TBT: Protein Synthesis Models (In My Classroom)

EDITOR’S NOTE: THIS POST ORIGINALLY APPEARED IN FEBRUARY 2015 AS THE 3RD INSTALLMENT OF THE “IN MY CLASSROOM” SERIES. KABT MEMBER IN EXILE, CAMDEN BURTON, SHARED THIS ACTIVITY WHERE HE HAD HIS STUDENTS COMPARE AND CRITIQUE MODELS. ENJOY THIS KABT CLASSIC!

Thanks to a little idea from Brad I thought I would try something with my AP Biology students this week that I saw him try with his BIO 100 students at KU earlier.

We’re currently marching our way through the mind-bending terror that is protein synthesis. So we’ve gone over the whole process a bit but to make sure we were not getting lost in the details I gave them this:

Blank central dogma 1Blank central dogma 2

Two different models of the same process. Nothing earth-shatteringly innovative but how I framed it and worked with it was unique to me. I didn’t just say it was a worksheet to complete. I framed it as 2 different models of the same process. If they wanted to use the picture in their book that was ok because the diagram in their Campbell book also looked different. What I was surprised with was how much students struggle translating [pun] knowledge across models. Students struggled with labeling processes versus structures, labeling the same structure that was differently drawn in two models, and especially when one model added or removed details (like introns and exons).

The other cool part was that afterwards when students shared their answers on the board, they had lengthy discussion about what was “right”. For example, two students argued whether the 4th answer from the top was “pre-mRNA” or “mRNA” and explained why they thought that. After looking to me I shared that by their explanations both could be right. That’s what I think was cool, students argued different answers where with the proper explanations, either could be right. So because of that, I would avoid giving an “word bank”.

Also, at the very end I created a list on the board titled “limitations” and I had them share what was limiting about these diagrams. Some thoughts were “no nucleotides were shown entering RNA polymerase”, “no other cell components were shown”, “the ribosome on top only had room for one tRNA”, “no mRNA cap or tail were shown”, and many more.

I found this exercise useful because I struggle giving students modeling opportunities (especially non-physical ones) and this was a simple way for students to get practice comparing/contrasting models while also discussing the usefulness and limitations of them.

Alright, for the 4th installment I nominate el presidente himself, Noah Busch.

TBT: Cell Museum Project

Editor’s Note: This post originally appeared in December 2015 as part of the “In My Classroom” series. The author, Andrew Taylor, is an incredible Biology teacher currently at Olathe Northwest HS. This TBT selection was motivated by a recent Tweet/Periscope storm from Jessica Popescu (mentioned in this post) regarding #CellMuseum2016. Take it away, Andrew!

Students in my classroom recently completed a project based learning unit centered around the driving question ‘How can we, as museum exhibit designers, build a museum exhibit about a somatic cell type that will engage younger audiences?’ The question came about as a collaboration between myself, Jessica Popescu, who teaches one door down from me, and the staff at the Columbus Museum in Georgia, most specifically Rebecca Bush, the curator of history. The project consisted of students working in teams of three to four. The teams first divided themselves up into specific roles and selected a somatic cell type to research and display. The potential roles each had real-world parallels in the museum industry. Role options consisted of a marketing director, a manipulative designer, an application letter writer, and a presentation specialist. The Columbus Museum emphasized how these roles relate to their real world job responsibilities in a video displayed to the students early in the project. The video also included several example exhibits within the museum and information as to what type of items the staff looks for in a museum exhibit.

The reason we decided to have students design their exhibits around a specific cell type, as opposed to just ‘animal’ or ‘plant’ cell was to help students understand the interactions, and the importance of those interactions, between different cells in a multi-cellular organism. Students had baseline knowledge of cell organelles, the cell membrane, and cellular transport when the project began.

