BIO308: Cell Biology            Dr. Karen Bernd
Classes: TR 8:30-9:45 Chambers 1006
Labs: Wednesday 1:30-4:20 or Thursday 1-4 Dana 220
kabernd@davidson.edu
Watson 289:  894-2889

In order to understand how something works it is sometimes easiest to break it into its smallest parts, figure out how they work and build up from there. It is known that the 'smallest part' of an organism is the cell. Research has shown that from organisms having only one cell (bacteria and yeast) to those with many multicellular organs (plants, insects and animals) complex sets of interactions between cellular components control how cells live and die. We will cover the basic parts of the cell in the context of these interactions by comparing normal and 'diseased' systems as case studies. The textbook and accompanying computer animations will be used as reference material and scientific journal articles on related topics will be used to bring the concepts into a broader context. The goal is to understand the concepts committed to textbooks, to be able to critically analyze current dogma and to suggest what the next questions might be and what approaches can be used to investigate them.

Required materials

Molecular Biology of the Cell (4th edition) by Alberts et al.Available in the bookstore
Cell Biology Interactive CD-ROM--
Packaged with the text. If buying a used textbook, be sure it has the CD-rom
Bio308 Laboratory Manual
-- Provided as links from homepage. Download and print.

Our study will follow the the example of cellular organization. Cellular processes are equisitely intertwined and balanced, therefore our case studies will draw on multiple chapters, animations and web readings. A Course Guide containing discussion questions is included as part of the syllabus. Use these to help you focus your reading and class preparation.

Class periods I expect class participation so you must come to class and be prepared. It is an 8:30 class so do what you must to get here awake and alert. We will be using a case study approach where a particular disorder provides the framework for a discussion of topics in Cell Biology. WORDS OF WIDSOM FROM PREVIOUS STUDENTS:
During the class period laboratory concepts will be introduced. The labs are designed to let you 'do science'. They give you hands-on experience with commonly used tools of cell biology and allow you to apply the principles covered in the lecture period. This overlap should underscore the fact that the lab and lecture portions are integrated to allow fuller understanding and reinforcement of concepts

Laboratory sessions will be divided into two units. In the first techniques used to characterize the yeast mating reaction will be introduced and you will design experiments to investigate extracellular and intracelular signaling. In the second unit you will characterize yeast strains that are defective in the mating process. Because research requires planning and technical training as well as the ability to interpret data and communicate those results, each unit concludes with an individually written assignment. Throughout the semester there will be online assignments in Blackboard. Surveys are not graded but pre-post lab assignments are. The Blackboard assignment scores are part of your lab grade.

Attendance policy and Participation: Your participation in class is noted and graded (see grading below). Voluntary participation is looked on very favorably but keep on top of the material since questions will also be asked. It is in your best interest to be present since attendance is expected. An 'A' for participation requires preparation and participation in class that is consistent and of very high quality. (If you did not complete a written assignment you would expect to get a '0' on it. Not coming to class, coming to class unprepared or never speaking is equivalent to forgetting to complete this assignment and will be evaluated as such.)

Lab meets from 1-4 or 1:30-4:20 on the designated day. It should go without saying that you will not miss lab or make other appointments that coincide with your entire1-4pm or 1:30 - 4:20pm laboratory period. Failure to follow this rule will cause a penalty of -4pt from your final course grade.

We will work with live organisms that require certain amount of growth time between steps. This means that some lab set up or observations must be made outside of scheduled lab sections. During those times each group must coordinate how and when you will meet. Regardless of who is performs a certain task, every person is responsible for completing the procedures and for making sure that you have the data. The Cell Bio site on Blackboard includes group 'file exchanges' that lab groups can use to store and distribute material.

Questions regarding the material covered in a written assignment, how to prepare for class, or how to study can be made at any time. Ask early and often! Talk to me during or after class and lab, by email or in my office. I am happy to review first drafts of papers if they are given to ahead of time (at least 2 days before due date). I provide alot of feedback on exams and papers. Read the comments so that you learn how to improve the next time. Progress is the expectation.
Questions regarding the evaluation of a written assignment (paper or review) must be made within 10days of your receiving the graded material. Contact me to make an appointment at a time that is convenient for both of us.

