Ch. 5 Membranes Flashcards
(51 cards)
Where are phospholipids located?
In the bilayer of the membrane
What’s a fluid mosaic model?
a mosaic of proteins that float in/on the fluid lipid bilayer (like boats on a pond); created in 1972 by S. Johnathan Singer and Garth J. Nicholson
What’re the 4 components of a cellular membrane?
1) Phospholipid bilayer
2) Transmembrane proteins
3) interior protein network
4) Cell-surface markers
What is lipidomics?
the # and biological function of lipids
What are the three classes of lipids?
1) glycerol phospholipids
2) Sterols
3) Sphingolipids
Does an Ampipathic structure have hydrophobic, hydrophilic, or both regions?
Both
What’re the 7 functions of membrane proteins?
1) Transport
2) enzymes
3) cell surface receptors
4) cell surface markers
5) cell to cell adhesion
6) attachment to cytoskeleton
7) proteins that affect the membrane structure
What do anchoring molecules do?
Attach membrane proteins to the membrane surface
What’s passive transport?
the net movement of molecules through the membrane; no energy required
What’s diffusion?
net movement of molecules from high concentration to low concentration
What’s the major barrier for molecules that try to cross the biological membrane?
The interior is hydrophobic
What does facilitated diffusion do?
Assists molecules that can’t cross membranes easily by helping them move through proteins
Are channel proteins hydrophilic or hydrophobic?
Hydrophilic
What does an ion channel do?
Allow passage of ions through the non polar interior of the plasma membrane
What makes gated channels open and close?
Stimuli
What’s Osmosis?
net diffusion of water across a membrane
What is a hypertonic solution equal in terms of concentration?
Higher solute concentration; aka hyperosmotic; cells shrink
What does hypotonic solution equal in terms of concentration?
lower solute concentration; hypoosmotic; cells blow up
What does it mean if a solution is isotonic?
Both osmotic concentrations are equal; cells don’t change
What do aquaporins do?
facilitate osmosis
What is osmotic pressure?
the force needed to stop osmotic flow
What happens to water during extrusion?
it get ejected through contractile vacuoles
How much of sodium is moved out and how much potassium moves in during the Sodium-Potassium pump?
3 Na+ out, 2 K+ in
Does phagocytosis take in matter or fluid only?
matter only
