Chicken wing anatomy lab- 10/20/11

Today, we dissected a chicken wing. The purpose of this lab was to see the different types of tissues and organs and to compare them to our body (arm). The skin of the chicken wing was a little bumpy. It was peach white and it's an epithelial tissue. The tissue connects to the muscle tissue. Next, fat is a type of a connective tissue. The fat of a chicken wing is white. The fat connects to the muscle. The muscle has a smooth surface. It is a light pink color, almost pale, and of course, it is a muscle tissue. In addition, it connects to a bone/ligament. A ligament is a connective tissue, and is white. Ligaments connect bones to other bones at joints. In between bones there is cartilage. This is a white, slippery materials that connect joints. Lastly, there is the nerve. The nerve looks like a big piece of thread and is a very dark color. It connects to muscle. These are all the parts that helps the chicken wing work. Chicken wings are similar to human arms because their muscles have to relax and contract to work like humans. But, they're also different than humans since our arms are way bigger in proportion.

DIffusion lab paragraphs/essay 10/14/11

Neha Puttagunta                                                                                             10/14/11

Green                                                                                                     Mrs.Rousseau

                                                     Diffusion lab

            The purpose of this lab was to help understand how the cell membrane works. Basically, what kind of substances it lets in and what it doesn’t let in. A prediction made in this lab was that the iodine would affect the cornstarch. In the lab, the molecules had to move from one place to another. This is called diffusion. Diffusion has to do with the cell membrane also. Diffusion is the process by which molecules move from an area of higher concentration to an area of lower concentration. Diffusion can happen anywhere, but it also happens in the cell membrane. When this occurs, it’s called osmosis. Osmosis requires water, because it’s the diffusion of water molecules through a selectively permeable membrane. The cell membrane lets in certain substances and the molecules move to get more space from the cell. In this lab, the iodine was an indicator, because when it came in contact with the cornstarch, it turned the cornstarch purple. Concentration is the amount of molecules in proportion to the volume. The molecules in the iodine needed to move from the beaker (the higher concentration) to the baggie and the cornstarch (the lower concentration) because they needed to move around. Therefore, the iodine turned the cornstarch a different color. Dilution is to lessen concentration, by adding water or solvent in a substance. Lower concentration and higher concentration have other names. Hypotonic would be the area of lower concentration and hypertonic is higher or more concentration. If there is equal concentration, that would be considered isotonic. Molecules try and rearrange themselves to become isotonic.

The lab was very similar to an actual cell membrane. The cornstarch combined with water was placed in the iodine that was in the beaker. After 15 minutes, the cornstarch in the baggie was tinted purple. This is an example of diffusion. The baggie was semi-permeable to the iodine, which means it allowed the molecules of only the iodine to enter into the baggie. The affect of that turned the cornstarch that was in the baggie purple. The molecules in the substance needed place to move and as soon as they got the chance, they moved into the baggie. They needed to move to get space. The iodine was an indicator to the cornstarch. The cornstarch also wanted to diffuse, but it couldn’t because the molecules were too big to go through the barrier, and that’s why the cell membrane wasn’t letting them through. The more time the cornstarch is left in the baggie, the more the molecules move into the baggie, therefore, it has more of an impact on the color. This is like the cell membrane, because the membrane lets certain things in that are small enough to go through the barrier, and let’s out waste products just the like the baggie. It controls what enters in and out of the cell.

Diffusion doesn’t only have to do with cells. It can happen in our lives as well. For example, air freshener in a room. The molecules from the air freshener diffuse to get more room, therefore spreading throughout the entire room, causing it to smell. Another example is garbage. The rotten food inside can definitely be smelled from a distance. That is diffusion. One more example is a drop of ink in water. What does it do? It spreads, diffuses. Drinking tea is the last example. If a teabag is used, then it is diffusion because the tea powder diffuses into the water to give it its flavor. These are all examples of diffusion. Remember: diffusion happens everywhere, even in the human body’s very own cells!

Omega science diffusion lab: 10/11/11

Today we did a lab based on the cell membrane. One thing I learned from this lab is how diffusion and osmosis works. Also, I know that idodine is known as an "indicator" because when it's combined with starches, it turns a shade of purple. Molecules tend to move from areas of high conecntration to areas of low concentration, because they need their own space and spread out once they get their space. The plastic bag from the experiment acts like the cell membrane, letting in certain substances that fit in and not letting in other substances that don't.