Grades
Grade Scale
2 exams during the semester 48% 
1 final exam  25%

Materials and Methods (2%),
CV (2%),
Lab Article (7%)
Lab presentation (4%)

15% 
Opinion Paper 4%
Lab Participation, Blackboard assignments  5%
Class participation  3%
A 100-93 B+ 89-87 C+ 79-77 D+ 69-67 F < 59
A- 92-90  B 86-83  C 76-73 D 66-60  
  B- 82-80 C- 72-70    

Papers/Reviews/Exams and the Honor Code

Note that the due dates/times are often outside of scheduled class meetings. All assignment dates are scheduled now and will not change make sure you put them in your schedule now. In lab we will discuss that grant and job applications in science are submitted by a certain deadline. Miss the deadline, by even a minute, and you have no shot at that funding or job. Plan to turn in an assignment with time to spare as late assignments are not an 'option' to be chosen and are penalized (subtract 5% for 1min late and an additional 5% for every 60min after that)
I must be notified as soon as possible for the rare possibility of other arrangements (not the day or the hour it is due). You have the schedule and have more than one day to complete the assignments. Last minute computer/printer problems, 'walking up the hill', other exams, papers, social functions, performances or sporting events are not acceptable reasons for exceptions to this rule. Since hall clocks vary in different buildings my computer clock (standard across campus) or cell phone represents the official time.

All of your reviews/exams
are "take-home" exams. They are designed to be completed in 2 hours (3 hours for final) but you will have more than 2 days. Exams are distributed by email on or before the day indicated on the syllabus. The exams are to be completed by you alone, without text, notes, or other written/verbal/telepathic communication pertaining to the questions. Any use of such material is a violation of the honor code and must be reported to me or the Dean of Students. Any knowledge of a classmate using such materials must also be reported. Exceptions to this rule are not allowed.

Written assignments are due as indicated in the syllabus. For Lab projects lab groups will, obviously, compile data together. You may discuss possible interpretations and share reference materials but all writing must be your own. Do not read each others drafts or discuss how you would describe or word particular sections of your paper. Be sure to include proper in-text references and end of paper bibliographies for all sources used-- this includes lab manuals and online resources as well as texts and journal articles. Bibliographic references to texts and articles must follow the style and format used in the journal Cell. (see http://www.cell.com/misc/authors.shtml). References to online resources must follow the MLA format for online sources (see http://www.bedfordstmartins.com/online/cite5.html#1 ). There is no such thing as the 'three source rule' and not providing proper credit is plagiarizing. Read the DEPARTMENTAL STATEMENT ON PLAGIARISM. If you have questions--- ASK BEFORE YOU TURN SOMETHING IN.

Accommodations for Students With Disabilities: I am happy to provide accommodations for students with learning or physical disabilities.  If you are a student with a learning disability documented by Davidson College please identify yourself to me within the first two weeks of class so that arrangements can be made.  Students with other disabilities are encouraged to self-identify so that we may discuss if there is any way in which I can make accommodations that will enhance your learning experience.  All such discussions will be fully confidential unless you otherwise stipulate.



BIO308 Cell Biology: Laboratory Syllabus
Dana 220    Tues 1-4 or Wed 1:30-4:30
Week
8/27 Lab overview LAB MEETS FIRST WEEK
Blackboard Survey DUE BY FRIDAY 8/31 5pm
Lab Safety/ Microscopy/ SterileTechnique/Brainstorming
9/3

Quiz 1 due Tuesday Sept 4th 11:59pm   (covering safety/microscopy/sterile technique AND reading for week of this week)
Unit 1: Learning techniques and Determining our baseline of response (Defining 'normal')
Unit 1:
'The Signal 'and How Yeast Respond to It :
Techniques for characterizing yeast mating reaction 

9/10 Quiz 2 due Tues Sept 11th by 11:59pm (covering results from last week and reading for this week)
Unit 1:
'The Effect'  Part I -changes over time

What happens during long term exposure?
9/16 Quiz 3 due Tuesday Sept 18th by 11:59pm (covering results from last week and reading for this week)
Unit 1:
'The Effect'  II-
How much mating is 'normal'?
9/24

Quiz 4 due Tuesday Sept 25th by 11:59pm
Unit 1:
'The Effect' Part III Differential gene expression Detecting and quantitating gene expression patterns .
Work on Materials and Methods.
DUE Friday 9/28 before noon: Material and Methods

10/1

Mini unit: How do scientists communicate? Grants and Funding

10/8

Unit 2: New and special for Fall 2007
Wed lab: Should you run outside? Study of the combined affect of increased metabolism and ozone on the redox state of lung alveolar cells
Thurs lab: Do longer 'arms' make a stronger swimmer? Using a laser trap to examine the relationship between length and swimming force in Chlamydomonas long flagella (lf) mutants.

