Biol110 Cell Biology
Spring 2009
Section Quiz #1-1
Questions
1) Why do you need to stain a biological sample (e.g. a cell) prior to visualizing it under
the electron microscope?
a) because you want to add fluorescence for easy visualization
b) because biological materials have little or no contrast under the EM
c) to fix its contents in place
d) to track the mobility of macromolecules within it
2) Are membrane coat proteins…
a) lumenal membrane proteins
b) integral membrane proteins
c) lumenal peripheral membrane proteins
d) cytoplasmic peripheral membrane proteins
3) What are membrane coat proteins mainly used for during vesicle budding?
a) to protect vesicles from proteases
b) to sort proteins into the vesicles
c) to deform membranes
d) to protect the vesicle against the effects of osmosis
e) only two of the above
4) Having two short fatty acid tails makes a lipid molecule
a) cylindrical
b) spherical
c) conical
d) square
5) Velocity sedimentation gradients are used to separate organelles on the basis of
a) size
b) density
c) charge
d) isoelectric point
6) An ion channel usually transports ions:
a) down a concentration gradient
b) against a concentration gradient
c) utilizing energy in the form of ATP hydrolysis
