubilized.
    Exit entirely outside of the lipid bilayer on either side of membrane.
    Peripheral proteins
  65. Found on the outer leafletCan be released by inositol-specific phospholipases
    Glycophosphotidyl inositol (GPI)-linked proteins
  66. Inner leaflet proteins are anchored to membrane lipids by long hydrocarbon chains. WHAT?
    Glycophosphotidyl inositol (GPI)-linked proteins
  67. _________anchored membrane proteins are distinguished by both types of _______ anchor and their orientation
    LIPID
  68. NAME A TYPE OF LIPID ANCHORED MEMBRANE PROTEIN
    Glycophosphotidyl inositol (GPI)-linked proteins
  69. NAME 3 TYPES OF MEMBRANE PROTEINS
    • INTEGRAL (AMPHIPATHIC)
    • PERIPHERAL (WEAK BONDS, EASILY SOLUBILIZE)
    • LIPID ANCHORED (GPI)
  70. Noncovelantly linked to polar headgroups or lipids or integral membrane proteins...WHO AM I?
    • Peripheral Proteins.
  71. WHAT THE HELL ARE THESE?
  72. Located outside membrane on either side
    These have covalent linkages to lipids in the bilayer
    WHAT ARE THEY?
    Lipid Anchored Proteins
  73. AN EXAMPLE OF THIS PROTEIN WOULD BE phosphotidyl inositol linked to N-acetylglucosamine, manose and ethanolamine
    • Lipid Anchored Proteins.
    • THINK GPI
  74. WHAT THE HELL ARE THESE?
  75. HOW WOULD ONE ANALYZE THE DISTRIBUTION OF PROTEINS IN A MEMBRANE? 2 WAYS.
    freeze fracture and freeze etching
  76. Allows integral proteins to be visualized
    See both proteins on internal and external leaflet
    Membrane associated particles
    “Pebbles on road” look
    WHAT TYPE OF ANALYSIS?
    Freeze fracture replication
  77. NAME THE 2 FRACTURE FACES IN FREEZE FRACTING.
    • particulate face and surrounding ice
    • Particles are about 8 nm in diameter
  78. WHAT Techniques allow the ability to investigate microheterogeneity.
    EXAMPLE: Zipper row in sperm cell or other localized differences
    Freeze fracture replication
  79. REVIEW YOU R GROUP TYPES!!!!!
  80. BASIC FREEZE FRACTURE PROCESS
    • Erythrocyte surface frozen,
    • fractured,
    • then thawed,
    • fixed and labeled with marker.
  81. Triton X-100 used to solubilize membrane protein with intact structure.
    WHAT TYPE OF DETERGENT IS IT AND WHAT SOLUTION DOES IT WORK IN?
    NONIONIC DETERGENT AND WORKS IN A AQUEOUS SOLUTION.
  82. BESDIES FREEZE FRACTURE NAME ANOTHER TECINQUE THAT ID'S PROTEINS.
    • X-ray Crystallography.
  83. WHAT THE HELL IS THIS?
    Glycophorin A Monotopic Integral Membrane Protein with single transmembrane domain
  84. T OR F ?
    WHEN Predicting Transmembrane Insertion, Orientation determined using non-penetrating agents (label protein).
    TRUE
  85. Predicting Transmembrane Insertion.
    NAME THE TWO MAIN POINTS.
    • ORIENTATION
    • determined using non-penetrating agents (label protein).
    • ID
    • transmembrane domains predicted from AA sequence
    • ( Usually contain nonpolar AA in ALPHA-helices)
  86. Channel proteins have _______ cores
    Form ________ channels in membrane spanning region
    • hydrophilic
    • aqueous
  87. WHAT WOULD ONE USE A HYDROPATHY PLOT FOR?
    ID of transmembrane domains
  88. _____________ is measured as free energy required to transfer each segment of polypeptide from non-polar solvent to aqueous solution
    Hydrophobicity
  89. NAME THE PLOT.
    STRETCHES ABOVE ZERO MEAN WHAT?
    STRETCHES ABOVE THE RED LINE MEAN WHAT?
    Hydropathy Plot for Glycophorin A Single Span Protein.

    Stretches above 0 line are energy requiring AAs with non-polar R groups.

