Chicken Wing Dissection

On Thursday, Omega science classes dissected a chicken wing. As the wing was dissected, we saw Muscles, Joints,  Ligaments, Fat, Skin and Cartilage. We also learned that human arms and chicken wings are very similar. Both have the flexor and extensor muscles. I also learned that when a joint is bent, one muscle relaxes and the other contracts. Also, two bones that are connected together with muscles and cartilage are called joints.

Diffusion Lab

The lab we did this week was about indicators. In this lab, our indicator was iodine. Iodine is considered an indicator because it turns purple when it comes in contact with starch. A prediction that my group and I made, was that the iodine would enter the baggie and turn the contents of the bag purple. As we watched the bag, our theory was proved correct. We were proud that we guessed correctly, but our question was: how? We learned that the iodine was able to enter because of two terms called, Diffusion and Osmosis. Diffusion is the spread of particles through random motion. In the lab, the iodine was able to mix with the water in the beaker because of diffusion. Osmosis is the movement of water molecules through a selectively permeable membrane. In the lab, the baggie was the selectively permeable membrane. Permeable membrane is a term that means ‘all substances are able to pass through’. Selectively permeable means that only specific things are able to go in. Since iodine is almost smaller than water, it was able to enter the baggie, turning it purple. But why would we need to mix iodine with water? The answer for that is a term called ‘dilution’. Diluting means to make thinner or weaken. Both definitions were used in the lab. The iodine was thinned so it would be able to pass through the baggie more easily. It was also weakened because the school does not allow students to handle pure iodine since it is dangerous and harmful to skin and clothes. Throughout the lab, the words, concentration, hypertonic, isotonic and hypotonic constantly popped up. Concentration is a large number of things collected together in one area (molecules). With that comes 3 subcategories, hypertonic, hypotonic and isotonic. Hypertonic is high solute concentration. Hypotonic is the opposite. If you guessed, hypotonic is low solute concentration. But then where does isotonic fit in? Isotonic is equal solute concentration.

Now I will talk about what happened during the lab. While we were watching, we noticed that when the starch in the bag began to turn purple, the iodine color became slightly lighter. I believe that we were able to see how the selectively permeable membrane works. The iodine’s color became lighter because the iodine molecules were coming through the baggie (selectively permeable membrane). Through this one lab, we were able to learn many different science terms. The indicator (iodine) was clearly shown when the starch turned purple. This lab helped me understand indicators, diffusion and osmosis.

          Some connections to life that I first thought of were hot chocolate powder, salt in a soup, cows at a farm, and books in my house. Hot chocolate mix spreads out when it is put into milk or hot water. The next example was salt in a soup. When salt is put into a soup, the salt affects the whole soup, not just a section because its flavor changes and increases the soup’s flavor when we taste it. The next example, cows in a farm, is a two step way to understand diffusion and possibly the best. The first stage is when all the cows are put in a barn overnight (iodine in a bottle). Then the next day, the farmer opens the doors and all the cows go out and graze in different parts of the field (diffusion). My last example, and this is a true thing, are my books. My books start in my living room on their shelves. Then as I read them, they spread out to my basement, family room, my bedroom and bathrooms. This may not be natural diffusion but they still have gone from a starting place to other rooms. 

Class Experiment 10/11/11

Based on the lab we worked on today, there are results for me to share. Firstly, I believe that the reason the lab took so long to complete was based on how fast the iodine entered the selectively permeable baggie. Since the bag was permeable, substances were able to enter the baggie. In this case, it was the iodine. Another thing I noticed was that the starch started turning purple from the bottom. The knot was half submerged, yet the smallest corner of the bag let in the iodine first. The molecules moved from a larger concentration are to a smaller area, because it moved from a 300 milliliter bearker into a tiny baggie corner.

Please subscribe to and/or follow my blog!

Welcome!

Welcome to my blog! This blog will be updated regulary. Feel free to post your comments or questions!