Kicking off Unit 6

This has been the semester from h*ll.  Have I already said that?  Yeah, I think I have.

Last week was spring break, which was absolutely lovely.  Prior to spring break, we flew through Unit 5 in about 4 days.  The students learned about the mole, they learned how to do conversions with Avogadro's number, and they learned how to do molar mass conversions.  No real labs, and I barely used the modeling curriculum-- just previous year's PowerPoints and grill & drill practice worksheets.  We ran out of time before spring break to do percent composition and empirical formulas.  I will pick them up at some other point in time... IF there is time.  The EOC is in 4 weeks and we have so much to do.

Today we began Unit 6 with a "charge" lab.  I chose not to do the Sticky Tape Lab.  In my modeling workshop, I remembered that lab being extremely time consuming.  We DO NOT have time. Instead, I adapted a lab I have used in the past called "Electrons on the Move," which can be completed in less than 30 minutes.  Obviously I did not call it that this time around-- we referred to it as "The Charges of Matter" lab.

Basically, it's a static electricity lab composed of six stations.  Students rub balloons and plastic objects on fabric and see the attractions and repulsions.

Before the lab, we discussed Democritus and Dalton's atomic theories, then I told them there was another scientist named JJ Thomson who added to the atomic theory based off his work with electrical charges.  We discussed the idea of charges.  Where have we seen positive/negative charges or ends of something in the lab so far (batteries, magnets)?  We discussed how like charges repel, opposite charges attract.  They were told the purpose of the lab was to determine if the objects in the lab had charges.  They were to draw a before and after sketch of each station, then assign charges to the objects.

Each lab group was assigned a single station to whiteboarded a verbal explanation and a diagram, both of the charges and of the particles.

Some examples (missing station 6):

Um... sort of not really

A little better

Not too bad

At least they were thinking about it

As a class, we came to the conclusion that:
1. Matter can have positive, negative, or neutral charges.
2. The charge of matter can change.
3. In the lab, the charge changed without changing the particles.

We didn't go into details on "positive" and "negative" yet.  Most have at ton of misconceptions in that department, but hopefully we'll clear them up tomorrow when we introduce the idea of electrons.

I sent them home with the online notes activity about JJ Thomson's experiments included in the curriculum.  It links students to A Look Inside The Atom to learn about JJ Thomson's cathode ray experiments.  I hope to heck that at least some of them attempt it so we can move on quickly.

Unit 5 Review and Biology v. Chemistry

Last September in our final modeling workshop, one of the university professors helping out with the event had another fabulous quote:  biology requires students to understand more advanced chemistry than the students actually learn in general chemistry.

As someone who teaches both biology and chemistry, this quote rocked me to the core-- because it is absolutely true!  The state of Tennessee is going to test my students at the end of the year on topics such as hydrogen bonding, polarity of molecules, and the structure of organic molecules.  When will these students see these topics again?  Hydrogen bonding and polarity are glossed over in high school chemistry.  Many of them will never see organic chemistry ever again and do quite well for themselves regardless.

This observation does make a good argument for inverted curriculum, which I had previously been rather indifferent about.  I spent this entire unit wishing my students had a stronger background in chemistry.  When you are trying to teach a student something like how a phospholipid works, a former chemistry student would at least have some prior knowledge of polarity to fall back on.  When they are trying to predict whether or not ions will diffuse through the cell membrane, at least they would understand something about ionization.  The list of benefits are endless.  Instead, I'm forcing my students to memorize concepts when they don't have the background to fully understand these concepts.  I definitely talk about chemistry more in biology than I talk about biology in chemistry!

Anyway...

Today was review day, since our unit 5 test will be tomorrow.  There were a lot of wonderful activities in this unit that I just flat out didn't have time to do, like "The case of the Somalian Ivory Poachers" and the gel electrophoresis simulation.  Both looked like fun and both had great real world connections.  I'm bummed we didn't get to do them.

What we did do:

-Modified introduction to cells/microscopes with prepared plant cell slides, cheek cell wet mounts, and pond water wet mounts.

-Modified Diffusion/Osmosis Lab activity with dialysis tubing, as well as demos with scented body spray and food coloring in water.

