One of the coolest things about the new AP Bio curriculum is the focus on student inquiry. Step away from the teacher speak and that simply means that students get to spend days designing labs and engaging in something that resembles real science. As a teacher it is really fun for me to step back and see what they will come up with in terms of experimental design, data collection, and analysis. This year's AP Bio class doesn't know how good they have it. No more trying to bang our way through a "cookbook" lab in a single day.
Reflecting on last week's (8/27-8/31) festivities, both of our writers, Alana Lee and Asia Johnson mention some of their discoveries about a special Jello recipe. So, without further delay, here is your weekly installment of the weekly reporter. As a side note, I would encourage you to check out the personal blogs of each student. Their name serves as a link.
This week we didn’t have to watch any daily videos, but we completed a lab on Osmosis and Diffusion. On Monday we had to do Comprehension Checks 7.4 and 7.5 in groups and discuss them. We also learned and took notes briefly on active and passive transport. Active transport is using energy to go against the concentration gradient, whereas passive transport kinda goes with the flow, with the concentration gradient. There are other types of gradients including electrical and chemical (self explanatory). We also learned about two electrogenic pumps, proton and sodium potassium. With cotransport, Mr. Kite used the expression “You know a guy, that knows a guy”, which basically means that in order to get in the ‘club’ or wherever, you need to go in with another molecule, like a carb or lipid. Monday night’s assignment was to complete the pre-lab questions for the lab that we would start Tuesday. We started the lab with Procedure #2 in which we chose 3 pairs of solutions and also created a control (water) and placed one liquid into the dialysis bag, and the other inside of the beaker which the dialysis bag sat in. In my group, I worked with Kristen and Kaliah in which we predicted that our first trial (Sucrose outside, NaCl inside) would increase in size because it would be hypertonic within the NaCl. In Procedure #3, it was somewhat similar as far as the solutions, but we had 5 different bottles of solution in which we had to decipher what the molarity is, based on the change in mass. In our first trial, we placed 3 potato cores into our bright green mystery solution and the mass went down after soaking for about 24 hours. Procedure #1 was completed on Wednesday and took the longest, we had to cut out a block of Jell-o, but it wasn’t any type of Jell-o…it was scientific Jell-o. This jello was bright pink and had the pH indicator. On Thursday, it was almost an exact replica of what we did Wednesday, but we got to cut out our own shapes and my group decided to go with a mini cube, a semi cylinder, and a triangular prism; all of these turned out to be hard to deal with. On Friday, we took a mini test on Organelles and Membranes. Overall, I really enjoyed this week because I am a very hands-on type of person, and that concludes my week in review:)
How do I write about what we did and learned in AP Biology without simply saying we did a brain teaser, took a test, did a lab, and blogged about it? Oh! I know… so here’s your weekly spiel:
Monday slowly, but surely, crept up on our weekends. Why this description? Well, there was a test on Monday that we were all ecstatic for, of course! We all came to class determined to make the best grade possible, given that we all studied our hearts out the few days (or one day) before as review. I honestly can’t remember any specific topics discussed in this test, for my mind is still stuck on the organelle quiz/test we ended up taking on the following Friday (sorry Mr. Kite), but I do know it was on Unit 2 Material. We came into class that day, ready to put our best foot (or brain cells) forward. Come Tuesday we are all excited for the three day lab we are about to explore.
Since gaining the understanding of osmosis, membrane transport, and diffusion rates- we took on the task of exploring these basic principles by working with the classics: waffle fries, cool chemicals, and jello. Sounds like a recipe for awesomeness… am I right? Our three day lab started out like a home economics class as Mr. Kite prepped our supplies. In our third procedure, we worked on setting up our experiment with potatoes that were cut or punched into little cylinders to help calculate and figure out the molarity of different solutions. Day two, we wrapped up procedure three, gathering our data and making a quick analysis: our goal was to identify the molarities of the different solutions we used by looking at the weight difference in the potato cylinders. We also had to figure out what type of osmosis or diffusion action occurred. Within day two of our lab of exploration we prepped for our next lab dealing with the jello.
Now this isn’t your normal jello, unfortunately Mr. K couldn’t get his hands on any agar… so this home made recipe would have to suffice. It looked good enough to eat! Unfortunately we are dealing with a mixture of gelatin, phenolphthalein (pH indicator), Sodium Hydroxide, with a side of Hydrochloric Acid; all of which are a severe threat if digested (and you might blow up if you mix them! Only joking… I think) None of these ingredients scream, “OHH VANILLA!” to me, so at least I wasn’t too tempted to taste some and hopefully the same for everyone else. In this procedure, we were focusing on surface area and cell size, and how each affect the rate of diffusion through a cell membrane; they are after all important factors that determine the rate of diffusion. On day three of our lab, our observations showed that not only were there different rates of diffusion, we aslo noticed that our solution we used had a high acidic content: This turned our little jello friends clear!
While we ended our week on Friday with a fun quiz on cell organelles and membranes, I came up with a few helpful tips on Do’s and Don’t during labs involving jello you can’t eat: remember the concept of “Waft, DON’T Sniff”!!!!! I unfortunately was the dummy who knew better, but my curiosity got the best of me, for I sniffed this beastly smelling jello and found myself having a head ache for the rest of the day… yea, not fun. And recap of what I learned:
- Jello can be non-edible and this one can’t be touched with bare hands,
- Sniffing jello will certainly take some brain cells ,
- Ohh and jello is cool when it jiggles!