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You have two beakers as depicted below.  Both are split in the middle and contain a semipermeable membrane. Both also contain a solute which cannot cross the semipermeable membrane by itself; the amount of solute is different on both sides of the beaker. Beaker #2 contains transporters embedded in the semi-permeable membrane that will allow the solute to pass.    You leave the beakers this way for a few hours and then come back to observe the results. What is most likely to happen?  

SA2a.  (2 pts) In the graph, do the wild-type yeast cell membranes show an increase or a decrease in fluidity with increasing temperature?  Discuss whether this is the result you would expect to see or whether it’s surprising.

This drug acts as both a stimulant and a psychedelic.  It produces an energizing effect that distorts both physical nad coginitive sensations and it may impair memory. It works by affecting a neuron’ ability to use the chemical serotonin.  It can sometimes result in too much water in the blood which can cause brain swelling.  

In the context of protein trafficking, what are  zip codes and signal sequences?

Academic Integrity Statement: I hereby declare that this exam represents my own work. I did not cheat on this exam or help others to cheat on this exam.  I did not share my answers or give help or suggestions to anyone. If I observed any cheating, I will report it to the instructor later today.  

The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than the cytoplasmic phosphate concentration. Phosphate import depends on a pH gradient across the membrane—more acidic outside the cell than inside the cell. Phosphate transport is an example of _____.

Palade’s famous experiment showed the movement of radiolabeled proteins through pancreatic cells.  The order that these proteins traveled was best described as which of the following:

B. (4 pts) What basic role do G Proteins play in cell signaling?

2. (5 pts) Indicate how each alteration would affect membrane fluidity: Alteration Membrane Fluidity will . . . Increasing the amount of phospholipids with unsaturated fatty acyl tails [increasedecrease1] Increasing the length of the phospholipid fatty acyl tails [increasedecrease2] Increasing the temperature [increasedecrease3] Adding cholesterol to a membrane experiencing cold temperatures [increasedecrease4] Adding cholesterol to a membrane experiencing hot temperatures [increasedecrease5]  

What type of signaling involves extremely short-range signals that are carried by vesicles and then dumped into a gap or cleft before being received by a neighboring cell?