2. If the signal channel were stuck in the open position, the cell would keep sending a strong signal to the brain. However, the cell would quickly reach a point where its chemical-electrical gradient is no longer proper for other cellular functions. If the channel were stuck the closed position, no signal would reach the brain.
3. The channel is the leak, the pump is the bucket, and the inside of the cell represents the boat.
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Optical Illusions:
The checker shadow illusion was very convincing, although I had already seen the illusion before and was aware that the squares marked A and B were in fact the same. Still, cutting out the individual squares to prove this fact was a valuable exercise. As I worked through more optical illusions it became clear to me that it is actually fairly simple to dupe the brain into perceiving things incorrectly. I was struck by how the brain, rather than simply interpreting things as they actually are, interprets images in relation to one another, and then attempts an explanation. Furthermore, despite knowing the 'trick' of the illusion, I still found myself unable to perceive the image properly. One partial exception to this is the checker shadow illusion, where I found the focusing solely on square B allowed me to see it as a darker square, which was nearly identical to square A.
The curve ball illusion was my favorite, in part because it had a fairly simple explanation (switching from central vision to peripheral vision) and in part because of its applicability (the curve ball and even fast ball in baseball). I'm curious how often tricks like this manifest themselves in every day life - for example, how do we interpret information from our peripheral vision while driving, and how close to correct is it? I'm also curious about how people with only peripheral vision (I know an adult that lost his central vision) perceive illusions.
Other illusions were able to use all sorts of tricks - by altering color, depth perception, and curves, many illusions could be created. One of the most intriguing illusions was the spinning cat illusion, in which a cat, in theory, could be perceived as spinning either clockwise or counterclockwise. I was only able to see counterclockwise, aside from about half a second where it suddenly reversed and then switched back again. Despite staring at the cat for several minutes, I never was able to control the spin. My lab partner (Melissa) was able to see it change directions. I found it intriguing haw different people perceive things.
I was intrigued by the examples of color blindness. Although I have seen the dot tests before, I had not seen such a collection of pictures for various forms of color blindness. This greatly enhanced by understanding of the significance of color blindness, and made me very thankful for the fact that I am not color blind.
FOOD/FLUORESCENCE
During lab time we extracted coloring from cabbage and spinach, and placed the colors in solutions with a pH ranging from 1 to 11. The cabbage extract ranged from dark pink at pH 1, though light pink, purple, blue, teal, and light green at pH 11. The color range was less significant for the spinach extract, which was an orange-ish brown color at pH 1, a light yellow-green color at pHs of 3 and 5, green through pH 9, and a dark, bright green at pH 10 and 11.
Bleach and hydrogen peroxide both neutralized color, although the bleach acted more quickly and more strongly. This effect is due to the oxidation process, as both agents oxidize the conjugated double bonds that are largely responsible for causing light to reflect in the visible spectrum.
We also observed several objects and solutions under a black light. Fluorescent proteins fluoresce brightly at their particular color, quinine in tonic water fluoresces a bright blue, as does a white towel. Chlorophyll fluoresces a very dark red color.
The color white can reflect light very efficiently in a manner that does not overwhelm us. In other words, the color white redirects light energy as opposed to acting like a mirror and shining it right back in our faces.
Rods perceive blue-green light most easily.
The double bonds in many colored fruits and vegetables serve as an outlet for oxidizing agents in the body. An omnipresence of these chemicals will reduce the oxidizing reactions that might otherwise occur with DNA.
-COOH can hydrogen bond with H2O, increasing solubility. Raising the alkalinity will cause the base to abstract a hydrogen from the –COOH, leaving a negative charge on the pectin. Two pectin molecules at a time can therefore form a favorable interaction with the Calcium ion.
All of the -COOH and -OH groups allow pectin to easily Hyrdogen bond with water.
RCOOH +NaHCO3 à RCOONa + H2O(l) +CO2(g)
The product will be less soluble, as the RCOONa will be less able to Hydrogen bond. The result is that the pectin will be less soluble, and will not become as mushy during cooking time.
All salts are not created the same. As the paper points out, there is a difference in salt based upon how fine the crystals are. Furthermore, there are various other salts used in cooking (such as sodium nitrite) that have different properties. That being said, the various salts in the slideshow seemed nearly identical. Although some contain traces of elements such as Magnesium and Calcium, overall there was little difference in the salts, and the properties of the salts should be very similar.
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