Term
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Definition
| all cells have a plasma membrane made of a phospholipid bilayer with various other embedded and assoicated molecules |
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Term
| Forces that act on particles |
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Definition
chemical
Electrical
Electrochemical (or net electrochemical) |
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Term
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Definition
a force that acts to push particles down their concentration gradient (high to low)
random motion of particles
acts on each kind of particle independently |
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Term
| If K+ ions are more concentrated in side a cell than outside which direction is the chemical force acting on K+ |
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Definition
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Term
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Definition
| this force arises when the inside and outside of a cell have different concentrations of ositive and negative charges |
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Term
| If the inside of a cell has more negative charges than the outside the membrane voltage (Vm) is |
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Definition
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Term
| If the inside of a cell has more positive charges that the outside, we say that the membrane voltage (Vm) is |
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Definition
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Term
| If the inside and outside of the cell have equal numbers of positive and negative charges, we say the membrane voltage is |
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Definition
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Term
| Do neutral charges feed electrical forces |
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Definition
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Term
| Positively charged particles feel a force towards the more |
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Definition
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Term
| Negatively charged particles feel a force towards the more |
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Definition
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Term
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Definition
| is the sum of teh electrical and chemical forces |
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Term
| What are the three passive transports |
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Definition
Diffusion through the phospholipid bilayer
Facilitated diffusion
Diffusion through channels |
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Term
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Definition
| particles always go dwon their electrochemical gradient (in the direction of the net electrocheical force) |
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Term
| Diffusion through the phospholipid bilayer |
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Definition
requires no energy expenditure by the cell
a carrier protein undergoes a conformational change, to flip the particle to the other side of the membrane |
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Term
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Definition
| can transport up to 10,000 glucose molecuse per second |
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Term
| Diffusion through channels |
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Definition
Requires no energy expenditure by the cell
Channels are like pores they allow particles to flow in either direction |
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Term
| What are the two types of channels |
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Definition
Water channels
Ion channels |
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Term
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Definition
| also called aquaporins - allow only water to pass through - do not allow solutes to pass through |
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Term
| Water channels are especially important in what two systems |
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Definition
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Term
| Water channels net movement of water is always in what direction |
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Definition
| down the concentration gradient (from area of lower osmolarity to area of higher osmolarity) |
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Term
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Definition
for ions only ( and a little water that goes with them) net movement of ions through channels is down the electrochemical gradient of that ion |
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Term
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Definition
Requires energy
moves molecules agianst their net electrochemical gradient |
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Term
| What are the two types of Active transport |
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Definition
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Term
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Definition
proteins
use ATP to move particles agianst their gradient
show preference to bind a particle on one particular side and release it on the other |
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Term
| Examples of primary active transport |
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Definition
| calcium pumps in muscle cells H+/K+ pumps in the lining of stomach, which make the stomach contents acidic |
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Term
| Secondary active transport |
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Definition
harness energy released by the passive transport of one kind of particle, to drive active transport of another kind of particle
EX: Sodium-linked glucose transport |
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Term
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Definition
a vesicle buds off towardthe inside of the cell, bringing in whatever contents are trapped inside
EX: white blood cells engulfing bacteria |
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Term
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Definition
A vescile fuses with the membrane, releasing contents outside
EX: Neurotransmitter release |
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Term
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Definition
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Term
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Definition
| is the measure of solute concentration in water |
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Term
| Will water flow from an area of lower osmolarity to an area of higher osmolarity |
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Definition
Yes - lower solute concentration or more dilute
or "higher water concentration" to higher solute concentration,
or less dilute, or "lower water concentration" |
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Term
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Definition
| Diffusion of water across a membrane |
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Term
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Definition
| refers to whethr a solution causes a cell placed in it to shrink or swell. Is determined by the relative concentrations of impermeant solutes only, in the solution and the ICF |
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Term
| If transport of molecules across a membrane requires energy is this active transport or passive transport |
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Definition
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Term
| The movement of a molecule into or out of the cell by its own thermal motion is called what |
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Definition
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Term
| Active transport is always mediated by transport proteins referred to as |
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Definition
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Term
| The energy of solution depends on |
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Definition
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Term
| Do solutes move passively from an area where they are in greater concentration to an area where they are in lesser concentration |
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Definition
| Yes - they move down their concentration gradient which requires an input of energy |
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Term
| What are the three types of driving forces |
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Definition
chemical
energy
electrochemical |
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Term
| We refer to a concentration gradient as a _______________ the direction of which is always down the concentation gradient |
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Definition
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Term
| ions are are influenced by type of driving force |
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Definition
| electrical- postive and negative charges |
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Term
| What two two driving forces influence ions during transportation |
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Definition
1) a chemical force reflecting the ions' tendency to move down their concentration gradient (from higher to lower)
2) an electrical force reflecting the ions' tendency to be pushed in one direction or the other by the membrane potential |
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Term
| The total force acting on the ions is the combination of chemical and electrical driving forces, referred to as |
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Definition
| electrochemical driving force |
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Term
| If a chemical reaction is neither forward nor backward what is this called |
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Definition
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Term
| What types of passive transport are there |
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Definition
simple diffusion
facilitated diffusion
diffusion through ion channels |
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Term
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Definition
| passive transport through membrane's lipid bilayer |
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Term
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Definition
| the movment of molecules from one location to another |
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Term
| When a substance is transported passively across a membrane by simple diffusion, the rate at which it is transported depends on three factors |
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Definition
the magnitude of the driving force
the membrane surface area
the permeability of the membrane |
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Term
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Definition
| the transfer of thermal energy from one object to another that occurs when the obects are in direct contact with each other in the nervouse system the progagation of action potentials along an axon |
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Term
| In simple diffusion, do individual molecules always go down their concentration gradient |
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Definition
| Yes - because they are in a state of constant thermal motion |
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Term
| In simple diffusion the rate of transport is directly related to what |
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Definition
| the size of the driving force |
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Term
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Definition
is a transmembrane protein that binds molecules on one side of membrane and transports them to the other side by means of conformational change, or change in shape |
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Term
| Carrier in facilitated diffusion |
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Definition
| a transmembrane protein that binds molecules on one side of a membrane and transports them to the other side by means of a conformational change, or a change it shape |
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Term
| What type of substances are transported by carriers |
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Definition
| monosaccharides and amino acids |
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Term
| The rate of facilitated diffusion is determined entirely by three factors |
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Definition
1) the transport rate of individual carriers
2) the number of carriers in the membrane
3) the magnitude of the concentration grandient of the transported substance |
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Term
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Definition
| is a transmembrane protein that transports molecules via a passageway or pore that extends from one side of the membrane to the other |
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Term
| What are two types of channels |
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Definition
| water channels (aquaporins) and ion channels |
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Term
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Definition
| the transport of two substances in the same direction |
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Term
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Definition
| the transport of two substances in opposite directions |
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