Exhibit 1

The project as a whole was very successful. Students created a variety of excellent products, a few of which are pictured in this post. Additionally, students took pride in displaying their exhibits to students from a variety of different classrooms. Also present for presentations and ‘museum walks’ were teachers from throughout the school and various members of the administration. The students will also receive feedback on their final products from the staff at the Columbus Museum. One of the most significant signs of success to me was the way in which students generated questions throughout their research. A moment that sticks out to me occurred as a student attempting to do the bare minimum and simply draw a picture of a red blood cell (their cell type), asked the question, ‘Why don’t red blood cells have many organelles?’ This question led him down a path of discovery that led to another question, ‘If red blood cells don’t have a nucleus, then they probably don’t have DNA which is needed to make protein, so how in the world do they have a large supply of the protein ‘hemoglobin?’ Another example of a questioning attitude is drawn from Mrs. Popescu’s classroom. A group of students researching cone cells asked another group why they decided to color their cone cell model yellow when humans only have cone cells for red, blue, and green.

16

In completing the project next year, I will strive to offer students more opportunities at receiving feedback before the final displays are done. Also, while the student generated questions were awesome, my goal is to structure the project so that more students begin asking these types of thought provoking questions.

Happy holidays everyone, and now I’ll throw it back over to Brittany Roper for the first post of the new year.

TBT: Miniposters

Editor’s Note: So far this semester, the most popular single post on the BioBlog is this September 2013 peer-review piece from our blogfather, Brad Williamson. Also this is a reposting of a reposting. Blogception!  Enjoy this, and if you use mini-posters in your classes, share your experience with us in the comments!

This is a reposting of a post that first appeared on the NABT BioBlog:

Miniposter, Jai Hoyer

Background and Rationale:

Almost 20 years ago, I was fortunate to be invited to my first Bioquest Workshop at Beloit College. Maura Flannery covered the Bioquest experience in several her columns in the American Biology Teacher. These workshops challenge and inspire you as you work with a number of like-minded biology educators working on the edge of new developments. What really caught me off guard was the intensity of the learning experience. Before the end of the first full day, each working group had to produce a scientific poster presentation. This was my first, personal experience with building a poster so I’m glad that I don’t really have a record of it. I talked to John Jungck about the poster requirements—he told me that the students in his labs prepare a poster for each laboratory–rather than a lab-write up and they have to defend/present them in poster sessions. I immediately saw that a poster would help me evaluate my student’s lab experience while provide a bit of authenticity to my students doing science. That fall I had my students do a poster session that was displayed in the science hall. It was a big success with one exception. For my high school class, the experience was a bit too intense and too time consuming. It turned out that we could only work in one big poster session that year. One of the little bits of clarity of thought that comes from teaching for decades instead of years is the realization that students need to practice, practice, practice—doing anything just once is not enough. I thought about abandoning the poster session since it was too time consuming. However, I witness great learning by all levels of students with this tool. I didn’t want to abandon it. With this thought rolling around in my mind, I was primed as I visited one of my wife, Carol’s, teacher workshops. She’s a science teacher, too. In this workshop she was presenting an idea to help elementary teachers develop science fair project—a mini-science fair poster. This idea involved the used of a trifolded piece of 11″ x 17″ paper. The teachers were inputting their “required” science fair heading with post-it notes. Revision was a breeze. The teachers learned the importance of brevity with completion. They added graphs and images by gluing their graph to a small post-it. It was all so tidy, so elegant, so inviting, I probably stared a little long, struck dumb by the simplicity of the mini-poster. Once I came to my senses I realized that the mini-poster was my answer–a way to incorporate authentic peer review, formative assessment in my science classes. My high school classes could be like John’s college classes.

Making Miniposters

Over the years, mini-posters have evolved into the following. We take two, colored (for aesthetics file folders, trim off the tabs and glue them so that one panel from each overlap—leaving a trifold, mini-poster framework. Each student gets one of these. For these posters we go ahead and permanently glue on miniposter-headers that include prompts to remind the students what should be included in each section. Later, they can design their own posters from scratch. The image at the top of the page and the ones following will give you an idea. By using post-it notes the posters can easily be revised and we also reuse the poster template several times over the year. Don’t feel that you have to follow this design–feel free to innovate.