See instructions for final project and final article in lab manual links.

Background reading for your project will be discussed in lab

10/15 DUE: Funding Opinion Paper due Beginning of your lab period. We will discuss the opinion papers at beginning of lab

Overview of curriculum vitae assignment

Prepare for next weeks' experiments
10/22

DUE in lab: Curriculum vitae

Wed: Make ozone and expose L2 cells that were grown +/- increased metabolism, Learn metabolic rate assay and imaging. Sample for metabolic rate assay. FRIDAY pm: make lysate
for GSH assay

Thursday: Learn laser trapping method and image analysis of flagellar length. Establish stds for full length wt and lf mutants.

10/29 Wed: Perform glucose metabolism and GSH level assays.
Thurs: Deflagellate cells and measure length and force during 2hr flagella regeneration period.
11/5 Analyze data: including graphs, representative pictures, statistical analysis. Begin literature search
11/12 Bring relevant articles. W.O.P.
11/19 (Thanksgiving Break)
11/26 Your initial sections of lab article posted to Blackboard by 8:30am Tuesday Nov 27th.
Revisions are due in your laboratory period.
12/3

Lab cleanup
Discussion of Paper 3: Austriaco, Jr and Guarente 1997 PNAS vol94 9768-72

Course evaluations
Present your findings in class on Thursday (10min ppt)

Lab Article Portfolios due Friday before 5pm,

12/10 Optional Class days-- no scheduled lab


BIO308 Cell Biology: Class Syllabus
Chambers 1006 TR 8:30-9:45am

Required Text: Alberts et al. Molecular Biology of the Cell, 4th Edition
CD-ROM-- one of the following is supplied with the text. 'reading' can be done from either.
CBI
refers to Cell Biology Interactive-- the CD-ROM Packaged with Alberts
To use CBI: Some computers have problems running this CD-rom's platform. If installing and clicking on the CBI icon doesn't work use the following work-arounds.
To view movies and animations: open the disc, open the assets folder and select files directly (the numbers in the syllabus are the 'names').
To view the molecular models you must have CHIME and Netscape on your computer. Installing CBI should install these subprogram and both are part of computer lab standard setups. Open Netscape Communicator. Under the Communicator File menu choose open/ page in navigator. Use the dialog box to open the CBI folder and the cbis folder within that. Choose any of the .htm files listed. This will bring up an interactive interface with chapters on the right. From this interface you can open the files listed below according to their numbers. Note: this interface is unstable and may randomly quit. If it does, force-quit and restart.

ECB= Essential Cell Biology 2 (newer version of CD-rom included in some texts). This one gets around all the interface problems with CBI.

See syllabus for Biology Related Seminars (in green). I encourage you to attend them all. There are options on different afternoons and evenings.
You can earn extra credit for attending three (3). To receive the credit you must:
a) attend the entire seminar b) email me a brief overview of the seminar within 72hours.
Each summary will add 1pt to the review most closely following the event (up to 3 pt over the semester).
Ask a question: If you ask the seminar speaker a question you can receive an additional 1pt. Provide the question and the response as part of your summary.

Week   Topic/Text Reading
8/27 T

Introduction to course, Overview of case studies
READING (yes, for today)
## Class Syllabus
##Departmental Statement on Plagiarism
##The Practice of Science At the Edge of Knowledge 
By Frederick Grinnell  http://www.faseb.org/opar/newsletter/6x00/guest.htm
What is the role of methodology in science? of intuition? of luck? of good PR?

