1. What biochemical feature of a phospholipid molecule allowsphospholipids to spontaneously form closed compartments when placedin an aqueous solution?
a) they are amphipathic
b) they are charged
c) they are spherical
d) they have a single fatty acid tail
2. Other than phospholipids, what molecule do cells use to alterthe fluidity of biological membranes?
3. What distinguishes active transport from passivetransport?
a) active transport can utilize channel proteins
b) passive transport does not utilize carrier/transporterproteins
c) active transport requires the input of energy
d) active transport only occurs at the plasma membrane
4. In the case of active transport, the Na+/K+ pump undergoes asequence of conformational changes that allows the movement of Na+and K+ across a membrane against their electrochemical gradients,while in the case of ER protein import SRP undergoes a sequence ofconformational changes to allow the signal sequence to interactwith the translocation pore. What drives these conformationalchanges?
a) hydrolysis of a high energy phosphate bond
b) binding of a solute or protein
c) both
d) neither
5. Is protein import into the ER co-transcriptional, orco-translational?