Implementing Mini-posters:

Defending the Miniposter–Presentation

Defending the miniposter:
For the first mini-poster experience, I give my students as much as a class period to work up a poster after completing an original research investigation. (We do quite a few of these early in the school year with others periodically throughout the rest of the year). Sometimes poster work is by groups and sometimes by individuals. Once the posters are ready, the class has a mini-poster session. The class is divided up in half or in groups. Half the class (or a fraction) then stays with their posters to defend and explain them while the other half play the part of the critical audience. To guide the critic, I provide each “evaluator” with a one page RUBRIC and require them to score the poster after a short presentation. I restrict the “presentation” to about 5 minutes and make sure that there is an audience for every poster. We then rotate around the room through a couple of rounds before switching places. The poster presenters become the critical audience and the evaluators become presenters. We then repeat the process. By the end of the hour every poster has been peer-reviewed and scored with a rubric–formative assessment at its best. The atmosphere is really jumping with the students generally enjoying presenting their original work to their peers. The feedback is impressive. At this point I step in and point out that I will be evaluating their posters for a grade (summative assessment) but they have until tomorrow (or next week) to revise their posters based on peer review—oh, and I’ll use the same rubric. The process works very well for me and my students and my guess is that it will for yours as well. You’ll naturally have to tweak it a bit—please do. If you find mini-posters work for you, come back here and leave a comment.

The images are from our UKanTeach Research Methods course first assignment—a weekend research investigation. Thanks to the Research Methods course for the images.

Another Sample Miniposter: Artificial Selction of Trichomes in Fastplants

Here’s a file that illustrates what a Sample-miniposter might look like constructed in MS Word.

Links to websites for advice on making scientific posters:

http://www.swarthmore.edu/NatSci/cpurrin1/posteradvice.htm

http://www.ncsu.edu/project/posters/NewSite/index.html

http://people.eku.edu/ritchisong/posterpres.html

http://www.tc.umn.edu/~schne006/tutorials/poster_design/

TBT: Spinach Chloroplasts

Editor’s Note: This post was originally published in September 2014 by our resident tinker, Michael Ralph. I think he was successful in staining chloroplasts, how about you?

I was pondering how to get a good look at plant cells with low cost, and I thought about Brad’s work with onion root tips in visualizing mitotic cells. Check out his original post here. The thought occurred to me that the fixative should dissolve inter-cellular connections in leaf tissue the same as root tissue, so I gave a section of grocery store spinach tissue the same 6 minute warm fixative bath. The tissue flattened nicely (more or less), but I couldn’t see much in the way of cell definition. Sticking with the theme, I grabbed the aceto-orcein stain because it was already handy. Here’s what I saw:

Spinach Cells - Aceto-orcein stain

Spinach Cells – Aceto-orcein stain

The remarkable definition in the organelle structure was surprising. Aceto-orcein binds DNA, so what would produce such well-defined structures that contain DNA. How about chloroplasts?

Plagiomnium ellipticum cells with visible chloroplasts.

Plagiomnium ellipticum cells with visible chloroplasts.

Let me know in the comments section:  chloroplasts or not? Alternative explanations?

TBT: Fastplant Growing Tips

Editor’s Note: So, Brad Williamson is a pretty big influence on science educators here in Kansas and across the country. Here is a post he originally put on the BioBlog in August 2013. Fastplants are a good way to teach genetics, botany, evolution, ecology… maybe it would be easier to say they are a very robust model organism. 🙂   Enjoy, and let us know if you plan on using Fastplants this school year!

