[PhysioEX Chapter 1 exercise 2] PEX-01-02

Solved by ramonistry

Exercise 1: Cell Transport Mechanisms and Permeability: Activity 2: Simulated Facilitated Diffusion Lab Report
Pre-lab Quiz Results
You scored 100% by answering 4 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?
   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

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 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

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.

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 of diffusion are passive diffusion that are from high concentration to a low concentration. Facilitated diffusion differs
   from simple diffusion because facilitated diffusion requires a carrier protein to diffuse.
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:
   There is more way for glucose. So rate of diffusion was increased, as predicted.
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:
   The rate of glucose diffusion did not change because sodium chloride does not use protein carrier so it does not help or
   hinder glucose diffusion.