Carbohydrate Sweetness Lab Analysis

In this lab we asked whether there is a difference in taste with monosaccharides, disaccharides, and polysaccharides. Our hypothesis that Galactose, a monosaccharide, would taste sweet was supported by our evidence. Sucrose, Glucose, Fructose, Galactose, and Maltose all tasted sweet. This is because they are all either monosaccharides or disaccharides, which taste sweeter than polysaccharides. Specifically Galactose is a monosaccharide.

While our hypothesis was supported by our data, there could have been possible errors due to rushed and unequal sampling, the lack of both a positive and negative control, and different perceptions of sweetness. While tasting some of the last samples we tried, Lactose, Starch, and Cellulose, we were hurrying to finish with the rest of the class. This and taking different sized samples could have resulted in some larger samples tasting sweeter than smaller samples, and poor observations for the later carbohydrates we tried. While we had a control, it wasn't positive or negative, it was a rating of 100 to base the other samples off of. This means that we didn't know how sweet something that would be rated 200 would taste, or something rated 0. Different perceptions of sweetness may have also affected our data. People can perceive sweetness differently due to several factors such as age, type of food previously eaten, how hungry you are, if you smoke, if you are obese, if you are pregnant, sickness or disease, and temperature of food. Several of these factors don't apply to this situation, such as age, which isn't a factor until around 45, smoking, because neither of us smoke, pregnancy, because we are both males,  sickness, because neither of us were sick, and temperature of food, because the food was the same temperature for both of us. But having just finished lunch, hunger and food previously eaten may have been a factor in affecting out sense of taste. .In future experiments, I recommend moving at a faster pace throughout the entire lab, but not rushing to finish, and also adding a positive and negative control to more accurately rate samples. Unfortunately, nothing can be done about eating before doing this because the class is always after lunch.

This lab was done to demonstrate how monosaccharides, disaccharides, and polysaccharides, while all made of the same elements, have different flavors. From this lab I learned that all carbohydrates have different properties, which helps me understand how they are used differently in plants, animals, and food production. Based on my experience from this lab, I will better understand what is in my food and how healthy it is, for example, fructose tastes very sweet and is also unhealthy.

Carbohydrate	Type of Carbohydrate	Degree of Sweetness (0 to 200)
Sucrose	Disaccharide	100
Glucose	Monosaccharide	120
Fructose	Monosaccharide	150
Galactose	Monosaccharide	70
Maltose	Disaccharide	60
Lactose	Disaccharide	20
Starch	Polysaccharide	0
Cellulose	Polysaccharide	0

Galactose, pictured in the center, is a monosaccharide.

Biology Collage

Jean Lab Conclusion

Jean Lab Conclusion

In this lab we investigated what concentration of bleach would best fade denim jeans with minimum damage to the fabric. We found that 25% bleach was the best concentration. Denim jean samples tested with the 100% solution were completely faded to a yellow color, and were thinner than the other samples. The 50% solution caused the jeans to fade to lesser yellow, but still damaged. The 25% solution didn’t fade the jeans that much, but there was no yellowing or noticeable damage. The 12.5% solution didn’t produce any noticeable difference to the fabric. The 0% solution was our control for comparison. Bleach is a well known substance used for removing color from fabrics. It is also an acid, and will damage fabrics. Therefore, the higher concentrations of bleach faded the fabric, but also caused damage to them, so an amount high enough to fade, but low enough to not damage the fabric was needed.

While our hypothesis was supported by our data, there could have been errors due to measurement errors caused by spills while pouring liquids, and also some pieces of denim had slightly more bleach exposure than others. These errors may have caused some denim samples to have faded more or less than they would have if they were all exposed for the exact same amount of time. In future experiments, we could be more careful with measuring and pouring liquids, and have more people add and remove the samples from any solutions to ensure that they have all had equal treatment.

This lab was done to demonstrate the steps of the scientific method and how to properly run an experiment. From this lab I learned how to make an experiment successful, and how I can make sure future experiments are mostly free of mistakes, which helps me understand the concepts of controls, variables, and hypotheses. Based on my experience from this lab, I will be able to use the scientific method to answer other scientific questions.

Concentration of Bleach	Average Fading (1 to 10)
0%	0
12.5%	1
25%	4
50%	6.6
100%	9.3
Concentration of Bleach	Average Damage of Fabric (1 to 10)
0%	0
12.5%	0
25%	1
50%	3
100%	5.5