• Shuffle
    Toggle On
    Toggle Off
  • Alphabetize
    Toggle On
    Toggle Off
  • Front First
    Toggle On
    Toggle Off
  • Both Sides
    Toggle On
    Toggle Off
  • Read
    Toggle On
    Toggle Off
Reading...
Front

Card Range To Study

through

image

Play button

image

Play button

image

Progress

1/47

Click to flip

Use LEFT and RIGHT arrow keys to navigate between flashcards;

Use UP and DOWN arrow keys to flip the card;

H to show hint;

A reads text to speech;

47 Cards in this Set

  • Front
  • Back
Speed of H20

Speed of C6H12O6
2500km/h (1500mi/hr)

850km/h
Flux
Amount of material crossing a surface in a unit of time
Net flux
Difference between two one-way fluxes
Diffusion equilibrium
equal numbers of molecules diffuse in both directions
Three types of fluxes
2 one-way fluxes in opposite directions
Net flux
_____ always proceeds from regions of higher concentration to lower concetration (most important)
Net flux
Magnitude of net flux depends on:
1: temperature (higher temp, highter nf 2: mass-greater mass, lower speed, smaller net flux 3:surface area-greater sa, great nf 4: medium-air easier than h20
Bulk flow
Circulatory system pumps(heart) materials rapidly over large distances
Permeability coefficient
(P) ease w/ which molecule able to move through a membrane
Net Flux equation
J=PA(Co-Ci)

A=surface area
P=permeability coefficient
Co-Constant extracellular concentration
Ci-intracellular concentration
___diffuse slowly or not, ____diffuse rapidly(have large permeability constants
Polar molecules
Nonpolar molecules
Membrane Potential
separation of electrical charge that exists across plasma membranes
Most cells have a _____ charge on the inside
Negative
The direction and magnitude of ion fluxes depend on _____ and _______
concentration difference

electrical difference
Electrochemical gradient
Concentration difference and membrane potential
Channel gating
Process of opening and closing ion channels
Three factors altering channel protein conformations
1: ligand-gated channels
2: Voltage-gated channels
3: Mechanically-gated channels
Ligand-gated channels
specific molecules bind to channel proteins-directly/indirectly allosteric/covalent change in shape
Voltage-gated channels
Changes in membrane potential
Mechanically-gated channels
Physically deforming the membrane
T/F
Membranes can have all 3 kinds of channels
True
Transporters
Nondiffusional movements of iions medicated by integral membrane proteins called:
Process of mediated transport
Solute binds to site on transporter, transporter changes shape-exposes same site to solution on opposite side. sbstance dissociates
Ion Channels
Both
Transporters
Move more ions/unit, continuous flow

membrane proteins & chemical specificity

Must change shape-not as many ions pass
T/F
Proteins that transport amino acids also transport sugars.
False
3 factors determine magnitude of solute flux
1: Extent of saturation
-depends on both solute conc. and affinity for solute
2: # transporters in membrane
3: rate @ which conformational change occurs
2 types of mediated transport
Facilitated diffusion
Active Transport
Facilitated diffusion moves solutes ______ and active transport moves them _____
Downhill

Uphill
Why doesn't glucose concentration in cells become equal to outside with facilitated diffusion?
Once on the inside, glucose is immediately converted to Glucose-6-Phosphate
How does insulin affect glucose transporters?
Insulin increases the # of transporters in membrane
Diabetes melitus
Muscle and adipose tissue can't efficiently import glucose-high ECF glucose
Active Transport
Moves solutes against electrochemical gradient-ATP
Similarities of active and facilitated transport
requires substance binding to transporter.
Specificity and saturation
2 types of energy coupling
1: Primary active transport
2: Secondary active transport
ATPase
catalyzes the breakdown of ATP-phosphorylates itself
Na+/K+ ATPase pump
Sodium out and K in
Na/K pump function
1: Transporter w/ATP binds 3 Na+ ions @ high affinity sites
2: Binding results in activation of ATPase causing phosphorylation, releases ADP.
3: Phosphorylation-change in transporter-Na+ exposed to ECF, reduces affinity-released
4: New conformation increases 2 binding sites for K+ on EC surface
5: K+ binding dephosphorylates transporter-reduces affinity for K+-original conformation-now Na+ can be bound again.
Three other pumps
Ca2+ATPase
H+ATPase
H+/K+ATPase
Ca2+ATPase
In plasma membrane. Ca2+ from cytosol to ECF-why Ca in cells is low-10^-7mol/L
H+ATPase
in plama membrane, inner mitochondrial/lysosomal membranes. H+ATPase moves H out of cells-maitain pH
H+/K+ATPase
In plasma membrane of stomach and kidneys-1H out and 1K+ in/1ATP
Secondary Active Transport
Uses electrochemical gradient as energy source, not phosphorylation-one substances moves down it's gradient and the other uphill.
Transporters that mediate secondary active transport have ____ binding sites one for a/an ____ and another for _____
2
ion
cotransported molecule
Process of Secondary Active transport (Na+)
High affinity sites for sodium on EC surface. Sodium binds, increasing affinity of binding site for transported solute-conformational change, exposing sites to IC side, Sodium detaches to ICF by diffusion down electrochemical gradient, affinity decreases releasing solute
What determines creation and maintenance of electrochemical gradient?
Primary active transporters
Cotransport
Movement in same direction
Countertransport
Movement in opposite directions