Since many AP Biology teachers are trying to grow Fastplants for the first time, I thought I’d do a few blog posts that follow a generation of Fastplants in my lab.  When I was in the high school classroom I always had a surplus of seed stock available because I was always growing the plants.  Now,  I just grow them occassionally because I think it is fun and also to provide starter seed stock for the new biology teachers that graduate from our UKanTeach program.  Back in July I was fortunate to travel up to the University of Wisconsin for another Fastplant workshop.  Paul and Hedi had Fastplants growing in a number of different types of containers

but I was particularly interested in the deli/discovery cup growing systems because they are very close the the technique I used to use in my classes back when film canisters were available.

The water reservoir (the deli container) can be used to also deliver soluble fertilizer so there is minimal care needed.  These containers are a bit small for weekends so I chose to use 16 oz. containers.

I returned from Wisconsin with some new ideas to try out as well as some seed.  Note that I brought the seed back stuck in tape.  We used the tape to pick the seed up and folded it back over itself to seal the seed in after making a couple of folded over tabs on the end.

You’ll find a description of this technique in several of the resources on the Fastplant website:  http://www.fastplants.org/pdf/growing_instructions.pdf

In the mean time one of my former students asked me about growing Fastplants so I decided to go out and get some more current cost estimates for supplies.  Assuming you have a light source but otherwise are starting from scratch here is what I found.

Soluble fertilizer from a local garden store:  20-20-20 with micronutrients

Artificial seed starter mix soil:

or a larger bag:

Deli Growing containers from Party America or Party City:

along with lids:

The portion cups from Party America cost about $3.50 per 100 1.25 oz. cups.  I already had quite a bit of yellow braided nylon mason twine from Home Depot so I don’t have a cost for that.  The neat thing about this system is that the individual cups can be moved about and that module based system is pretty easy to manage in a classroom.  I also purchased a can of Flat Black Spray Paint (one coat) that I used to paint the deli containers and lids to hopefully reduce algae growth in the water reservoirs.

I marked and cut 1 and 3/8 inch diameter holes in the lids to hold the cups.  I purchased a 1 and 3/8 inch spade bit to do this for about $5.  The holes are cut very carefully and slowly by running the drill backwards or counterclockwise.  In that way the bit just kind of scratches its way through the thin plastic of the lid.  Going in the forward or clockwise direction will likely lead to different levels of disaster—the bit is not designed to cut into such thin material in the forward direction.  If you drill that way you’ll just tear up the lid and likely not produce any holes that will work.

Marking the hole locations with a paper template.

Carefully drilling in reverse to cut the holes:

I added 250 ml of dilute fertilizer solution to each deli system.  I mixed the 1 measure (a full bottle cap from a 20 oz. soda bottle) fertilizer in 1 liter of water and then diluted that stock solution 1 part stock solution to 7 parts water.   I also drilled 1/8 inch holes in the bottom of the 1.25 oz. portion cups, added a 6 inch length of twine to serve as a wick, added moist soil mix to the cups to get ready to plant.

You can see the bluish fertilizer in the systems to the left and the wicks extending out of the cups on the right.  I moisten the soil so that I can work with it in a gallon plastic bag by squeezing water into it.  You can see the bag at the top of the tray.  Before I place a cup of soil into one of the systems I first make sure that the wicking system is working.  To do that I gently poured water from the pitcher in one of the cups until water was dripping from the wick.  This ensures that the soil is moist as well.  Once the water was dripping from the wick I transferred the cup to one of the growing systems.

I then planted 4-6 seeds in each cup (I will trim this back to only two plants in each cup in about a week).  The seeds were simply dropped onto the surface of the moist soil.  They are not “planted” beneath the surface.

At this point I added a little bit of horticultural vermiculite to the surface of each cup.  I got this tip from Paul W.   You could sprinkle a little bit of soil at this point but vermiculite helps the germinating plant to escape its seed coat.  I did not include the vermiculite in the costs above but I imagine it is around $8 for a small bag that will last for years of classroom plantings.

The systems then went under the lights.  Notice how close I have positioned the lights for now.

Day 0.

Day 1:  No apparent change:

Day 2:  We have germination

Day 3:  Most of the plants have germinated.  The cotyledons are expanding.

