physioEx 9.0 Exercise 1 Act 2

Name: Ashlei Sickles 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 You correctly answered: d. they are lipid insoluble or they are too large. 2. Which of the following is true of facilitated diffusion? Your answer : d. Movement is active and down a concentration gradient. Correct answer: 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 : b. The glucose transport rate will increase. Predict Question 2: What effect do you think adding Na+ Cl- will have on the glucose transport rate? Your answer : c. There will be no change in the glucose transport rate. Stop & Think Questions: What happened to the glucose transport rate when the glucose concentration was increased from 2 mM to 8 mM? You correctly answered: a. The glucose transport rate increased. Describe the conditions that resulted in the fastest rate of glucose transport. You correctly answered: 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 1 1 2 2 3 3 4 4 6 6 8 8

Solute Na+ ClGlucose Na+ ClGlucose Na+ ClGlucose Na+ ClGlucose Na+ ClGlucose Na+ ClGlucose

Start Conc. L 0.00 2.00 0.00 8.00 0.00 2.00 0.00 8.00 2.00 2.00 0.00 10.00

Start Conc. R 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00

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Carriers 500 500 500 500 700 700 700 700 700 700 100 100

Rate 0.0000 0.0008 0.0000 0.0023 0.0000 0.0010 0.0000 0.0031 0.0042 0.0010 0.0000 0.0028#

Post-lab Quiz Results You scored 100% by answering 4 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 You correctly answered: 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 You correctly answered: 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: Both are passive diffusion that are from a high to low concentration gradient. Faclitated diffusion requires a carrier protien to diffuse where 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 rate of glucose transportation increased when more glucose carriers were present, since more glucose molecules could bind to the glucose carriers present. This resulted in an increase number of glucose molecules to cross the membrane. My prediction was supported by the results. 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: Na+ Cl- will not affect the rate of glucose transport, because Na+ Cl- is transported by simple diffusion. Therefore, Na+ Cl- is completely independent from the glucose transport. My prediction was supported.

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