Membrane Structure Flashcards
B2.1.1-B2.1.17
True or False? Properly functioning cell membranes are integral to our health.
True
Why is it called the Fluid Mosaic Model?
It shows that all membranes are flexible (fluid), and composed of many different molecules (mosaic)
What is a phospholipid?
The “backbone” of the membrane bilayer composed of glycerol.
two of the glycerol carbons are bound to _____ _____. The other is attached to a highly _____ organic alcohol that bonds to a _________ group.
fatty acids; polar; phosphate
Is a phospholipid hydrophilic, hydrophobic, or amphipathic? Why?
Amphipathic. The heads are polar and the tails are non-polar.
The attraction between _____ is weak so the space between is more _____.
tails; fluid
Fluidity causes varying _____ among cells
Shape
In cellular diffusion how do particles move?
From higher concentrations to lower concentrations
What is the difference between Integral Proteins and Peripheral proteins?
Integral are amphipathic and pass through both parts of bilayer. Peripheral mainly stays on hydrophilic heads and is sometimes attached to the integral protein.
What are the three differences between active and passive transport?
Active moves against concentration gradient, passive moves along. Active requires energy, passive does not. Active does not reach equilibrium, passive does.
What type of transport is Osmosis?
Passive.
Osmosis involves _____ moving across a selectively ________ ________
water; permeable membrane
The amount of water that moves through is determined by the amount of _______ in the cell.
Solute.
Hypotonic vs hypertonic.
Hypotonic= less solute, Hypotonic = more solute.
What are Aquaporins?
They are channels that allow water to move through the bilayer despite water being a polar molecule.
What two proteins are in Facilitated diffusion?
Carrier and channel proteins.
What is the ideal size and charge of a substance that can move through a selectively permeable membrane?
Small and non-polar.
What is a Glycolipid?
it is a carbohydrate chain attached to a phospholipid.
What is a Glycoprotein?
It is a carbohydrate chain attached to a cell membrane protein (integral or peripheral)
Glycomolecules are important for ____ ________.
Cell adhesion.
Where in the bilayer is cholesterol found and what does it do?
it is found in the hydrophobic region and it allows the phospholipids to function at varying temperatures.
Endocytosis and exocytosis allow _____ molecules to move across the membrane
Large.
What is the difference between endocytosis and exocytosis?
Endo is entering exo is exiting.
