Busy. Please wait.

show password
Forgot Password?

Don't have an account?  Sign up 

Username is available taken
show password


Make sure to remember your password. If you forget it there is no way for StudyStack to send you a reset link. You would need to create a new account.
We do not share your email address with others. It is only used to allow you to reset your password. For details read our Privacy Policy and Terms of Service.

Already a StudyStack user? Log In

Reset Password
Enter the associated with your account, and we'll email you a link to reset your password.
Don't know
remaining cards
To flip the current card, click it or press the Spacebar key.  To move the current card to one of the three colored boxes, click on the box.  You may also press the UP ARROW key to move the card to the "Know" box, the DOWN ARROW key to move the card to the "Don't know" box, or the RIGHT ARROW key to move the card to the Remaining box.  You may also click on the card displayed in any of the three boxes to bring that card back to the center.

Pass complete!

"Know" box contains:
Time elapsed:
restart all cards
Embed Code - If you would like this activity on your web page, copy the script below and paste it into your web page.

  Normal Size     Small Size show me how

CH.5 Cell Membranes

Membrane Structure phospholipid bilayer, proteins, carbohydrates
Phospholipids Amphipathic molecules
hydrophobic water fearing, faces in
hydrophilic water loving, faces out
Mosaic Contains lipids, proteins, and carbohydrates
Fluid lipids can move relative to each other within the membrane
Integral Membrane Proteins transmembrane and lipid anchored proteins
Transmembrane proteins regions a physically embedded in the hydrophobic portion of the phospholipid bilayer
lipid-anchored proteins an amino acid of the protein is covalently attached to a iipid
Peripheral Membrane Proteins noncovalently bound either to integral membrane proteins that project out from the membrane, or to polar head groups of phospholipids
Fluidity of Membranes membrane are semifluid and the lipids can rotate freely and laterally
Flip-flp the enzyme flippase requires ATP to transport lipids between sides
Lipid Rafts a group of lipids float together as a unit with a high concentration of cholesterol and a unique set of membrane proteins
Factors affecting fluidity length of fatty acid tails, presence of double bond in the fatty acid tails, presence of cholesterol
Selectively Permeable Membrane only allows passage of some ions and molecules but not others
Importance of Selective Permeability only essential molecules enter the cell, metabolic intermediates remain, and waste products exit the cell
Ways to move across membranes diffusion, facilitated diffusion, and active transport
Diffusion solute diffuses down its gradient, requires no energy, and no transport protein
Facilitated Diffusion solute diffuses down its gradient with the help of a transport protein
Active transport transport protein moves a soute against its gradient and requires energy
Rate of Diffusion Dependent on size, polarity, charge
Necessity of Gradients meant to maintain a constant internal environments that is different from their external environment
Transmembrane Gradient concentration of a solute is higher on one side of the membrane than the other
Ion Electrochemical Gradient both an electrical gradient and chemical gradient
Isotonic equal water and solute concentrations on either side of the membrane
Hypertonic solute concentration is higher on one side of the membrane
hypotonic solute concentration is lower on one side of the membrane
Osmosis Water diffuses to the side with less water
Importance of Osmosis animals must balance extracellular and intracellular solute concentrations to maintain size and shape
Crenation cells in hypertonic medium lose water and shrink
Lysis cells in hypotonic medium gain water and can burst
Turgor in plant cells, a small amount of water may enter the cell, but the cell wall prevents major expansion
How do paramecium survive in strongly hypotonic environments vacuoles take up water and discharge it outside the cell
Transport Proteins transmembrane proteins that provide a passageway for the movement of ions and hydrophilic molecules across membrane
Channel Proteins forms an open passageway that is gated for direct diffusion of ions or molecules across the membrane
Example of Channel Proteins Aguaporins
Transporter Proteins conformational change transports solute across membrane
What organic molecules do transporters uptake? sugars, amino acids, nucleotides
Types of Transporters uniporter, symporter, antiporter
Uniporter transports single ion or molecules
symporter transports two or more ions or molecules in the same directions
antiporter two or more ions or molecules transported in opposite directions
Active Transport movement of solute across a membrane against its gradient from a region of low concentration to higher concentration with the use of energy
Primary Active Transport directly uses energy and a pump to transport a solute
Secondary Active Transport uses another gradient to drive movement through a pump
Na/K ATPase 3 Na are exported out for every 2 K imported into a cell
Intercellular Channels allow the direct movement of substances between adjacent cells
Gap junctions in animal cells it allow ions and small molecules to pass in order to communicate between cells
Plasmodesmata intercellular channel for plants
Created by: noorfarhat4