Cellular Respiration Lab

 Cellular Respiration Lab with Grass Seed

This is a version of the AP Biology respiration lab that I’ve modified to be quicker and easier to accomplish in limited class time.  It also is teachers like me who realize at the last minute that they’re planning to do a lab for which a key supply is difficult to come by in a rush.  I’ve had problems a couple of times finding good seeds to use in the fall – grocery store beans have at times done a better job of growing fungus for me than of germinating.  In the fall in the midwest, the easiest and cheapest seeds to find that are guaranteed to germinate are grass seeds so that’s what I used for this lab. 

I had student aides mass out the seeds for me (into plastic petri dishes with dry paper towels cut to fit into the bottom of the petri dishes).  Then all I had to do was add enough water to thoroughly moisten the seeds (and towels) in half the petri dishes that evening before leaving school.  (Don’t forget to leave half of them dry – these are your dormant/non-germinating seeds.)  In the morning I checked the seeds again to make sure they were thoroughly moist but not too wet and continued to periodically check them until we used them in the lab. 

With this modification the lab went very smoothly and seeds begun on Monday after school were adequately germinated by mid-morning that Thursday (and perfect for the Friday classes).  I realize it’s better to keep the volume of seeds (and beads) constant in all the respirometers but most of my students fail to appreciate that subtlety and often get so wrapped up in technique that they miss the key concept – the changing oxygen volumes.  This version seemed to work well with those students.

 Cellular Respiration Lab with Grass Seed

Catalase Enzyme Activity Lab

Catalase Enzyme Activity Lab

This Catalase Enzyme Activity Lab has a technique which is easy for students (after the initial practice phase) and lets them gather multiple trials quickly and easily.  It’s powerful because it allows exploration of important biochemistry concepts while reinforcing data analysis and utilizing graphing techniques tested on state math assessments.

Each group explores one set of conditions in detail then uses the data of other groups to graph and analyze several other conditions.  I use this lab early in the year when I’m working on protein structure, enzymes, and how free energy relates to enzyme activity.  The lab utilizes filter paper disks (cut out with a hole punch to keep them uniform sizes) dipped in catalase solutions which are then dropped into hydrogen peroxide.  Students time how long it takes for the disks to rise (they rise when enough oxygen bubbles accumulate on the filter disks to make them buoyant in the hydrogen peroxide solution).  The data produced is easily graphed and analyzed using box and whiskers graphs (aka box plots).   Students are taught this graphing technique in math classes (and are tested on it on state assessments) but don’t often have the opportunity to apply them and therefore don’t appreciate their ease, elegance, and power.

Catalase Enzyme Activity Lab

Happy 200th Birthday, Charles Darwin!


Charles Darwin once wrote, “Ignorance more frequently begets confidence than does knowledge.”  With that quote in mind, I decided to compile a few of the Darwin related resources that I have recently and happily become inundated with.  So, click, read, download, listen, and watch, all the while gaining knowlege and gradually losing any confidence that you may have had… 

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Best Practice Simplified

At the EduCon 2.1 conference in Philadelphia, late this January, I came across the most profound, succinct, and employable explanation of “best practice” that I have ever seen.  I would like to make the argument that if all teachers in our schools employed this simple model, education would be revolutionized in this country.  On posters throughout one of Philadelphia’s top public schools, the Science Leadership Academy, were the following five core values, constituting what I see as the best roadmap to best practice that I have seen:  Inquiry; Research; Collaboration; Presentation; Reflection.

So often our courses focus too much on the acquisition of “important” facts” and  not enough on how to solve problems in an educated way.  I have met more than a few biology teachers who talk with pride about the way their students know all of the intermediate steps of glycolysis, and I would argue that this may not be the best use of either the teacher’s or the students’ time.  If you surveyed 100 successful adults, from custodians to theoretical physicists, and asked them whether, in the last month, they had to know any of the biochemical interactions of photosynthesis, I can not imagine one of them answering “yes”.  If you asked the same group of people whether, in the last month, they have had to collaborate, research, present, and/or solve a problem, I would be surprised if a single one of them said they had not.  If the second set of skills are the ones that successful people in all walks of life are using all of the time, would it not be best if our educational system was centered on applying those skills to our content areas, instead of trying to get as many students to understand as many facts about the content we teach?  We can argue all day about the “essential” facts within our content area, but how easily can we argue about whether students need to be able to generate their own questions, research the question, collaborate, present their understanding, and then reflect over what was learn and what else can be learned?  These are skills we use on a daily basis, and skills that can be greatly improved when they are made a daily part of the lives of our students.