  R

Background: Why Cell biology is more than histology: Biological Membranes and Cellular components

Review Ch 10

CBI 10.2 Lipids and Lipid Bilayer or
ECB 11.1, 11.2, 11.3

The Virtual Cell
CBI 2.6 Lipids CBI 1.1 Keratocyte Dance or
ECB 1.1
Ch12 (659-666)

Two classes reviewing background-- Need know the players before anything else.
In chapter 10 focus on the roles and components of biological membranes (pg583-602)
CBI animations and videos-- Use these to see the components of a membrane. The keratocyte is an example of membrane fluidity. Notice how it can re arrange the components to generate force and move.
The Virtual Cell (http://personal.tmlp.com/Jimr57/textbook/chapter3/chapter3.htm)
Make sure you are familiar with all of the cellular components and their functions. Explore the site. Note when you click on an organelle the popup window has navigation buttons at the top--use them to zoom in and out.
In Chapter 12 focus on how organelles are 'connected' (p659-666)

What role do biological membranes play in the cell? What are the components that make them up? How are they important to its function? What are the fluid mosiac model and lipid rafts? How do biological membranes define organelles and what the organelles? (Is everything in the cell an organelle? what kinds of cells have organelles and what kinds do not?)

9/4 T

Cellular components part II: No Cell is an island
Introduction to Case Study I: Grave's Disease-- Symptoms. Causes?

What are the functions of organelles and other cellular structures? Think about the interplay or connections there between a cell and its environment? Compare and contrast this interaction for a multicellular organism vs a single celled one.

  R

Communication is the key.
With Graves' disease and many other disorders the symptoms can be summed up by quoting the movie classic "Cool Hand Luke"-- 'What we have here is a failure to communicate'. The problem is that there are many ways to mess up communication-- what has appened in Graves' disease to cause excess secretion of T3 and T4? In the next four classes we will discuss 'normal' extracellular signalling, how the mechanisms cells use to perceive those signals and what happens once the signals get in. During this section keep two questions in mind-- 1) How could these molecular mechanisms be altered to result in the symptoms seen in Graves' disease and 2) How does this relate to the mating interactions we are examining in lab?

I. Extracellular signaling and the receptors that mediate it.

832-836 stop at 'Each Cell..., 852-854 stop at 'Cyclic-AMP...' 886-892 'Some protein...' to end of 892
Fig15-4 871-876 stop at 'Ras is...' http://www.bio.davidson.edu/people/
kabernd/cb/restricted/figures/Thyroidsignal.gif
839-843 stop at 'Most Activated...' 882-884 'Tyrosine-kinase...' to 'Cytokine...'  

What are the types of extracellular signaling? Which types might be faster/slower (why)? Given the diagram of normal thyroid signaling what types of extracellular signaling are being used? What are the types of cell surface receptors? (Some signaling molecules don't use cell surface receptors-- how do they get in?) Given the symptoms of Graves' disease what might be going wrong in the thyroid signaling pathway? (Think of more than one possibility and how you might test it)
In class we will discuss the exact types of receptors involved in pathway connected to T3 and T4 release.

Thursday Sept 6th 7pm Chambers Gallery
Celebration of Davidson Summer Research-- Poster Session in Chambers Gallery. (for extra credit must speak with three poster presenters and provide one or two sentence summary of their research)

Friday, Sept 7th, 2PM
Dr. Larry Mimms ('76), Exec VP of R&D, Gen-probe
"Blood wars: The role of viral nucleic acid testing in blood safety"

9/11 T

II. So many signals--how does a cell know when to react? Specificity and the receptor

129-143 stop at 'Proteins can fold..' CBI 3.5 & 7.3 (ex 3° struct)
ECB 4.5
156-163 stop at 'Enzymes speed...'
CBI 2.4 Amino acids (ex 1° struct) CBI 3.8 (ex 4° struct)
ECB 4.6
 
CBI 3.1 & 3.2 (ex 2° struct)
ECB 4.1 & 4.2
CBI 24.1 Antibodies
ECB 4.8
 

Interactions require the proper fit between receptors and ligands. Since all of the receptors we know are proteins we need to discuss proteins and protein folding before we can get to binding specificity.

What are the amino acids and how do they come together and fold up into proteins? What are the levels of protein structure? What ways can you think of to change a protein's folding? What are binding sites and active sites? How do antibodies (CBI 24.1) exemplify binding specificity? Knowing that TSH, T3 and T4 are the hormones involved and TSH receptor is found on the thyroid cells and is activated by TSH what structural changes could result in an overstimulated thyroid?