    Above red line indicates region of transmembrane domain.
  90. WHAT METHOD IS USED TO show conformational changes in bacterial K+ ion channel.
    • Electron Paramagnetic resonance (EPR) spectroscopy.
  91. Lipids exist in solid or liquid phases depending on conditions. NAME THEM
    • Temperature
    • Lipid composition and saturation
    • Presence of cholesterol
  92. Saturated fats tend to be ______ at RT
    SOLID
  93. Unsaturated fats tend to be_________ at RT
    LIQUID
  94. ________C membranes are relatively fluid
    Two-dimensional liquid crystal
    37C
  95. Importance of membrane fluidity.
    NAME 2 POINTS
    • 1.Compromise between structural rigidity and complete fluidity
    • 2. Membrane fluidity allows for:
    • -Protein migration
    • -Membrane assembly and growth
  96. WHAT TEMPS ARE THESE AT?
    • (a) the lipids are in a configuration above the transition temperature (37C)with relatively free hydrophobic tail movementIn (b) the lipids are experiencing temperatures below the transition state where movement is restricted.
    • The bilayer in b is in a crystaline gel form.
  97. WITH THE MELTING POINTS OF 18 CARBON FATTY ACIDS, THE LESS CIS-DOUBLE BONDS MEANS WHAT?
    • HIGHER MELTING POINT.
  98. T OR F?
    Organisms (not birds and mammals) maintain membrane fluidity as temperature changes
    • TRUE.
    • THEY ALTER THE COMPOSITION OF LIPIDS.
  99. Remodeling lipid layers involves WHAT 3 STEPS?
    • 1. Saturation of acyl chains
    • 2. Desaturation of acyl chains
    • 3. Replacement of acyl chains (Via lipases or transferases)
  100. IN Maintaining Membrane Fluidity, THE IMPORTANCE OF THIS MECHANISM WAS VERIFIED HOW?
    • Verified using mutants unable to carry out certain desaturation reactions.
    • Occurs in response to cold.
  101. Atomic Force Microscope MEASURES WHAT?
    MOLECULAR HEIGHT
  102. Lipid Rafts Atomic Force Microscope ARE MAINLY COMPOSED OF WHAT?
    • Sphingomyelin molecules organize into orange rafts.
    • Yellow peaks show GPI-anchored protein (rafts only).
  103. SRC KINASE EFFECTS WHAT ELEMENT?
    • PHOSPHATE.
    • THINK CELL SIGNALING.
  104. NAME THE RATES OF Phospholipids in Membrane and Between Leaflets.
    • FLEX IS FASTEST, LATERIAL THEN TRANS.
  105. polyethylene glycol IS ALSO KNOWN AS WHAT?
    ANTI-FREEZE INGREDIENT
  106. NAME 2 METHODS TO TRACK PROTEINS DIFFUSION RATE.
    • Fluorescence recovery after photo-bleaching (FRAP)
    • Single particle tracking (SPT)
  107. T OR F?
    Protein movements in membranes are slower than predicted
    Does not work based on size and membrane viscosity alone
    TRUE
  108. Protein movements are limited by interactions with.... NAME 3
    • Cytoskeleton
    • Other proteins
    • Extracellular materials
  109. Patterns of Movement of Integral Membrane Proteins.
    NAME THEM
    • Protein A diffuses randomly, but slowly
    • B is immobilized by interaction with the underlying membrane skeleton
    • C is moved directionally by motor protein
    • D is restricted by other integral proteins
    • E is restricted by fences of membrane proteins
    • F is restrained by extra-cellular materials
  110. Differential Functions of the plasma membrane of an epithelial cell. NAME 3
  111. Highly homogenous preparations of membrane “ghosts” can be prepared inexpensively and simply from RBCs via ______ _____.
    osmotic lysis
  112. T OR F ?
    Membrane proteins can be purified and characterized by fractionation
    • TRUE
    • THINK SDS PAGE ELECTROPHORESIS. SEPERATES BY MW.
  113. _____ _ is a homodimetric, polytopic glycoprotein that exchanges Cl- and HCO3- across the RBC membrane
    Spans the membrane several times
    CO2 leaves via the lungs
    Band 3
  114. ____________ _is a monotopic protein with 16 oligosaccharide chains with negative charges
    Spans the membrane once
    May prevent RBC from clumping
    Charges on cells repel each other
    Receptors for protozoan that causes malaria
    No Glycophorin A - immune to malaria
    Glycophorin A
  115. IF YOU HAVE NO No Glycophorin A, WHAT DISEASE ARE YOU IMMUINE TO AND WHY?
    • No Glycophorin A - immune to malaria.
    • Receptors for protozoan that causes malaria
  116. Major component of internal membrane skeleton of RBC is _______.
    • spectrin
    • A Fibrous protein
  117. Spectrin molecules are attached to the membrane surface.
    WHO'S MEMBRANE SURFACE?
    WHAT AND HOW IS IT ATTACHED?
    • Bound noncovalently to ankyrin
    • Peripheral membrane protein noncovalently bound to band 3

