Transcript Cell Signaling (PowerPoint) Southeast 2013

Cell Signaling
Greg, Lauren, Nancy, Mark, Gene
Facilitator: Paula
Cell Signaling
Level
Introductory biology
Knowledge of students prior to unit
Cell theory
Characteristics of life
Homeostasis
Chemistry of macromolecules
Cell Signaling
Learning Goals:
• Understand why cells need to communicate.
• Understand the cellular processes involved in
cell communication.
• Examine the effects of cell signaling
malfunctions.
 Learning Outcomes:
•
•
•
•
•
Describe the sequence of events that takes place in cell
signaling.
Discuss the relationship between the chemical nature of
ligands and the location of their cellular receptors.
Design and/or evaluate experiments to elucidate the
chemical nature of a ligand and the signaling pathway it
induces.
Explain why different types of cells may respond
differently to the same chemical signal.
Write a synopsis of a cell signaling pathway gone awry.
 Learning Outcomes:
•
•
•
•
•
Describe the sequence of events that takes place in cell
signaling.
Discuss the relationship between the chemical nature of
ligands and the location of their cellular receptors.
Design and/or evaluate experiments to elucidate the
chemical nature of a ligand and the signaling pathway it
induces.
Explain why different types of cells may respond
differently to the same chemical signal.
Write a synopsis of a cell signaling pathway gone awry
How Would You Improve the USPS?
General Themes
Let’s complete this table
Signal Molecule
(ligand)
Receptor Location
Response
Prior
Knowledge
S-Steroid Hormone
P-Protein Hormone
M-Membrane
I- Intracellular
E-alters enzymes
activity first
G-alters gene
expression directly
Write down
anything you
may know
about the
ligand.
Testosterone
S
I
G
Glucagon
P
M
E
Progesterone
Insulin
Growth Hormone
Nature of Signal
Molecule
Let’s complete this table
Signal Molecule
(ligand)
Nature of Signal
Molecule
Receptor Location
Response
Prior
Knowledge
S-Steroid Hormone
P-Protein Hormone
M-Membrane
I- Intracellular
E-alters enzymes
activity first
G-alters gene
expression directly
Write down
anything you
may know
about the
ligand.
Testosterone
S
I
G
Glucagon
P
M
E
Progesterone
S
I
G
Insulin
P
M
E
Growth Hormone
P
M
E
Clicker Question
Arrange the steps of cell signaling in the correct
order:
a)
b)
c)
d)
e)
Reception
Response
Response
Transduction
Transduction Response
Reception Transduction
Transduction Reception
Transduction
Reception
Reception
Response
Response
Let’s dig a little deeper
Close your book and all notes.
2. Take about 2 minutes and draw a diagram of the
generalized cell signaling pathway for a:
1.
1.
2.
Protein Hormone
Steroid Hormone
Compare your diagrams with a partner. Make sure
that together you have a complete story.
4. You may use your texts to verify your diagrams.
3.
Watch this animation at home to review: http://youtu.be/FkkK5lTmBYQ
Clicker Question
BPA binds to an intracellular receptor. BPA is
likely to be a:
a)
b)
c)
d)
e)
Protein/Peptide
Carbohydrate
Steroid/Lipid
Nucleic acid
Not enough information
Clicker Question
BL19 cells respond to both ligands X and Y as described in the table
below:
Ligand
Chemistry
Response in BL19
Cells
X
Steroid hormone
Cells turn green
Y
Protein hormone
Cells turn red
If both X and Y are added to a culture of BL19 cells, the cells
become yellow (a mixture of red and green). A protease that cannot
enter the cells is added to a culture of BL19 cells and then washed
off. If X and Y are both added to the protease treated cells, the cells
would turn:
a) Red
b) Green
c) Yellow
d) Blue
Write, Pair, Share
Now, take a minute to write out a justification for
your response.
2. Pair and Share your justifications.
1.
Clicker Question
BL19 cells respond to both ligands X and Y as described in the table
below:
Ligand
Chemistry
Response in BL19
Cells
X
Steroid hormone
Cells turn green
Y
Protein hormone
Cells turn red
If both X and Y are added to a culture of BL19 cells, the cells
become yellow (a mixture of red and green). A protease that cannot
enter the cells is added to a culture of BL19 cells and then washed
off. If X and Y are both added to the protease treated cells, the cells
would turn:
a) Red
b) Green
c) Yellow
d) Blue
Group Assignment
Thyroxin is a major hormone produced in the thyroid gland, affects virtually every cell
in the body. An experiment to investigate the mechanism of thyroid hormone signaling
was conducted in rats. Scientists first surgically removed the thyroid gland from the
rats in the experimental group (THX). The rate of protein synthesis was then measured
in experimental (THX) and control rats by measuring the rate of radioactive leucine
(3H-leucine) uptake by liver cells. The rates of protein synthesis for both groups of rat
are shown in the table below.
Group
Rate of protein synthesis
THX rats
150
Control rats
225
1. From this experiment, I would predict that thyroxin binds to a(n) ________ receptor.
a)
cell surface receptor
b)
intracellular receptor
2. The reason for my answer is: