BIO/340 Multiple Cell Behavior Worksheet: Complete Solution

This assignment solution addresses a BIO/340 worksheet on multiple cell behavior, focusing on an E. coli cell with green fluorescent protein (GFP). The solution begins by observing a single cell and its fluorescence changes over time, then compares it to multiple cells. The student explores how different variables (concentration of positive transcription factor, mRNA destroyer, affinities for transcription factor and polymerase, and protein degradation) impact GFP production and expression. The solution concludes by relating the observations to bacterial and viral readings, highlighting the use of GFP in studying gene expression, protein localization, and antibiotic resistance. The student used the PHET Interactive Simulations website from the University of Colorado Boulder to complete the assignment.

BIO/340
Multiple Cell Behavior
Complete the worksheet.
Name:
1. Visit the PHET Interactive Simulations website from the University of Colorado Boulder.
2. Click “Multiple Cells.”
3. Click on “Show Real Cells” to read about the cells that you are examining in the simulation. On
the start screen of the simulation, you are shown a single E. coli cell that has green fluorescent
protein (GFP) added to its genome so that it causes the cell to glow green when presented with
ultraviolet light.
4. Observe the single cell for at least 30 seconds.
What do you notice about the color of the cell
and how it changes?
The cell fluoresces to a faint green color
when the average protein level increases
beyond the second unit of the x axis
occurring at time 14, 16 , 18 , and 22 to
24 seconds
5. Drag the slider on the bottom of the screen from “One” to “Many.”
What do you notice about the color of the cell
sand how they change?
All the cells fluoresce at different intervals
while the average protein level remains
constant throughout the 30 seconds
What do you think might cause the cells to
appear different?
While the cells have the same genetic
code, they differ in their bacterial
physiology. Some cells are faster at
expressing a protein linked to GFP than
others while some may have mutations
that denature the expression of proteins
linked to GFP.
6. Open the three menus on the right (Concentration, Affinities, Degradation by clicking the “+”
signs.
7. By maximizing the production of GFP, we can cause the cells to glow greener. See what
variables might impact the production of GFP. How can you change the following variables to
maximize the production and expression of GFP?
Concentration of Positive Transcription Factor Increasing the concentration of positive
transcription factor maximizes the
production and expression of GFP
Concentration of mRNA Destroyer Decrease the concentration of mRNA
Destroyer maximizes the production and
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Multiple Cell Behavior
BIO/340
Page 2 of 2
expression of GFP
Affinity for Positive Transcription Factor Increase the affinity for positive
Transcription Factor maximizes the
production and expression of GFP
Affinity for Polymerase Increase the affinity for Polymerase
maximizes the production and expression
of GFP
Protein Degradation Slow down the protein degradation
maximizes the production and expression
of GFP
8. Consider your readings from this week about bacteria and viruses.
How do your observations relate to the
readings from this week?
The observations on green fluorescent
protein indicate that the physiology/
protein expression of a micro-organism
can be tracked by using a tracer/ tagging
a protein. This observation is further
supported by the changes in gfp
expression that occur when the protein
expression mechanisms are altered.
From the readings of this week on
bacteria. GFP can be used to study gene
expression, protein localization and
interactions. Additionally, the readings on
antiobiotic resistant strains have been
shown to express proteins such as beta-
lactamase that confer resistance to
penicillins. It can be theorized that GFP
tagging can be used to identify such
proteins in antimicrobial susceptibility
test.
Copyright 2019 by University of Phoenix. All rights reserved.