Unit 2 Reflection

      In this unit we learned about biological units on the smaller scale and how they interact with each other. First, we learned about properties of atoms and molecules, including adhesion to other substances, cohesion to itself, and how polar molecules attract to each other. We then learned about the 4 main large molecules (macromolecules) which are carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates are the main source of energy for consumers, lipids store energy, proteins serve many different functions such as cell walls and enzymes for chemical , and nucleic acids serve as sources of information.

   

     This unit was interesting, and overall I think it went very well. I was able to understand the information presented with little difficulty or confusion. I learned that reviewing over the notes right after watching the vodcasts helped me retain the material even better. Throughout this unit, I learned a lot about how the topics taught are relevant to our daily life, for example, how the carbohydrate, fructose, is present in a large amount of the foods we eat everyday.

     Some of the information I learned was enforced through the sweetness lab and the cheese lab. In the sweetness lab, I learned how the different ringed structures of carbohydrates can effect the sweetness of a sugar. I found out that the monosaccharides, or the carbohydrates with one ring, are sweeter than the polysaccharides, or the multi-ringed carbohydrates. In the cheese lab I saw a real life example of how enzymes can be affected. The enzymes of rennin and chymosin worked different different paces under different temperatures and pH's, which showed how an enzyme can be denatured. The enzyme virtual lab was also a fun way of demonstrating how a drastic change in pH and temperature can decrease the amount of product created by an enzyme.

     A topic that I want to learned more about is DNA and RNA. I would like to learn more about the difference and their different functions. I am also curious as to how the string of DNA is translated into characteristics like eye color and height.

Sweetness Lab

     This lab was done to find the relationship of a carbohydrates structure to its sweetness. According to results from the experiment, monosaccharides are the sweetest, and polysaccharides are not sweet, however, they are bland or slightly bitter. In our experiment, we found that fructose was the sweetest along with sucrose and glucose, and according to the information collected in step 2, these are all monosaccharides. In addition, cellulose and starch were the most bitter and least sweet, and according to the information collected, they are polysaccharides. Galactose, maltose, and lactose, which are disaccharides, were all towards the middle of the sweetness scale, which further supports the claim that monosaccharides are sweet and polysaccharides aren't, as disaccharides are in the middle.

     A carbohydrate's structure may affect how it interacts with other molecules in the body such as lipids and nucleic acids. The monosaccharides, which are the smaller carbohydrates, may interact on the smaller scale, such as with cells, and serve smaller functions. The larger polysaccharides, may serve larger functions, like storing energy.

    The testers within my group did not give all the samples the same ratings. This could possibly due to a difference in the way our taste buds work. If someone is used to tasting really sweet things, then they may not thing a sample is very sweet, while someone else could think its very sweet. Also, if one person tasted the sample for longer than another, they may have a different experience tasting the sample.

     According to PubMed Health the tongue contains many taste buds and taste papillae, which help perceive the dominant tastes of sweet, sour, bitter, and salty. The article states that on average, adults have about 2,000 to 4,000 taste buds. Our perception of the sweetness of the different sugars could have been due to a different amount of taste buds on our tongues. The 4 dominant tastes have can be tasted most strongly on different areas of the tongue. The location where we tasted the sample on our tongue could have also affected the way we tasted the sugar.

What is Biology?

Jean Lab

     In this lab we asked the question, what concentration of bleach is best to fade the color out of new denim material in 10 minutes without visible damage to the fabric? We found that that a higher concentration of bleach leads to more color fading without visible fabric damage. The average color removal of 100% concentration bleach was 6.3, while the 12.5% concentration had and average of 1. The color of the 100% concentration was also far lighter than the control and the 12.5% concentration. According to UCSB Science Line , bleach, oxidizes pigment, making it reflect all colors of light, meaning it emits white light. This supports our claim, because if pigment is oxidized by bleach, then a higher concentration should make a pigment appear lighter.

     While our hypothesis was supported by our data, there could have been errors due to the fact that we bleached one of the 100% jean square and one 50% jean squares by themselves, instead of 3 at a time. This could have affected our results, since they were in the bleach by themselves, the bleach could have absorbed more of the pigment. This shows in out results because one of the 100% squares was slightly lighter than the rest. Also, we had many different timers going on at the same time, so some of our timing may have been off, resulting in some squares being in the bleach longer than others. Due these errors, in future experiments I would recommend making sure directions are written thoroughly, and to read instructions with an eye for detail, so there are no misunderstandings when executing the experiment. In the future, it would also be helpful to have a method for timing how long the squares have been in the bleach that would help avoid confusion and disorganization.

     This lab was done to demonstrate our understanding of the scientific method. Although, the lab wasn't related to biology, it allowed us to use the different steps of the scientific method. During this lab, I practiced identifying controls, constants, and independent and dependent variables in and experiment, which was discussed in the scientific method vodcasts. I also applied the concept of the metric system, which was also talked about in a vodcast when I measured out the bleach and water in milliliters. Based on my experience from this lab, this experiment can have a variety of practical, real world applications. For example, if I ever had a stain in something white/light, like clothing or carpet, I could use bleach to fade the stain, just like it faded the pigment in the jeans.