Reading...
Play button
Play button
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;
30 Cards in this Set
- Front
- Back
|
Functions of membrane carbohydrates
|
Lubrication
Protection Anchoring Locomotion Specificity in binding (receptors) Recognition (immune response) |
|
|
Three general types of transport across cell membrane
|
Diffusion
Mediated Transport Systems Osmosis |
|
|
Concentration - def'n
|
Amount of solute in a solvenrt
|
|
|
Concentration Gradient - desc
|
The difference in the amount of solute when comparing one side of a solution - across a membrane - to the other
|
|
|
Non-polar molecules diffuse through the lipid portions of the membranes more ______ than polar or ionized molecules
|
Non-polar molecules diffuse through the lipid portions of the membranes more _rapidly_ than polar or ionized molecules
|
|
|
Factors affecting diffusion rates:
|
Distance the particle has to move
Molecule size Temperature Gradient Size Electrical forces |
|
|
Two types of diffusion:
|
Simple
Channel-gated |
|
|
Smaller molecule size _______ diffusion rate
|
Smaller molecule size _increases_ diffusion rate
|
|
|
Higher temperature _______ diffusion rate
|
Higher temperature _increases_ diffusion rate
|
|
|
Materials that will diffuse through cell membrane - examples
|
lipid-soluble compounds
dissolved gases |
|
|
Materials that pass through transmembrane proteins (channels) - examples
|
water soluble compounds
ions |
|
|
Channel-mediated diffusion depends on the following criteria of the particle:
|
size
charge interaction with channel |
|
|
Osmosis - def'n
|
The diffusion of water across a cell membrane
|
|
|
The greater the amount of solute, the _____ the concentration of water molecules
|
The greater the amount of solute, the _lower_ the concentration of water molecules
|
|
|
Osmotic Pressure - def'n
|
The force generated by concentration gradient of water
|
|
|
Osmotic Pressure ____ Hydrostatic Pressure
|
Osmotic Pressure _=_ Hydrostatic Pressure
|
|
|
Hydrostatic pressure - def'n
|
The pressure exerted by a fluid at equilibrium due to the force of gravity
|
|
|
Isotonic - def'n
|
A solution that does not cause osmotic flow of water in or out of a cell
|
|
|
Hypotonic - def'n
|
Relatively less concentrate; loses water by osmosis
|
|
|
Hypertonic - def'n
|
Relatively more concentrate; gains water by osmosis
|
|
|
A cell in a hypotonic solution ____ water
|
A cell in a hypotonic solution _gains_ water
|
|
|
A cell in a hypertonic solution ____ water
|
A cell in a hypertonic solution _loses_ water
|
|
|
Types of carrier-mediated transport:
|
Facilitated diffusion
Active transport |
|
|
Characteristics of carrier-mediated transport:
|
Specificity - 1 transport protein, 1 set of substrates
Saturation limits - Rate depends on transport proteins, not substrate Regulation - cofactors such as hormones |
|
|
Cotransport - def'n
|
2 substances move in the same direction at the same time
|
|
|
Countertransport - def'n
|
1 substance moves in while another moves out
|
|
|
Characterists of facilitated diffusion
|
Passive
carrier-mediated |
|
|
Facilitated diffusion - desc
|
Molecule binds to receptor site on carrier protein
Protein changes shape & molecule passes through (Receptor site is specific to certain molecules) |
|
|
An active transport Exchange Pump . . .
|
An active transport Exchange Pump . . . countertransports 2 ions at a time
|
|
|
A sodium-Potassium exchange pump sends _ K+ ions __ and _ Na+ ions ___
|
A sodium-Potassium exchange pump sends _2_ K+ ions _in_ and _3_ Na+ ions _out_
|