  R III. Getting the signals in--Conformational changes to allow communication.
593-599 'Membrane proteins...' stop at 'The cytosolic side...' CBI 3.9 Aspartate Transcarbamylase

CBI 5.1 DNA helicase
ECB 6.2

172-177 'Allosteric enzymes' stop at 'A Eucaryotic...' CBI 14.1 ATP synthase
ECB 14.3 (14.4)
 

The ligands (signaling molecules) we have discussed are outside the cell. The plasma membrane is a barrier that these hormones cannot cross. In this class we will discuss how the receptor-ligand interaction allows a signal to cross the membrane even though the ligand stays 'outside'.

The Chapter 10 reading reviews membrane proteins like the TSH receptor. The enzyme reading and CBI animations show the effects of interactions between molecules.

What is the relationship between a proteins's conformation (shape) and its function? TSH is polar (can't get across the thyroid cell membrane by itself) how could it have an effect on the thyroid cell? Why don't all cells react to TSH? What could be happening to cause the thyroid to be overstimulated in Graves' patients?

9/18 T

IV. Response Cascades and 2nd messengers.

842-852 stop at 'Signaling...' Fig 15-61 (883) http://www.bio.davidson.edu/courses/
immunology/FLASH/IP3.html
Summary on 870 CBI 15.4 cAMP signaling
ECB 16.3
http://www.biocreations.com/animations/MAP_Kinase.swf

What are second messengers? Why do we need them? Why do you think the cell uses these molecules as second messengers? What do they have going for them? What is a second messenger cascade? What are examples of some? The TSH receptor is a G-protein coupled receptor, what signaling cascade would you predict it is connected to? Stopping a cascade is as important as starting one, how do each of the cascades you listed stop and what makes the cell return back to resting levels of the signaling molecules? Graves' disease causes overstimulation, what could be wrong in the signaling cascade that would cause it to be overactive?
R

Activation by another means & Introduction to paper discussion (how we'll do it)

1363-4 stop at 'Lymphocytes...' The immune system and autoimmune diseases (downloads a pdf)

The pdf is a good brief introduction to the immune system and immune responses. Read sections through 'Genetic factors'. This reading may seem to be a jump- what could antibodies have to do with Graves' disease right?

Think about the connection between antibody form and function. How does the body realize that it 'should' mount an immune attack? What happens during an immune response? What happens (to the body) when the immune system loses the ability to differentiate between self and non-self? How could autoimmune diseases be related to an overactive thyroid?

Introduction to paper discussion (how we'll do it)

9/25 T

Paper 1: A. Hammes et al. 2005. Role of endocytosis in cellular uptake of sex steroids. Cell 122; 751-762.
Discussion of Terms, Techniques and Background (see handout/blackboard)

  R

Discussion of Hammes et al. (2005) paper
Review 1
available by 8:30am (due Monday 9/24 before 11am ) Reread Syllabus sections regarding Papers/Reviews/Exams and the Honor Code Policies

Thursday Sept 27th 4:30PM
Matt Talbert ('05) Molecular Medicine Program, Wake Forest Scholl of Medicine
"Unraveling the genetics of the human obesity epidemic"

10/2 T

Introduction to Case Study 2: Bipolar Disorder

The Neuron and The Nerve message http://www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookNERV.html

(stop at Nerve systems)

637-643 'Function...' to 'Patch-clamp...'

645-650 'Transmitter...' to 'Single Neurons...'
Fig 13-61 (763) Fig 11-26 (638)  

Review parts of synapse/overview of normal nerve transmission
Background on Bipolar disorder will be presented. It is a mental illness that effects neuronal transmission resulting in wide variations in mood that are very disruptive to the individual's life.What is a neuron? A synapse? What are the types of synapses and how are signals passed across them? Think about the types of problems-- at the molecular level-- that could cause not just depressed or elevated moods but wide swinging of the pendulum between these two states.


