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# Spring 2017 Physics 131 Reminder from 4-27

last edited by 2 years, 11 months ago

Reminder from 4/27 Training for the week of 5/02 (Lab 5, Part 2)

Here are the reminders from Thursday's training.

If you think your sections need this, please consider sending them a reminder of what analysis needs to be completed before they come to recitation/lab in the week of May 2nd-May 8th.  We expect that all lab groups will have fully tracked the random and directed motion in their onion video, that they will have measured the vesicle size, and that they will have done some portion of the Excel analysis (conversions, calculations to get <r^2> vs. t and log(<r^2>) vs. Log(t) plots).

1) Recitation: Protein Stability

(Please encourage the students to work collaboratively, using the whiteboards and markers. The recitation papers are on the printer table at the back of the room.)

(Break)--Pass back graded Lab 4 reports, if you have not yet done so....

2) Lab 5, Part 2

This is the CAPSTONE lab for 1st semester, employing all the experimental skills and physics concepts we have learned in labs 1 through 4 this semester.  We will be testing students' ability to classify motion and then using the classified motion to gain a deeper understanding of the energetic workings inside a living cell.

a) Numbers I gave to you that students might ask about/want:  The maximum rate of ATP hydrolysis for a single motor protein is on the order of 300 Hz.  (Remember that I also gave you the viscosity for salt water in the TA document.)  If they have failed to measure the vesicle size from the video and no longer have this info, they can use the vesicle diameter as 2 microns.

b) Students will need to:

• Figure out how to get the average velocity of their directed vesicles (from their log-log plots or from their spreadsheet data).
• Determine whether they want to model kinesin or myosin motors (and justify the choice).
• Find the rate of ATP hydrolization.  Think about what this means for the  motor protein/vesicle.
• Find the effective viscosity.  Think about what this means for the cytosol/vesicle.
• Write a report presenting and analyzing their findings.
• Present their work to their classmates (posters).

c) You might consider directing the students to Google cytoskeletal structure images or motor protein functions to help them put the numbers they are getting into context.  If they need some help figuring out the myosin/kinesin issue, send them to the page I got the cell structure stuff from (foot-noted in the TA document, a British Cell Bio Society webpage...).

d) If students are getting very funky slopes for their log-log plots, chances are they have either made a bad conversion or done something funky in analyzing their times (I fixed a few bad slopes by tracking time analysis).  The 'random' stuff is likely to have a slope of roughly 1 or even less (random or caged).  The 'directed' stuff is likely to have a slope of 1.5 to 2 (biological to directed at constant speed).

e) Groups should be engaging in presentations for Lab 5--and there should be plenty of time for this.  If you have done presentations only once so far (either Lab 3 or Lab 4), then do the other style of presentation that your students have not yet practiced.  If you managed to do presentations in both Lab 3 and Lab 4 (and have, thus, already practices both styles of presentations), then I suggest letting your students pick which style they like best for Lab 5--let them vote on the style and let the majority vote determine what the class will do for the presentations ('talk' or 'poster' style).

f) After students have turned in their lab reports, please bring these to me in 1322 and I will scan them and get them back to you.  Your grading of these reports will need to be pretty rapid--so that you can give feedback to the students when you see them in the week of May 9th (and so that we can get complete lab scores into ELMS so that I can renormalize the lab scores by TA).

3) Other Logistics:

a) Organize and send to me your list of which students need a make-up lab (see below).  Getting your ELMS gradebook up-to-date (with both Lab scores and Recitation/Lab Participation scores) will help you get organized.  Check back through your previous score entries to ensure you have not made any mistakes or missed entering any scores.  I need your list by Saturday, April 29th--and you should update the list and email me immediately if any students miss Lab 5, Part 2.  (The make-up lab  will take place May 9th-May 11th.)  I need the following information for EACH student in your sections who has missed any week of lab:

• Student's full name
• Student's section number
• Student's email address (find this via UMEG)
• Number of weeks of lab missed--and which parts of which labs were missed

Once I have this information, I will coordinate with these students to arrange the make-up lab days/times.  Please send me the above information by Saturday, April 29th.

b) You should email me immediately if any students miss Lab 5, Part 2.  I need to add them to the email about the make-up labs.  Also, please email me if you have any extra students, too, so that I can make sure a student attending a different lab section than their normal one is not accidentally considered completely absent from the second week of lab.

c) We have our next training on Thursday, 5/04, to train for the final recitation, the surveys, and the make-up lab (which will occur May 9th-May 11th).

That's all I can think of for now.  Let me know if you have any questions or concerns.  Keep up the great work!

~KIM