Chicken Wing Anatomy Lab - 10/20/11

      In class today, we dissected a chicken wing. The purpose of this lab was to show us the similarities and differences in chicken muscles and human muscles, and also to show us how the muscles work. I learned that we have muscles called the flexor and extensor. While one of these muscles relaxes, the other one contracts, helping the wing or arm move. The first thing we did was cut through the peachy white skin of the chicken wing, which is an epithelial tissue. Next, we got to the white fat, a connective tissue. Other examples of connective tissues are ligaments and cartilage. After that, we struck the muscle, which was baby pink and obviously muscle tissue. That was where we found the flexor and extensor. If you go even deeper, there is bones. Also, a nerve is like a long piece of thread and it is usually a dark color. The similarities between our muscles and the chickens' is that the work the same way. The difference is that our arms are greater in proportion to chicken wings. That is how the muscles are the same and different, as well as the parts of a chicken wing.

Diffusion Lab - 10/13/11 - Paragraphs

Diffusion Lab

            This experiment was to symbolize the cell membrane, and the nutrients cells need to stay healthy. The prediction that was most common was that the iodine would somehow come in contact with the starch. The baggie acts as a cell membrane/barrier that only leaves gaps big enough for the iodine to squeeze through. This is the same concept as cells.  The cell has a cell membrane, that is permeable, so that the nutrients and proteins can go through, but the organelles of the cells don’t go out. Concentration is the amount of molecules in proportion to the volume. This movement of molecules is called diffusion. Osmosis is this exact same movement, except osmosis only happens with water molecules. An indicator, such as the iodine, means that when it comes in contact with the starch, the solution turns purple. Diluting a substance means to lower the concentration of it. There are three terms that go along with concentration: hypertonic, hypotonic, and isotonic. Hypertonic means more concentration, hypotonic means less concentration and isotonic means equal concentration.

            After placing the cornstarch–filled baggie in the iodine solution, it was left to sit there for a few minutes. When the baggie was taken out, the indicator (iodine) had left strips of purple in the cornstarch. Given more time, it would have turned all the contents of the bag purple. The main question with this result was: How did the iodine get into the bag? It’s quite possible. The bag acts as a selectively permeable membrane, which means that it is picky in what the membrane lets in. Since the iodine molecules were small enough to enter the bag, they were let in. They went in because they were diffusing, moving from an area of higher concentration to an area of lower concentration. On the other hand, even though the cornstarch wanted to diffuse, it couldn’t because the molecules were too big to pass through the barrier. This experiment was a replica of the cell system in human bodies, the iodine being the nutrients and energy the cell needs, and the baggie being the cell itself. By having this access to the cell, the nutrients can easily supply the cells, and the waste product can leave the cell, without any organelles sneaking out.

            There are many connections that can be made to real life. First, an example of diffusion: when the stove in a kitchen is turned on, the gas used to fuel the fire diffuses into the air so it can be smelled. Another example of diffusion is a nail polish bottle. If it’s opened, the molecules diffuse and, again, it can be smelled from a distance. The third example of diffusion is when a fire is lit, you can easily smell the smoke from it, which means the molecules are diffusing. Last, but not least, if a cologne bottle is opened, the smell is overpowering, which is how you can tell it is diffusing!

Omega Science Lab: October 11, 2011 (Diffusion)

Today, in the Omega Science Lab, we did an experiment with iodine and cornstarch. It was a replica of our cells and nutrients, the baggie being the cell and the iodine being the nutrients the cell needs to stay healthy. I learned that iodine is an indicator, which means that when it comes in contact with a starch, it turns purple. When we put the baggie in the iodine solution, it didn't turn purple right away, it took a few minutes. We also learned that by mixing the iodine with water, we were diluting it. Diffusion is when molecules spread out, they also tend to move from higher concentrated areas to lower concentrated areas, just like we would spread into the hall if we were squished in a room. By the time we took our bags out from the solution, the turned from white to white with vibrant streaks of purple. We compared this to our cells, since the baggie is the cell membrane, it controls what goes into the cell, and the iodine ( the nutrients our cells need to function) can penetrate that and, if they are small enough, get through the barrier.