Cell Signaling Greg, Lauren, Nancy, Mark, Gene Facilitator: Paula
Dec 18, 2015
Cell SignalingGreg, Lauren, Nancy, Mark, Gene
Facilitator: Paula
LevelIntroductory biology
Knowledge of students prior to unitCell 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.
Cell Signaling
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)
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
Insulin
Growth Hormone
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) Reception Response Transduction
b) Response Transduction Reception
c) Transduction Response Reception
d) Reception Transduction Response
e) Transduction Reception Response
Let’s dig a little deeper
1. Close your book and all notes.
2. Take about 2 minutes and draw a diagram of the generalized cell signaling pathway for a:
1. Protein Hormone
2. Steroid Hormone
3. 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.
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) Protein/Peptide
b) Carbohydrate
c) Steroid/Lipid
d) Nucleic acid
e) Not enough information
Clicker QuestionBL19 cells respond to both ligands X and Y as described in the table below:
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
Ligand Chemistry Response in BL19 Cells
X Steroid hormone Cells turn green
Y Protein hormone Cells turn red
Write, Pair, Share
1. Now, take a minute to write out a justification for your response.
2. Pair and Share your justifications.
Clicker QuestionBL19 cells respond to both ligands X and Y as described in the table below:
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
Ligand Chemistry Response in BL19 Cells
X Steroid hormone Cells turn green
Y Protein hormone Cells turn red
Group AssignmentThyroxin 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.
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:
Group Rate of protein synthesis
THX rats 150
Control rats 225