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PHYSIOLOGY - Compartmentation; cells and tissue

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tasnimjaisee's version from 2017-10-12 20:30

Section: Cell membrane part 1

Question Answer
What 2 parts?Anatomical & Functional
Cranial cavityPosterior and Anterior
Abdominopelvic cavityAbdomin and Pelvic
Thoracic CavityPleural sac and Pericardial sac
Parts of ECFBlood Plasma and Interstital fluid
Interstital fluidsSurrounds most cells
Blood plasmaECF fluid inside blood vessels
3 major components of cell membrane• Lipids • Proteins • Carbohydrates
Precardial sacTissue that surrounds the heart
The function of Cell membranes? (4)Physical isolation - Environmental exchange - Cell&environment communication - Structural support
Are all membranes created equal?No
The more metabolically active the membrane is the more _____ it cointainsprotein
3 types of lipids in membranesPhospholipids - Sphingolipids - Cholesterol
Types of membrane phospholipids (3)Bilayers - Micells - Liposomes
Micelles (2)heads outside & tails inside circle - lipid digestion
Liposomesaqueous inside - 1 layer of head near water, 2nd layer is tails with tails of 1st layer and head outwards
Structure of lipids(Ampipathic) - Polar Hydrophilic head & Non-Polar Hydrophobic fatty acid tail
PhospholipidsMajor lipid: hydrophillic heads hydrophobic tail
Cell membrane model is known as?Fluid mosaic model
Fluid Mosaic model (2)Protein spread out - Extracellular surface has glycoproteins & glycolipids
What do Integral proteins include?Transmembranes (TM), lipid anchored proteins (directly to fatty acid, GPI anchor)
GPI anchorsugar phosphate chain
Integral protein Roles (5)Receptors - Adhesion - TM Movement - Enzymes - Mediator IC signaling
Peripheral protein rolesIC signaling - Submembranous cytoskeleton
SphingolipidsLipid rafts: Fatty acid tail, phosphate group or sugar attached
Lipid rafts attract ____ to create ____ and ____Integral proteins - Receptors - Channels
Cholesterol (2)Increases viscosity - decreases permeability (adding flexability)
What happens in air-water enviornment ?Monolayer, head down and tail up
If there is no air-water enviornment what happens?Bilayer forms
2 types of proteins embedded in cell membraneintegral proteins and peripheral proteins
Lipid anchored proteins associate with _____ than _____sphinogolipids - phospholipids
How much more cholestrol are there in sphingolipids?3 to 5x more (viscous)
Cell membrane types in carbohydratesGlycoproteins and Glycolipids
GlycoproteinStructure - Hormone - Immunology - Transport
GlycolipidRecognition sites for cell⟷cell interactions
Lipid raft typesFlotilin and caveolin
How many proteins types does the fluid mosaic model interact with?10-50
Which is longer, phospholipids or sphingolipids?Sphingolipids
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Section: Cell membrane part 2

Question Answer
The ECF and ICF are in ___ equilibrium but have very different ___Osmosis - Chemical composition
Body Fluid compartmentsICF - ECF: Interstital fluid - Blood plasma
Inreacellular fluid is ___ of the total body water volume2/3
How many kg out of 70kg is water?42
Osmotic equilibriumEqual concentration; solute per volume
OsmosisMovement of water across membrane responding to solute concentration gradient
Can water can move between intracellular & extracellular spaces?Yes
Aquaporin channels (2)13 types - Short & long term water regularion
Are solutes equal in each compartment? No, disequalibrium
Osmotic pressureApplied pressure to prevent osmosis
OsmolairtyNumber of particles in solution (individually)
How can osmotic movement of water be predicted?Knowing concentations of each solution
We are interested in ___ ___, not ___ ___osmotically active - entire molecules
IsosmoticEqual
HyperosmoticGreater than
HyposmoticLess than
In terms of T and O: In cell, 3NP - in solution 1NP, 2PHypotonic - Isosmotic
In terms of T and O: In cell, 3NP - in solution 3NP, 2PIsotonic - Hyperosmotic
TonicityQualitative volume changes
Tonicity vs. Osmolarity: MeasureT: No units; comparable term - O: Solute particles dissolved; Measurable
Tonicity vs. Osmolarity: Comparison valuesT: Compare solution⟷cell - O: Compare 2 solutions
Tonicity vs. Osmolarity: Results when placed in solutionT: Explain cell volume - O: Doesn't explain what happens to cell
Tonicity: Cell swells, what happens to solution?Solution is hypotonic
Tonicity: Cell shrinks, what happens to solution?Solution is hypertonic
What crosses cell membranes, depend on? (2)Cell membrane properties (lipid & proteins) and subsistence (size & lipid solubility)
DiffusionHigher concentration to lower concentration
Properties of diffusion (3)Kinetic energy - Continues until equilibrium - 2 part/open systems
Diffusion is fast if.... (4)high CG - high temperature - small molecules - short distances
Rate of simple diffusion is faster if? (4)- Membrane: ↑surface area, thinner, ↑permeability
- ↑concentration gradient
Simple diffusion membrane permeability to molecule depends on molecules' (3)Lipid solubility - Size - Membrane lipid composition
Membrane permeability equationLipid solubility over molecular size (division)
Why can't majority of molecules in the body cross membrane by simple diffusion?Because of being Lipophobic / electrically charged
Types of membrane transportCarrier proteins - Channel proteins
What are channel proteinClusters of different central pores
Types of channel proteins"leak channels" (aquaporrin) - Gated channels
"leak channels" (aquaporrin)Pores are open
Types of gated channelsAlways normally closed: Ligand - Voltage - Mechanically
Carrier proteins qualities (3)Large/Complex - Changes for transports - Slow
Types of protein carrier (3)Uniport, symport, antiport
Symport carriersMoves 2+ sybstrate in same direction
Uniport carriers (2)One type of substrates - In and out
Antiport carriersDifferent substrates - Opposite directions - USES ATP
How do carrier protein work in terms of passage openings?Passage opens to 1 side - Transition state with both gates closed - Passage opens to other side
Small organic molecules that can’t pass through channels, what do they use?Carrier proteins
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Section: Cell membrane part 3