I’ll continue to report on this round of growing Fastplants.

BW

TBT: Teaching Genetics in the 21st Century

Editor’s Note: Though not planned this way, let’s make it two in a row for Eric Kessler. He originally posted this in July 2012. With many of us starting to plan for the next school year, now is the perfect time for an article like Dr. Redfield’s. You may not agree with everything therein, but it is definitely thought-provoking. After reading the PLoS article, let us know what you think in the comments and we’ll get this conversation started. -AMI

Read this PLoS article

And the developing comments.

20120707-082102.jpg

TBT: Synthetic Biology (July 2010)

Editors note: This post on Synthetic Biology was originally published on the BioBlog 18 July 2010. While he at one point mentions that he doesn’t “pretend to be an expert” on SynBio, author Eric Kessler has gone on to do some amazing work with his students in the field. Somethings have changed in six years (here is a story by Ed Yong from March 2016), but please enjoy this look back into our archives. 


The 21st Century Prometheans?

A little over a year ago, Brad posted a link to a survey on Synthetic Biology.  Although it appears that little has fundamentally changed since then, this burgeoning field, along side nanotechnology, has become front page news, and will hopefully become a topic of conversation in your biology class in the near future.

I don’t pretend to be an expert on Synthetic Biology but I thought a few resources may provide you with enough background knowledge to approach the topic with your students this year.  Maybe they could use this post itself as a springboard for discussion or more research.  The post is in three parts, each accompanied by some thought provoking quotes from Mary Shelley’s Frankenstein…

Early Years and Standford’s Drew Endy

In these links you will will find a reference to one of the first papers in the field, a few comic responses to the field, and links to two YouTube videos (originally TED Talks) of Drew Endy explaining the difference between Synthetic Biology and the more standard and familiar recombinant DNA and genetic engineering technologies.

“The world was to him a secret which he desired to divine. Curiosity, earnest research to learn the hidden laws of nature, gladness akin to rapture, as they were unfolded to him, are among the earliest sensations he can remember . . . It was the secrets of heaven and earth that he desired to learn; and whether it was the outward substance of things or the inner spirit of nature and the mysterious soul of man that occupied him, still his inquiries were directed to the metaphysical, or in it highest sense, the physical secrets of the world.”

  1. Synthetic Biology: Engineering Escherichia coli to see light (November 2005)
  2. Nature’s comic on Synthetic Biology (November 2005)
  3. The Story of Synthia – another comic look at synthetic biology
  4. Synthetic Biology Organization with a press link to numerous popular critiques of synthetic biology
  5. SEED’s Cribsheet on Synthetic Biology (July 2010)


(June 2007)


(December 2008)

Venter creates the News & President Obama’s Responds

“There was none among the myriads of men that existed who would pity or assist me; and should I feel kindness towards my enemies? No: from that moment I declared everlasting war against the species, and, more than all, against him who had formed me and sent me forth to this insupportable misery.”


(May 2010)

  1. The President’s Emerging Technologies Interagency Policy Coordination Committee’s Inaugural Meeting (May 2010)
  2. NPR Story, Presidential Panel Scrutinizes Synthetic Biology (July 2010)

Resources for those interested in Doing some Synthetic Biology

The following resources are for entering the field of Synthetic Biology.  The first link will introduce you to an annual competition used to motivate undergraduate teams of students to design and engineer novel pathways in E. coli.  If you search around, I think that you’ll find that there has been a single high school team involved in the competition before.  Some of university sponsors are quite interested in developing a kit to introduce students to the methods synthetic biology.

  1. iGEM 2010
  2. Authentic Teaching and Learning through Synthetic Biology based the E. coli engineered to sense light
  3. The BioBricks Foundation
  4. Registry of Standard Biological Parts
  5. BioBrick Assembly Kit from New England BioLabs

“‘The labours of men of genius, however erroneously directed, scarcely ever fail in ultimately turning to the solid advantage of mankind.”