-Notes on Cell Membranes/Passive Transport*

-Exercise 1 with associated textbook reading

-Osmosis in hypertonic/hypotonic/isotonic solutions rubber egg lab

-Exercise 2, modified to match lab

-Active Transport textbook reading

-Notes on Active Transport*

-Documentary on Rosalind Franklin's role in the discovery of DNA's structure (in place of DNA Webquest since we couldn't access the computers this day)

-Nucleic Acid Article Reading/Notes on Nucleic Acids*

-What is a protein? Group research paper activity

-Protein Synthesis with Words lab activity

-Webquest:  Protein Synthesis

-Notes on Transcription/Translation/Mutations*

-Exercise 3 Transcription/Translation

-"Little Mito:  The story of where he came from" and associated writing assignment

-Enzymes Notes*

-Toothpickase Enzyme Lab

-How does a cell function as a whole?  Cell Analogy activity

* instead of having a "model," I have fallen back to using PowerPoints for notes.  How can I get back to the concept of a model for each topic, instead of just dictated notes?  Is it a problem to keep falling back on these PowerPoint presentations?  I'm not sure.

I really, really, REALLY liked the cell analogy activity as a review before the test tomorrow.  I know this is not an activity unique to modeling, but I had never done it before.  Plus, I was feeling like despite this unit being called "Cell Structure and Function," we talked very little about the cell on the whole.  This brought it all back together and really made the students think about ALL the organelles working with each other.  I have to say, the biology modeling curriculum is organized in such a way that it builds upon itself near flawlessly.

My first two blocks were pretty boring with their analogies, mainly sticking with easy analogies like factory or school...

My last block went wild.  They were doing things like Star Wars, Football Teams, iPhones... and then this wildly inappropriate, yet absolutely hilarious analogy comparing a cell to "da hood."

I would have been more concerned about this if it hadn't been created by a bunch of suburban kids who have only seen this stuff on TV.  Instead, we all had a good laugh as they tried to explain to us how "da hood" works.

Unit 5 Reflections: Protein Synthesis with Words

When I did my modeling workshop, one of our leaders had a great quote.  He said that his first period class deserves a refund every day.  It doesn't get much more true than that... especially for me today!

Examples of the cards to be created for the Protein Synthesis with Words activity.  Tip:  it takes a good hour to create and set up this activity.

After the debacle that was first block today, I was pretty well convinced that the Protein Synthesis with Words activity was a worthless piece of garbage.  Luckily, the activity got better as the day progressed.  My first block students are my only non-honors class, so I do have to "help" them along a little more than my honors classes, but I supposed I killed them with intended kindness today.  We reviewed the differences between the nitrogenous bases in DNA and RNA, we practiced matching the complementing bases, we read through the activity together, I assigned roles, and I even modeled how to do sentence #1 for the class.

...and then the proverbial shite hit the fan.

They couldn't figure out anything.  They were making mistakes.  They were yelling at each other for messing up.  Only a couple groups were able to "synthesize" any protein sentences.  We all left frustrated and never even got to white board or discuss the lab.

So next block, I decided not to tell those students much of anything to see if that worked better.  We still reviewed the nitrogenous bases of DNA and RNA and how to match complementing bases, we still read the instructions together, I still assigned roles... and that was it.  They were all able to figure it out on their own.  The activity went brilliantly the rest of the day.

After about 30-45 minutes of "decoding" the sentences, I had everyone stop where they were.  I gave them the correct answers, since quite a few groups had at least one sentence they were stuck on.  I had them create white boards with a verbal and diagram explanation of how proteins are synthesized. (I forgot pictures!)  And I believe they all walked away with a conclusion than DNA in the nucleus is turned into RNA and used to assemble proteins in the ribosomes with the anticodons determining the amino acid sequence.  I did not introduce the words "transcription" or "translation" yet.  Looking ahead at the lesson plan, I kind of wish I had at least introduced the concepts of mRNA, tRNA, and rRNA, but we simply ran out of time.

Tomorrow, we will be doing a WebQuest on Protein Synthesis to learn the details of Transcription and Translation and create our "notes" (model).

I'm not quite sure how much I'll revisit the activity with my first block... I may or may not try to have them whiteboard their conclusions.

