Physio Ex 9.0 Exercise 1

Activity 1
1. Describe two variables that affect the rate of diffusion.
a. There are alot of different variables or factors that can affect the rate of diffusion, for example: size of the molecule, shape of the molecule, concentration gradient, charge of the ions, temperature, environment, etc. The rate of the diffusion can increase as diffusion distance increases, concentration gradient increases, surface area increases, temperature increases, and many more.
2. Why do you think the urea was not able to diffuse through the 20 MWCO membrane? How well did the results compare with your prediction?
a. I think the urea was not able to diffuse through the 20 MWCO membrane because the urea was too big to pass through.
3. Describe the results of the attempts to diffuse glucose and albumin through the 200 MWCO membrane. How well did the results compare with your prediction.
a. Between the attempts to diffuse glucose and albumin through the 200 MWCO membrane, the results for both were that glucose was diffuse but the albumin did not. Comparing to my prediction, the results were a bit different. I predicted that both were able to diffuse, but at the end, only glucose diffused.
4. Put the following in order from smallest to largest molecular weight: glucose, sodium chloride, albumin, and urea.
a. Sodium chloride, urea, glucose, albumin

Activity 2
5. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it differs.
a. Simple diffusion moves molecules from an area of higher concentration to an area of lower concentration without an input of energy. Facilitated diffusion follows the same rules as regular diffusion (higher to lower concentration and no energy input), but uses protein carrier molecules to allow substances that are fat soluble to diffuse through the cell membrane. Simple diffusion allows non-polar molecules to pass through and a little amount of H20. On the other hand, Facilitated diffusion allows ions and polar molecules across the membrane because it contains carrier proteins. It is highly specific to substances it diffuses across the membrane.
6. The larger value obtained when more glucose carriers were present corresponds to an increase in the rate of glucose transport. Explain why the rate increased. How well did the results compare with your prediction?
a. the rate increased because there is more room and surface area increases relative to glucose.
7. Explain your prediction for the effect Na+ Cl- might have on glucose transport. In other words, explain why you picked the choice that you did. How well did the results compare with your prediction?
a. Increasing the NaCl will increase the osmotic pressure. because water needs to diffuse to the higher concentration gradient until equilibrium is reached. I predicted that it will not have an effect on the glucose transport.

Activity 3
8. Explain the effect that increasing the Na+ Cl- concentration had on osmotic pressure and why it has this effect. How well did the result compare with your prediction?
a. Increasing sodium chloride concentration, it did not have an effect toward the osmotic pressure. The reason that it did not have an effect is because the sodium chloride molecules were too small to pass through the membrane. My prediction was that it would increase the osmotic pressure, so my prediction was wrong.
9. Describe one way in which osmosis is similar to simple diffusion and one way in which it is different.
a. Osmosis is where the water or other particles go from an area of higher concentration to an area of lower concentration. This is often against a pressure gradient. This type of reaction involves active transport where ATP is required. diffusion is where the products even themselves out through a given solution. This process is done by passive transport, where no energy or ATP are required. Osmosis is diffusion through a semi-permeable membrane.
10. Solutes are sometimes measured in milliosmoles. Explain the statement, “water chases milliosmoles”
a. solute increases, water decreases
11. The conditions were 9 mM albumin in the left beaker and 10 mM glucose in the right beaker with the 200 MWCO membrane in place. Explain the results. How well did the results compare with your prediction?
a. Glucose diffuses from right beaker to the left beaker until equilibrium is reached. Albumin can't diffuse through the membrane and osmotic pressure of 153mmHg results.
Activity 5
12. Describe the significant of using 9 mM sodium chloride inside the cell and 6mM potassium chloride outside the cell, instead of other concentration ratios.
a. Potassium chloride will need the help and use active transport to enter into the cell while sodium chloride will stay inside the cell.
13. Explain why there was no sodium transport even though ATP was present. How well did the results compare with your prediction?
a. Even though ATP was present, there was no sodium transport because the transporters did not require ATP, they are not active transporters. My prediction was correct.
14. Explain why the addition of glucose carriers had no effect on sodium or potassium transport. How well did the results compare with your prediction
a. The addition of glucose carriers had no effect on sodium or potassium transport because they are not lipid soluble and glucose was too large to pass through the membrane pores. Glucose concentration does not affect the sodium and potassium concentration and it only has affect on glucose itself. My prediction was correct
15. Do you think glucose is being actively transported by facilitated diffusion in this experiment? Explain your answer.
a. I believe that glucose was being actively transported by facilitated diffusion throughout this experiment because no transport through the cell can be done without ATP. So that’s why glucose was being actively transported.