Biology Questions here!?

Question

I have two biology questions here:

1) The cells of plant seeds store oils in the form of droplets enclosed by membranes. Unlike the membranes you studied in this chapter, the oil droplet membrane probably consists of a single layer of phospholipids rather than a bilayer. Draw a model for a membrane around an oil droplet, and explain why this arrangement is more stable than a bilayer.

2) An experiment is designed to study the mechanism of sucrose uptake by plant cells. Cells are immersed in a sucrose solution, and the pH of the surrounding solution is monitored with a pH meter. The measurements show that sucrose uptake by the plant cells raises the pH of the surrounding solution. The magnitude of the pH change is proportional to the starting concentration of sucrose in the extracellular solution. A metabolic poison that blocks the ability of the cells to regenerate ATP also inhibits the pH changees in the surrounding solution. Propose a hypothesis accounting for these results. Suggest an additional experiment to test your hypothesis.

So, guys, please help me out with those two questions!!!!!!

Answer 1

Don't Be a Dead weight. Do them yourself. those are actually easy if you know the material

Answer 2

1.) A good example is soap, oil, and water. When you clean your dishes, you might have oil on your plate. Well you grab the soap and use water. The interaction of these compounds forms a single layer of phospholipids. The water is on the outside and the oil is inside. Understand the structure of the phospholipid and you will get your answer for why it is stable.

Answer:

http://members.aol.com/fromscience/exper...

2.)

Ok in order to understand this what is going on in this experiment, you need to write down everything that occurs and understand why it occurs.

a.) "Cells are immersed in a sucrose solution, and the pH of the surrounding solution is monitored with a pH meter. The measurements show that sucrose uptake by the plant cells raises the pH of the surrounding solution."

----> We know what happens initially. When cells are put into a sucrose solution, pH raises (making it basic), by removing/absorbing sucrose from the solution.  

b.)  "A metabolic poison that blocks the ability of the cells to regenerate ATP also inhibits the pH changees in the surrounding solution."

-----> So when this poison is addd to the cells or produced by them, they do not produce ATP and hence inhibits changes in the pH of the solution.

c.) "The magnitude of the pH change is proportional to the starting concentration of sucrose in the extracellular solution."

-----> This is a simple observation that the change in pH = concentration of sucrose in solution. This fact is important to an extent, we just care about the cells.

So look at points a and b. You see that in a, when cells absorb sucrose, the pH becomes more basic. Then in b, the pH does not change when this poison is introduced to the cells via itself or added to the solution. I would say to itself. Now we have a simple relationship, which is poison = no pH change = no sucrose uptake = no ATP production. This implies that the cells need sucrose to make ATP. But the question said a poison was introduced, so you can say that this poison was actually an inhibitor of the ATP production pathway, which prevents the cells from absorbing up sucrose from the solution. Because the ATP production stopped means that there is no need for sucrose uptake.

I would design an experiment to test for ATP production in the cells. I would make 4-5 samples of sucrose solutions, which increase by a certain factor and see if ATP production is increased or decreased by the amount of sucrose. Testing for amount of ATP. Also I would test the same thing for pH. I should also see a linear change within the increasing solution samples.

good luck.