  R

 The players: Neurotransmitters and their receptors

646-656 'Chemical...' to end http://www.bio.davidson.edu/people/kabernd/cb/restricted/figures/signals_n_receptors.html
The 'Catecholamine theory of affective disorder' proposes that mania and depression are caused by changes in the amount of activity at noradrenergic receptors. To discuss this proposal we need to make sure the basics are covered first-- the types of synapses are already covered. What are the compounds that mediate signaling at the synapse? What types of receptors are involved with and what kinds of responses do they elicit?
Why might the fact that amino acids, nucleotides/nucleosides and peptides are used as neurotransmitters cause potential problems in the body? What else do these molecules do? How does the body get around these problems? What are excitatory and inhibitory synaptic responses? What are the two basic classes of neurotransmitter receptors? How are they similar and different?
What differences would you predict between the relative amount of hydrophobicity/hydrophilicity of a neurotransmitter and a neurotransmitter receptor? (why)
10/9 T

Tale of 2 proteins: neuropeptide and neurotransmitter receptor
Protein #1: Cytosolic neuropeptide--How is it made?

(DNA/Transcription/Translation--in a day--should be a review)
If a person with bipolar disorder suffers from varied activity at a synapse then perhaps there is a problem with the way the signaling molecule is made or packaged. Neuropeptides and many neurotransmitters are made from amino acids. Neuropeptides are proteins and epinephrine and norepinephrine are tyrosine derivatives (so an enzyme--a protein-- modified the tyrosine). All neuronal signaling molecules must be able to diffuse across the synaptic cleft. So how do you make a diffusible protein? How do you get it into a synaptic vesicle so that it can be released during synaptic transmission?

CBI 2.5 Nucleotides
ECB 2.3
CBI 6.1 RNA structure
ECB 7.1
CBI 2.4 Amino Acids
CBI 4.1 DNA structure
ECB 5.1
CBI 6.3 tRNA
ECB 7.4
CBI 6.4 mRNA translation
ECB 7.5 and 7.6
191-197 (all) 299-319 end of page 335-352 stop at 'There are...'
  326-329 stop at 'Many... 364 Fig 6-90

Yes today's reading is long. Yes it covers alot of material but it should be review. DNA structure, transcription and translation are some of the topics you should have had at least twice in your biological career so we will move on to how these basic principles would relate to 'our' neurotransmitter at noradrenergic receptor. The animations are the short version-- focus on them and use the text to fill in rough spots.

What is the central dogma? How would a neuropeptide get made (in general terms)? What are the basic parts of DNA, RNA, and proteins? What is the difference between hnRNA, mRNA and tRNA? How does RNA polymerase work and what does it make? How does it know where to start and stop? How does a ribosome work and what does it make? How does it know where to start and stop? If the DNA in every cell in your body is the same why don't your adipose (fat) cells secrete epinephrine? If the DNA contains all of the information why doesn't the ribosome just 'read' it? Why have intermediate steps?

  R

More protein manufacturing (finish translation)

Sorting the neurotransmitter-- some use direct access

CBI 2.4 Amino Acids 335-352 stop at 'There are...' 619-620 'Carrier..' to 'Active..'
CBI 6.4 mRNA translation
ECB 7.5 and 7.6
364 Fig 6-90 http://www.bio.davidson.edu/people/kabernd/cb/
restricted/figures
/filingv.html

Now the neuropeptide is made or the tyrosine has been enzymatically modified into epinephrine and they end up in the cytosol. How does the polar molecule get into the synaptic vesicle? Direct access provides one method. (we will see others) What is active transport? Which types of signaling molecules may be more likely to use this approach? Which cellular membrane would the molecule be actively transported through?
Bipolar disorder sufferers experience periods of varied neuronal transmission. How could problems in neurotransmitter synthesis or delivery be responsible for this phenotype? In order to get the mania and the depression what would have to happen? (This is where you get to add to science-- the molecular basis of bipolar is not known. What avenues of research look promising to you? Which ones would you put on the back burner?)


10/16 T Fall Break: No Class
  R

Protein #2: Neurotransmitter receptor
How is it made? packaged? Intro to vesicles

342-344 to end of page CBI 6.5 Ribosomal Elongation Factor 689-690 'The Endoplasmic Reticulum' to end of page
Fig 6-62 (342) CBI 12.3 Ribosome?ER translocator Fig 12.42 (695)
666-667 'Signal...' to 'Most Membrane...' 692-694 'Rough...' to 'A Signal...'
Fig 12.40 (694)
694-702 'A Signal' to 'Most Proteins...' Fig 12-45 (697)