When I do this activity again, and I will, I definitely will remember to back off and let them figure it out on their own...

Unit 5 and the benefits of "lab first"

I'll admit, I may have strayed from the central theme of modeling instruction-- "the model."  I'm still struggling with the concept of the "model" for biology.  Our models just end up being, well, notes.  I realize I haven't even been using the word "model" this semester as I did in the earlier units.  I should try to improve upon that and re-incorporate the concept of the model.

But I have become an ardent fan of the "lab first" style of teaching science.  I don't think I'll ever go back to a traditional lecture/lab structure.  One of many teachers' criticisms of labs is that the students often miss the point.  I frequently saw this myself:  you'd cover a topic like osmosis and diffusion, then go into the lab supposedly to reinforce the concepts.  The problem was the students often couldn't put two and two together and just ended up going through the motions.  I'd frequently skip discussing the lab in lieu of just having them answer questions about the lab, which they often answered poorly.

The benefits of switching to lab first are innumerable.  Two of the biggest are that it forces you to actually discuss the lab results and it gives the students something tangible to make connections with.  The only downside is that I occasionally get a snarky comment from a student who thinks he/she knows it all ("I don't get how this is supposed to show us ______.").  But even those are rare and have greatly decreased.

For example, this week I have been covering cell membranes and transport.  Hypertonic, Hypotonic, and Isotonic are terms students traditionally struggle with.  So earlier this week, we made rubber eggs (instead of the potato lab) that were ready for today:

From left to right, eggs soaked in distilled water, a mixture of corn syrup and water, and corn syrup alone

The students were able to talk out what happened to the eggs and form a conclusion based on what they already learned about osmosis.  All I had to do was introduce the new terms.  The concept of "hypertonic" is a million types easier for a student to grasp when they are quite literally grasping a deflated egg in their hand.  And when they got confused, I just reminded them to think about the eggs.

I gave my classes Unit 5 Exercise 2 today (I replaced "potato" with "egg").  Several of my students told me it was "easy."  That's nice to hear for a change!

Unit 4 Wrap Up

Remnants of our photosynthesis lab

You know that feeling when everything hits the fan?  That's been my past couple weeks.

I thought Cellular Respiration and Photosynthesis went well.  My test results from last week said otherwise.  Looking back, Unit 4 was WAY too much material and way too diverse of material.  I was aware of this while I was teaching, but I didn't realize quite how significantly it impacted my students until the test.  Grades were still good, but class averages were lower than usual.

In my darling standard biology class, the 50:50 split was worse than ever.  Half the class had high As, two Cs, and the remaining students failed and failed badly.  For those students who failed, they temporarily lost their lab privileges and in lieu of lab completed an open notes re-test.  The strategy seemed to help, re-test grades were much improved, and I was able to work one on one with many of them while the other students were working on a dialysis tubing lab.  I realized two things working with the students individually:  1) just how overwhelming this unit was, and 2) the average sophomore in high school knows NOTHING about plants.  I mean nothing at all.  Multiple students said that my class was the first time that had EVER heard that plants make their own food.  I'm not sure I've ever encountered that before... but without any prior knowledge to help make connections, the process of "photosynthesis" was a billion times harder for them.  Who woulda thunk it.

In the meantime, we've started Unit 5 The Cell.  I've made some modifications due to time.  We did an intro to the microscope and looked at plant and cheek cells.  Then we did some diffusion/osmosis experiments, including perfume in air, food coloring in water, and glucose/starch in dialysis tubing.

Out of all my classes, only ONE group included "air" particles in their diagram.  Obviously this wasn't the group.

Dialysis tubing with glucose/starch solution placed in a beaker of DI water and Lugol's Iodine.  Fun fact- glucose didn't diffuse through the tubing as it should have this time around. I inadvertently reinforced a misconception in all my students' minds.

Not the strongest conclusion ever... 

We also set up a "rubber egg" osmosis lab instead of the potato lab included in the teacher notes.  Meh, I wasn't feeling the potato set up.

We have, count 'em, less than FIVE more weeks to get through:  transcription/translation/protein synthesis, enzymes, mitosis, meiosis, and all of genetics.  Ouch.  Let the panic attack begin.