Studied by 1 personUnidirectional
________- only operates in one direction.
Saturation
________- substrate concentration at which all binding sites are constantly occupied.
Competition
________- molecules seem to compete for space, but one with greater concentration gradietn will be transported at greater rate.
Simple
not using a protein, molecule can pass between phospholipids or through another medium such as air or water
Cell mediated
using a protein to cross the cell membrane
Passive
driven by concentration gradient, no energy input by cell required for movement, gradient not required
Brownian motion
random movement of particles in liquid or gas, no change in concentration over time
Simple diffusion
movement of molecules from area of high concentration to area of low concentration leading to change in concentration over time
Concentration gradient
difference in concentration between two areas
molarity (M or mM)
concentration of solute in solution, moles/L or millimoles/L
Temperature
average kinetic energy of the sample
Molecular size (dalton, amu)
size of the molecule
Electrochemical gradient
gradient consisting of both charge and concentration
Eq potential
charge gradient equal and opposite to concentration gradient in force
Osmosis
net movement of water across a semi-permeable membrane
Osmolarity (OsM, mOsM)
concentration of active particles in solution in osmoles or millisosmoles
Osmotic gradient
difference in osmolarity across a semipermeable membrane
Osmotic pressure
pressure generated when water pushes toward the side with higher osmolarity in a system with a fixed volume (or the pressure required to prevent osmosis)
Tonicity
describes the effect of a solution on the volume or tension of a cell
Isotonic
no net osmosis, no effect on cell volume or tension
Hypertonic
net osmosis out of cell, decreases cell volume and tension → crenation of cell
Hypotonic
net osmosis into cell, increases cell volume and tension → swell and lyse of cell
Uniporter
moves one type of molecule
Cotransporter
moves more than one type of molecule
Symporter
same direction
Antiporter
oppsite directions to each other
Unidirectional
only operates in one direction
Bidirectional
operates in either direction depending on conditons
Conformational change
change in the 3D shape of a protein
Specificity
specific based on size, shape, charge of substrate
Competition
molecules seem to compete for space, but one with greater concentration gradietn will be transported at greater rate
Saturation
substrate concentration at which all binding sites are constantly occupied
Vmax/Tmax
highest rate of transport possible without adding more proteins, at or above saturation concentration
Facilitated diffusion
passive movement of molecules across a cell membrane from high concentration to low concentration via a transmembrane protein, leading to a change in concentration over time
Primary active transport
movement of molecules across a cell membrane via a transmembrane protein using ATP as the energy source
Secondary active transport
movement of one molecule from low concentration to high concentration coupled with the movement of another molecule from high concentration to low concentration using the concentration gradient of the second molecule as the energy source
What is simple?
not using a protein, molecule can pass between phospholipids or through another medium such as air or water
What is cell mediated?
using a protein to cross the cell membrane
What is passive?
driven by concentration gradient, no energy input by cell required for movement, gradient not required
What is Brownian Motion?
random movement of particles in liquid or gas, no change in concentration over time
What is simple diffusion?
movement of molecules from area of high concentration to area of low concentration leading to cahnge in concentration over time
What is concentration gradient?
difference in concentration between two areas
What is molarity?
cocentration of solute in solution, moles/L or millimoles/L
What is temperature?
average kinetic energy of the sample
What is molecular size?
size of the molecule, measured in dalton or amu
What effects membrane permeability?
thickness, resistance, and surface area of membrane
What is electrochemical gradient?
gradient consisting of both charge and concentration
What is Eq potential?
charge gradient equal and opposite to concentration gradient in force
What is osmosis?
net movement of water across a semi-permeable membrane
What is osmolarity?
cocentration of active particles in solution in osmoles or milliosomoles
True or False: Size and type of particle is important in osmolarity.
False - only requirement is particle is water soluble
How is osmolarity calculated?
molarity X number of particles from each molecule
What is osmotic gradient?
difference in osmolarity across a semipermeable membrane
What is osmotic pressure?
pressure generated when water pushes toward the side with higher osmolarity in a system witha fixed volume (or pressure required to prevent osmosis)
What is tonicity?
describes the effect of a solution on the volume or tension of a cell
What is isotonic?
no net osmosis, no effect on cell volume or tension
What is hypertonic?
net osmosis out of cell, decreases cell volume and tension causing crenation of cell
What is hypotonic?
net osmosis into cell, increases cell volume and tension causing cell to swell and eventually lyse
What are examples of transport proteins?
transporters, channels, ATP powered pumps
What is a uniporter?
moves one type of molecule
What is a cotransporter?
moves more than one type of molecule
What is a symporter?
moves more than one type of molecule in same direction
What is an antiporter?
moves more than one type of molecule in opposite directions to each other
What is unidirectional?
only operates in one direction
What is bidirectional?
operates in either direction depending on conditions
What is conformational change?
change in the 3D shape of a protein
What is specificity?
specific based on size, shape, charge of substrate
What is competition?
molecules seem to compete for space, but one with greater concentration gradient will be transported at greater rate
What is saturation?
substrate concentration at which all binding sites are constantly occupied
What is Vmax/Tmax?
highest rate of transport possible without adding more proteins, at or above saturation concentration
What is facilitated diffusion?
passive movement of molecules across a cell membrane from high concentration to low concentration via a transmembrane protein, leading to a change in concentration over time
Binding of a substrate causes what to occur during facilitated diffusion?
conformational change
What is primary active transport?
movement of molecules across a cell membrane via a transmembrane protein using ATP as the energy source
What causes conformational change in primary active transport?
phosphorylation & dephosphorylation
Na+/K+ pump is an example of what type of transport?
primary active; moves 3 Na+ out, 2 K+ in, and uses 1 ATP
What is secondary active transport?
movement of one molecule from low concentration to high concentration coupled with the movement of another molecule from high concentration to low concentration using the concentration gradient of the second molecule as the energy source
Ca2+/Na+ antiporter is an example of what transport?
secondary active transport; 1 Na+ in and 1 Ca2+ out
Note
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