Neurotransmitter receptors need to be part of a membrane-- they are integral membrane proteins (also called transmembrane proteins). Like other proteins the receptors are made in the cytosol. How do they get into the membrane? How can they be made in an aqueous environment and end up with parts in the hydrophobic membrane and parts on either side of that membrane? A simple 'door' through the membrane can't be enough. (A door to a room does not let you become part of the wall). The process of inserting membrane proteins is known as protein translocation and is part of protein sorting. How are the 'right' proteins chosen for translocation? (Said another way-- why is a neurotransmitter receptor synthesized in the cytosol and translocated but the parts of a trimer G protein are synthesized in the cytosol and remain there?) When does translocation take place? Does it occur during translation or after the protein has been made? Is there translocation machinery on every membrane or can newly made membrane proteins only get into a membrane at certain organelles? Moving a protein across a membrane is thermodynamically unfavorable (to say the least) where does the energy come from that powers translocation? Be able to describe the translocation mechanisms and think about how you would be able to tell which one was being used (what are their similarities and differences).

Thursday Oct 18th 4:30PM
Dr. Beth Hiltbold, Wake Forest University
Topic: Dendritic cells fighting intracellular pathogens (Title TBA)

10/23 T Continue discussing last reading
 

R

How are the packages delivered? Secretion and the SNARE hypothesis

711-724 stop at 'SNAREs May...' 737-738 stop at "Matrix...' 757-761 stop at 'Regulated...'
CBI 13.1 Clathrin
ECB15.8
764-5 (all)  

Now that the receptor is in the membrane and the neurotransmitter is in the synaptic vesicle how do we get them to the right place? Why do synaptic vesicles fuse with the plasma membrane of the nerve terminal and not with the plasma membrane at the nerve cell body? Why don't they fuse with the membrane of the lysosome? The 'easy' answer is that synaptic vesicles only fuse at the synaptic terminal because that's where the neurotransmitter is supposed to go. Releasing it anywhere else would be wasteful and possibly detrimental. The translocator gets the receptor 'into' the ER membrane but vesicles are needed to get the membrane protein to the dendrite membrane where it can function correctly. How do these vesicles form? How do they end up containing the right content? (things that are supposed to be delivered, not ones that should stay in the ER)? What is the difference in regulations level between constitutive and regulated secretion.

10/30 T

Monday Oct 29th 4:00PM
Dr. Julie Goodliffe, UNCC
Topic: Genomics and Drosophila (title TBA)

Continue discussing last readings

 

R

Other types of intracellular traffic.

746-756 'Transport...' to bottom of 756

Of course cells don't only exocytose they also endocytose, recycle and transcytose proteins. All of these forms of traffic use vesicles. How are the vesicles similar and different? Given any experimental method you wanted could you tell them apart? If no--why not? If yes--how?

How do the packages get there? Molecular roads and infrastructure.
Vesicles could just float around until they bump into the right membrane, but they don't. The speed of vesicular traffic testifies to the fact that brownian motion and diffusion aren't controlling the ways that vesicles move. Perhaps that's where mutations causing bipolar come into play--metaphorically speaking, maybe the parts are fine but the delivery trucks go on strike periodically or the roads are bad. What are the molecular road and delivery trucks? The cytoskeleton and molecular motors that move vesicles along the cytoskeleton.

CBI 1.2 Crawling Amoeba
ECB 2.1

907-928 (all)  

Look at the video clip as an example of how the cell can change shape. Think about the kinds of structures that would be necessary to maintain those shapes. What are the components of the cytoskeleton? What do they have in common and how are they different. Are they rigid or flexible? Are they built once, remodelled sometimes or constantly changing? Why is this property important to cellular function? How could it effect cellular function if this property was altered? (Increased flexibility or increased rigidity)

(Paper #2 and questions are now available on Blackboard. Questions are due on Wednesday 11/7 BEFORE our discussion of the paper)

11/6 T

Molecular roads and infrastructure.
Regulation of cytoskeleton-- building and maintaining the roads and
the engines that move vesicles
Reading

929-944 stop at 'Cytoskeletal...' CBI 16.2 Microtubules and ER Dyn. CBI 16.4 Beating Heart Cell CBI 18.3 Mitotic spindle in a Fly embryo
949-961 stop at 'Muscle...'

