Why are my cells different?
St. John Fisher College:
Noveera Ahmed
Ed Freeman
Worcester Polytechnic
Institute:
Joe Duffy
Ally Hunter
Luis Vidali
Facilitators:
Jennifer Nauen, University of Delaware
Jessamina Blum, Yale University
Classroom Setting
Freshman Level Course: Introductory Biology
Coverage to this point includes:
scientific method,
cell theory,
structure/function/replication of DNA,
transcription and translation
Our UNIT – Eukaryotic Gene Expression
(The Next Theme: Gene Regulation)
Learning Goals
Learning Outcomes
1. Students will have conceptual
understanding of the central dogma.
2. Students will have conceptual
understanding of What a gene is?
3. Students will understand the role of the
central dogma in cellular differentiation
4. Students will appreciate our limits in
understanding gene expression (past and
future).
3. Students will be able to:
a. create a concept map to review the flow of
genetic information in a cell.
b. identify and explain the various levels at
which gene expression may occur.
c. interpret and construct graphical
representations of data.
d. apply this understanding to a novel
situation
e. appreciate the biological significance of
diversity.
Eukaryotic Gene Expression
Lesson objectives:
• be able to create a concept map to review the flow of genetic information
in a cell.
• be able to identify and explain the various levels at which gene
expression may occur.
• be able to interpret and construct graphical representations of data.
• be able to apply this understanding to a new situation
• be able to appreciate diversity within and between organisms.
Why are my cells different?
What are the differences?
Let's review Central Dogma – build a concept map.
1. In your small groups, write the
following terms on the provided post-it
notes
DNA
RNA
Protein
Transcription
Translation
DNA
2. Use markers to draw the
location of the nucleus and
cytoplasm with respect to your
labeled sticky notes
Central
Dogma
DNA
Nucleus
Transcription
RNA
Cytoplasm
Translation
Protein ?
What
happens if
Transcription
is off?
Central
Dogma
DNA
Nucleus
Transcription
RNA
Cytoplasm
Translation
Protein ?
What
happens if
Translation is
off?
Let's consider this in the context of differences in cell types
• What do the data in the graph below demonstrate? Consult with your
neighbor and write a one sentence description.
Myosin
protein
levels
Cardiac
Muscle
cell
Epidermal
Skin cell
Myosin is a family of proteins that play a role in a
variety of cell processes including muscle contraction.
Clicker question:
Myosin levels are different.
How can this be explained?
A.Regulation of Transcription.
DNA
Nucleus
Transcription
B. Regulation of Translation.
RNA
Cytoplasm
Translation
Protein
Using your Clickers answer the following question:
Where is the greater similarity in DNA?
A. between different cell types in the same individual.
B. between same cell types in different individuals.
What about differences between cells?
Keratin is a key structural
protein making up the
outer layer of skin.
Let's revisit diversity...
On the graphs you were given:
Plot your understanding of gene
expression plot with a neighbor the
expected protein levels of Keratin.
Duff’s cells
Keratin
protein
levels
Epidermal
Skin cell
Cardiac
cell
Neuron
White blood
cell
Duff’s cells
Keratin
levels
Skin cell –
keratinocyte
Cardiac
cell
Neuron
White blood
cell
We predict:
Different levels of Keratin are expressed in different cell types!
Given your understanding of gene
expression plot with a neighbor the
expected protein levels of Keratin.
Keratin
Protein levels
in epidermal
cell
Noveera
Ed
Ally
Luis
Duff
Skin cell - keratinocyte
Keratin
levels
Noveera
ED
Ally
Luis
Duff
Different people have similar levels of
Keratin expression in Skin cells (keratinocytes)!
Through changes in gene expression diversity
in cell types can arise!