    REMEMBER THAT IT ALSO IS IN THE CYTOPLASM!!
  118. Spectrin is linked to cytoplasmic proteins.
    NAME THEM AND ITS FUNCTION.
    • Actin and tropomyosin
    • This maintains the integrity of the membrane.

    REMEMBER THAT IT ALSO ATTACHES TO THE MEMBRANE!
  119. __________ ________ allows for separation and exchange of materials across membranes
    Selective permeability
  120. ______ ______ is the difference between influx and efflux of materials. WHAT IS THIS CAUSED BY?
    • Net flux
    • CAUSED BY SELECTIVE PERMEABILITY.
    • (INCLUDES PASSIVE DIFFUSION & ACTIVE TRANSPORT)
  121. Flux can occur by WHAT 2 MODES?
    passive diffusion and/or active transport
  122. Diffusion is the spontaneous movement of material from a region of high concentration to a region of low concentration.
    NAME THE 2 FACTORS
    • FREE E CHANGE.
    • 2 FACTORS OF CONCENTRATION AND ELECTROCHEMICAL GRADIENTS.
  123. Four basic mechanisms for solute movement across membranes.
    NAME THEM.
  124. Lipid permeability is determined BY WHAT 3 FACTORS?
    • partition coefficient,
    • molecular size,
    • polarity
  125. Diffusion requires both a _____ ______ & _______ _______.
    concentration gradient and membrane permeability
  126. Plasmolysis.
    OCCURS IN WHAT TYPE OF SOLUTION?
    • hypertonic solutions.
    • CELL SHRINKS
  127. OSMOSIS IS THE DIFFUSION OF WATER. IN PLANTS THE WALLS PREVENT SWELLING.
    WHAT IS THIS KNOWN AS ?
    TURGOR PRESSURE.
  128. Super-families of ion channels have been discovered.
    NAME 4 METHODS USED TO DISCOVER THEM.
    • Cloning
    • Analysis of protein sequences
    • Site directed mutagenesis
    • Patch clamping experiments
    • (Microelectrode measures conductance across membrane)
  129. Ions cross membranes through ion channels.
    NAME THE 2 WAYS.
    • Selective and bidirectional
    • Allows for diffusion in the direction of the electrochemical gradient (of conductance)
  130. NAME THE 2 TYPES OF ION GATE CHANNELS
    • Voltage-gated
    • Conformational state depends on the difference in ionic charge on the two sides of the membrane
    • Ligand-gated
    • Conformational state depends on the binding of a specific molecule (the ligand), which is usually not the solute that passes through the channel
  131. Conformational states of voltage gated K+ ion channel.
    NAME THEM
  132. Voltage gated potassium channel contains _____ membrane-spanning helices
    6
  133. WHAT FORMS THE BALL OR PLUNGERS?
    • N-terminus forms a flexible ball or plug; can block channel
    • S4 transmembrane helix is voltage sensitive
  134. Large amounts of _________ substances require facilitation to cross membranes
    hydrophilic
  135. ________diffusion is passive, specific, saturable and regulated
    Facilitated diffusion
  136. The gradient for glucose entry into the cell is maintained by WHAT FACTORS?
    • phosphorylation of glucose in the cytoplasm.
    • Insulin stimulates glucose uptake.
    • (Causes the insertion into the cell membrane of vesicles containing preformed glucose transporters)
  137. DEFINE TYPES I & II DIABETES
    • Type I diabetes is due to lack of insulin
    • Type II is due to lack of a response to insulin

What would you like to do?

Home > Flashcards > Print Preview