CBI 16.5 Organelle movement

CBI 16.8 Crawling actin CBI 16.6 Myosin CBI 16.7 Kinesin


The cytoskeleton acts as both structural support and roads for the cell. The video clips illustrate the dynamic nature of the cytoskeleton. Also note how the heart muscle cell not only changes shape but is able to generate force through its shape changes. The leading edge of the migrating cell in 16.2 is extended by microtubules pushing it forward-- but the microtubules aren't stable. They grow and retract. How can that be? How can you have a constant structure if the skeleton keeps falling apart? How can vesicles end up in the right place if the roads break down? What are the processed of dynamic instability and treadmilling? How are they similar and different? Why is this instability important to the cell? Do cytoskeletal elements and the regulation of their stability seem like a good direction for study?

Now we have a little better understanding of the cellular 'roads'. Now we turn our attention to the engines that drive along those roads-- molecular motors. As with most cellular machines, molecular motors are made of proteins. These proteins have certain specificities and enzymatic activity that are important for their function. What are the motors? How do they 'know' what cargo to bind with and what roads to move along?
Do molecular motors seem like a plausible candidate for the cause of bipolar disorder? Why or why not?

  R

questions due Noon Wednesday 11/7

Discussion of Paper #2: C. McCann, et al. (2005) Peptide tags for labeling membrane proteins in live cells with multiple fluorophores. Biotechniques 38

11/13 T

Finish Article Discussion
The latest on Bipolar
Wrap up:
Review 2 available by 8:30am (Due Friday 11/16 before 4pm)

R

Thursday Nov 15th, 4:30PM
Dr. Rik Myers, University of Miami
Topic: Genetic redundancy and metabolic robustness (title TBA)
(Assoc Dean of U of Miami School of Medicine will be joining Dr. Myers)

 11/20 T

Introduction to Case Study 3: Introduction to Werner's Syndrome

http://www.biology.arizona.edu/cell_bio/tutorials/
cell_cycle/cells2.html
983-986 stop at 'The Cell-cycle Control...'
Werner's syndrome is a progeriac disease. Individuals that suffer from it undergo the 'symptoms' of rapid aging and have a significantly shortened life-span. To discuss aging we must first understand the normal cycle and control of cell life--the cell cycle.
  R

Thanksgiving Break

11/27 T

Life of a Cell: Cell cycle and its regulation

990-1009 'Components...' to end of 1009. CBI 17.3 Cdk2 1014-1023 'Extracellular...' to 'Intricately...' CBI 23.1 Breast Cancer Cells

Today's reading covers many of the details of the cell cycle. With so much riding on its correct completion you can understand why the cycle would have many checks and balances. What are some of the ways that a cell determines it is 'ok' to go through the cell cycle? How do positive and negative feedback play a role in the process? What kinds of enzymes are involved? If a CDK need a cyclin in order to be functional why aren't these proteins found in 1:1 ratios? (Are there more CDK's or cyclins? How do they work together to regulate the cell cycle). The Breast Cancer video clip illustrates what happens when lack of control leads to too much cell division. In Werner's there seems to be too little. Cells die and are not replaced leading to death of the individual. Its a delicate balance, too much or too little and problems occur. In class we will discuss the theories that connect cell cycle regulation to the aging process.

  R

Final exam 'prequestions' will be emailed to you on Thursday

Telomere theory of Aging

1017-1019 'Human...' to 'Extracellular...' CBI 5.4 DNA replication fork End replication problem
206-207 'Each...' to 'DNA Molecules...' CBI 5.1 DNA Helicase 263-266 to end of 266
12/4 T

No class (attending Amer Soc Cell Biol Meeting)

Prefinal question list available on course website.

Paper 3: Austriaco, Jr and Guarente 1997 PNAS vol94 9768-72
Paper and Discussion questions available on Blackboard
Discussion will occur in lab

R

Why and how do cells die? Apoptosis and Death due to damage 

CBI 17.1 Apoptosis Apoptosis 1010-1014 stop at 'Extracellular...'

10min presentations of your lab project
 

Both sections of the final exam will be emailed to you by Monday December 10th
The final is due Monday December 17th before 11am



© Copyright 2007, Department of Biology, Davidson College, Davidson, NC 28035. Send comments, questions, and suggestions to: kabernd@davidson.edu