Right or wrong, my litmus test for professional development is to ask whether what I have learned can be applied on Monday.  Too often with professional development, this is not the case.  With these five core values, though, it has been different.  When I returned to school from the conference on Monday, I was able to make immediate changes.  Instead of going over a homework assignment with me in the front of the class leading the review, I asked various students to go up to the whiteboard to show how to answer various questions.  Voila!  Presentation!  For work that I would typically have the students do alone, I have focused more on having students work on assignments in groups, which facilitates both collaboration and presentation for the students.  Now with various activities and tests, I ask the students to write a reflection over the experience.  “Were you satisfied with your results on the Mitosis/Meiosis Exam?  Why or why not.  Explain.”  In my Kansas Natural History class, my students have always conducted Land Use Interviews outside of class, concerning the way that people interact with land today versus 40 or 50 years ago.  This year, however, I decided to invite to our school several residents from a local retirement home to be interviewed by my students.  Perhaps I should not have been, but I was SHOCKED when I saw how enthralled my students were with the people they were interviewing.   The residents had a wonderful experience as well, and now I will be inviting these residents back so my students can present their new understandings from the interviews they conducted.  Adding this level of presentation made things so much more real for the students, and it also serves to make members of the community more aware of what we do.  We want taxpayers to collaborate with us in funding education, but we rarely bring them in and make them a part of what we do.  I argue that having students present to and/or collaborate with a wide variety of community members, on a regular basis and in a wide variety of content areas, would do more for education funding than any conceivably high set of standardized test scores that could be posted in the newspaper.  For me, this model has been proving itself no less than transformative, because it uses my content area as a means for my students to improve their proficiencies in valuable skills found in the core values, rather than an end in and of itself.  The best part from my side is that, to incorporate it, I only have to analyze my lessons through the lens of five simple core values.

One thing I am noticing with this model, however, is that students often do not like it.  They actually prefer to have facts spoon fed to them because they are a product of the system that is educating them.  It is harder to ask questions (inquiry) than it is for the questions to be assumed and the answers given to you.  All too often, we have taken kids from four-year-olds who are constantly asking “how” and “why”, to young adults who think that all of the interesting questions have already been asked and all of the important facts are already known.  There is not a knowledgeable researcher in any field who thinks this is the case.  When you ask students to ask questions about what is going on in a drop of pond water, they ask, “what do you want me to ask?”  When you ask students to reflect on their experience in the previous unit, they ask, “what do you want me to talk about?”  This frustrates teachers, but it should not because the students are only doing what they have been taught.  I believe there is a better way of educating students from kindergarten through high school by focusing heavily on these core values, a way that could make those types of questions the exception rather than the norm.

My last thought on these core values is that they should be used as a model for teacher professional development as well.  We, as teachers, know in which areas our students are weak, and professional development time should be used for teachers to bring to light these areas (inquiry); study ways they can be addressed (research); talk with each other, community members, and other experts about solving the problem(s) (collaboration); present our findings to each other, administrators, school boards, and legislators (presentation); and then evaluate the success of the plan (reflection).  I believe that coupling these core values with continued learning in our content areas (teacher knowledge of content being a key constituent in quality teaching) would be the most useful, beneficial, and enriching professional development that most of us will have ever experienced.

Thanks for allowing me this time to reflect.  If you would like to collaborate, I would love to delve further into this issue.  If we discover anything great, maybe our inquiry will lead us to new, exciting questions or maybe we could present something we discover at a conference someday.

Celebrate Darwin’s Birthday at Linda Hall Library

When:    Thursday, February 12th, at 5:00pm
WhereLinda Hall Library (Google Map)

This free event is open to the public.  It will include a birthday cake, special viewing of first edition copies of the Origin of Species and The Voyage of the Beagle, and a brief presentation “Celebrating Charles Darwin by UMKC Professor Bill Ashworth.


Following the party guests are encouraged to attend our One Book event featuring a biography of Darwin’s most influential work, written by the eminent Darwin scholar Janet Browne.   Darwin’s Origin of species : a biography is a highly readable introduction to one of the most influential scientific theories of all time.   The book discussion will be from 6 p.m. to 8 p.m. in the library’s Main Reading Room.  This event is free and open to the public.   Reservations are recommended as seating may be limited.  To ensure your seat, please R.S.V.P. by emailing Scott Curtis or calling (816) 926-8739.