In the absence of tension, MscL channel has an energy gap separating the closed and open states Eo = 50 kT. MscL opening is associated with a 20 nm2 in-plane protein expansion (change in A). Plot its open probability (Po) as a function of membrane tension. What will be the open probabilities of two MscL channels if one situates at the pole of the bacterial cell above, another in the middle?

Ran is a major player in the process of nucleocytoplasmic transport via the nuclear pore. Because net Ran movement simply follows a concentration gradient, what maintains the Ran gradient across the nuclear membrane? Options:   the concentration levels of cargo in the nucleus to be exported   GTP concentrations in the nucleus   the correct positioning of the GEF and GAP with respect to the nuclear envelope   the interaction of exportin and importin with their cognate substrates   none of the above

plant cells with an aqueous potential of -600kPa were placed in different aqueous potentials. Determine in which of the following cases after 10 minutes the cells were blocked, started plasmolysis or completely subjected to the latter. Solution A is -400kPa, solution B is - 600kPa, solution C is -900kPa and solution D is distilled water

. Where are the Ran-GAP and Ran-GEF proteins predominately located?  They are both inside the nucleus They are both outside the nucleus Ran-GAP is on the outside of the nucleus, while Ran-GEF is on the inside of the nucleus RanGAP is on the inside of the nucleus, while RanGEF is on the outside of the nucleus They are both cytosolic (found in the cytoplasm)

As opposed to clathrin vesicles, COP1 vesicles DO NOT bud by a GTP-independent process retrograde transport from the Golgi to the ER More than one answer mediate retrograde transport from the cis-Golgi to the trans Golgi contain a receptor that recognizes mannose-6-phosphate

The movements of single motor-protein moleculescan be analyzed directly. Using polarized laser light, it ispossible to create interference patterns that exert a cen-trally directed force, ranging from zero at the center to afew piconewtons at the periphery (about 200 nm from thecenter). Individual molecules that enter the interferencepattern are rapidly pushed to the center, allowing them tobe captured and moved at the experimenter’s discretion.Using such “optical tweezers,” single kinesin mol-ecules can be positioned on a microtubule that is fixed toa coverslip. Although a single kinesin molecule cannotbe seen optically, it can be tagged with a silica bead andtracked indirectly by following the bead (Figure Q16–3A).In the absence of ATP, the kinesin molecule remains at thecenter of the interference pattern, but with ATP it movestoward the plus end of the microtubule. As kinesin movesalong the microtubule, it encounters the force of the inter-ference pattern, which simulates the load…