Question Answer
Types of Passive Transportsimple and facilitated diffusion
Glucose example of facilitated diffusionGLT transporters bring glucose down CG - Diffusion equilibrium reached when concentration is same in and out
Facilitated diffusion (2 - concentration gradient & equilibrium)move down concentration gradient; no energy needed - stops when equilibrium reached
Most cells keep intercellular glucose concentrations ___ so diffusion ___ ___ equilibriumlow - doesn't reach
Types of active transportPrimary - Secondary
Primary Active TransportTransport energy comes from hydrolyzing ATPase
Secondary active transportUses potential energy in concentration gradient of 1 molecule to push another molecule against their concentration gradient - Symport
SpecificityOnly move 1 type of molecules
CompetitionCarrier moves 2+ related group substances but they compete
SaturationTransport rate depends on concentration & transporters numbers - Increases with increasing concentration until all transporters are used
Vesicular transport typesPhagocytosis - Endocytosis - Exocytosis
How does endocytosis differ from phagocytosisMembrane indents - Vesicles are smaller
Endocytosis: Non-SelectivePinocytosis - Receptor-mediated transport
Exocytosis stepsMR moves to cell membrane - Transport vesicle and cell membranes fuse - Exocytosis
Caveolae can be used instead ofclathrin coated pits
Which chemical can exocytosis be regulated by?Ca2+
Absorptionfrom lumen of organ to ECF (transcellular)
Secretionfrom ECF to lumen of organ (paracellular)
What is epithelial transportSubstances entering/exiting body cross layer of epithelial cells (line lumen/surface of organs)
Types of epithelial transportTranscellular - Paracellular - Transcytosis
Epithelial transport: TranscellularThrough cell
Epithelial transport: ParacellularThrough tight junction
Epithelial transport: TranscytosisPlasma proteins are concentrated in caveolae - Endocytosis forms vesicle - Viscle crosses cell with cytoskeleton aid - Contents are released in Interstital fluid with endocytosis
Epithelial glucose transportNa+ glucose transporter brings glucose in against gradient with energy stored in Na+ CG - GLUT transporter transfers glucose to ECF - Na+ K+ ATPase makes NA+ out of cell, keeping ICF Na+ concentrations low
How does transport epithelia cells work? (5)Lumen -> apical membrane -> central epithelial cells -> basolateral membrane -> ECF
Pinocytosisallows ECF to enter
Sodium-potassium pumpNa+/K+ ATPase = 3 NA+ out, 2K+ in
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Section: Cell membrane part 4

Question Answer
Apical membraneWith microvilli and faces lumen
Basolateral MembraneFaces ECF
Are transporting epithelia polarized?Yes, it ensures 1-way movement
Cations (+)Intracellular K+ // Extracellular Na+
Anions (-)Intracellular Phosphate ions, proteins // Extracellular Cl
ECF has excess of which charge?Cation (+)
ICF has excess of which charge?Anion (-)
Membrane potential (Vm)Electrical disequilibrium that exists between the ECF and ICF
Electrochemical gradientThe combination of electrical and concentration gradients
As K+ ions leave cell, inside of cell becomes ___ and outside more ___-,+
Equilibrium potentialmembrane potential that exactly opposes the concentration gradient
Resting membrane potentialMembrane potential of a cell when it is not active
Cannot measure absolute electrical charge so we describe electrical gradients on a ___ scaleRelative
The resting membrane potential is due mostly to which chemical?K+
Resting cells are permeable to both of which chemicals?Na+ and K+ but to different degrees (40x more to K+)
Resting membrane potential: Na-K ATPaseElectrogenic pump (generates charge separation) - Maintains concentration gradients for Na+ & K+
Resting membrane potential: 3 Na+ out / 2 K+ inGenerates negative intracellular charge
Two factors influence a cell’s membrane potentialConcentration gradients - permeability
DepolarizationIf membrane potential becomes less negative than resting potential
HyperpolarizationIf membrane potential becomes more negative than resting potential
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