Biol-1406 Exam 2 (Campbell Biology
Ch.5-7)
Amphipathic - correct answer Having hydrophilic and hydrophobic regions; phospholipids are this
Overton (Overton's Rule) - correct answer The more lipophilic the molecule, the faster it will diffuse into
cell (thus cell membrane has lipid areas)
Langmuir - correct answer Phospholipids have polar heads and nonpolar tails ("Langmuir's lemurs have
tails")
Gorter & Grendel - correct answer Membranes have a phospholipid BILAYER ("the two Gs found two
layers")
Davson & Danielli - correct answer Sandwich Model of Membrane - layer of protein over phospholipid
membrane ("Davson and Danielli Deli")
Singer & Nicolson - correct answer Fluid Mosaic Model - proteins are embedded into phospholipid layer
("I'd give a nickel for a song about this mosaic model")
What is the fluidity of a membrane controlled by? (2) - correct answer -Fatty Acid (lipid) concentration
-Cholesterol (prevents excess fluidity at high temp and excess viscosity at low temp)
Scanning Electron Microscope (SEM) - correct answer Used to study topography of a specimen, 3-D
image
Transmission Electron Microscope (TEM) - correct answer Used to study internal structure of cells, thin
layer of stained specimen is viewed
