Anatomy and Phys I

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 2: Simulated Facilitated Diffusion Lab Report
Pre-lab Quiz Results
You scored 75% by answering 3 out of 4 questions correctly.
1. Molecules need a carrier protein to help them move across a membrane because Your answer : c. they are too large.
Correct answer: d. they are lipid insoluble or they are too large.
2. Which of the following is true of facilitated diffusion?
You correctly answered: c. Movement is passive and down a concentration gradient.
3. Examples of solutes that might require facilitated diffusion include You correctly answered: d. all of the above.
4. Which of the following would not affect the rate of facilitated diffusion? You correctly answered: a. the amount of intracellular ATP
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Experiment Results
Predict Question:
Predict Question 1: What effect do you think increasing the number of protein carriers will have on the glucose transport rate?
Your answer : a. The glucose transport rate will decrease.
Predict Question 2: What effect do you think adding Na+ Cl- will have on the glucose transport rate? Your answer : a. The glucose transport rate will increase.
Stop & Think Questions:
What happened to the glucose transport rate when the glucose concentration was increased from 2 mM to 8 mM?
Your answer : b. The glucose transport rate decreased.
Correct answer: a. The glucose transport rate increased.
Describe the conditions that resulted in the fastest rate of glucose transport. Your answer : a. 500 glucose carrier proteins and 2 mM glucose
Correct answer: d. 700 glucose carrier proteins and 8 mM glucose
Why do you think equilibrium wasn't reached?
You correctly answered: b. The membrane proteins were saturated.
Experiment Data:
Run Number
Solute
Start Conc. L
Start Conc. R
Carriers
Rate
1
Glucose
2.00
0.00
500
0.0008
2
Glucose
8.00
0.00
500
0.0023
3
Glucose
2.00
0.00
700
0.0010
4
Glucose
8.00
0.00
700
0.0031
5
Glucose
10.00
0.00
100
0.0017#
6
Na+ Cl-
0.00
2.00
700
0.0042
6
Glucose
2.00
0.00
700
0.0010
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page 2
Post-lab Quiz Results
You scored 50% by answering 2 out of 4 questions correctly.
1. What variable(s) increased the rate of facilitated diffusion of glucose? You correctly answered: d. both a and b
2. For facilitated diffusion, increasing the concentration of glucose on one side of the membrane is the same as Your answer: c. adding ATP
Correct answer: b. making the concentration gradient steeper
3. When all of the membrane carriers are engaged, or busy, we say they are You correctly answered: a. saturated.
4. Na+ Cl- had no effect on glucose transport because
Your answer: d. the membrane proteins were saturated.
Correct answer: b. sodium is not required for glucose transport in the simulation.
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Review Sheet Results
1. Explain one way in which facilitated diffusion is the same as simple diffusion and one way in which it is different from simple diffusion.
Your answer:
They are both passive processes and the solute can only diffuse down its concentration gradient. Facilitated diffusion requires the presence of a membrane-bound carrier protein in order to occur, while simple diffusion does not.
2. 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?
Your answer:
The results compared differently from my prediction. As I had predicted they rate would decrease and it did not. The more carriers available allowed for a more expedited transport rate.
3. 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?
Your answer:
My prediction proved to be correct. The effect of NaCl increased the rate of transport as compared to the othe solutes. I believed that by adding NaCl would facilitate the transport rate significantly.
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