Unit 2 Reflection

In this unit we focused on the 4 macromolecules. The 4 macromolecules are carbohydrates, lipids, proteins, and nucleic acid. Carbohydrates are sugars that are made with rings of carbon, hydrogen, and oxygen. They are a main source of energy, and come as mono, di, and polysaccharides. Lipids are long chains of carbon and hydrogen, called fatty acids. Lipids are used to store energy, make up cell walls, and produce hormones. There are 2 types of lipids, saturated, which is not healthy for you, and unsaturated which is better for your health. Next we have proteins, which are made up of smaller molecules called amino acids. Proteins support the body, speed up chemical reactions, help cells communicate, and let things through the cell membrane. Lastly, we learned about nucleic acids, which are composed of thousands of repeating nucleotides. Nucleotides are made of phisphate, sugar, and nitrogen. We can see nucleic acids in DNA and RNA.  

In addition to the four macromolecules, we learned about ATP and enzymes. ATP is a nucleic acid that is the primary energy transferring molecule in the cell, and enzymes are parts of proteins that speed up chemical reactions. The substrate (molecule enzyme works on) attaches itself to the enzyme on the active site (where the substrate and enzyme are attached. The enzyme then speeds up the reaction and creates the product at a faster rate. Enzymes are important because they can make more product in less time, and lower the amount of energy needed to make a reaction occur. 


After learning about these concepts, we did some labs to demonstrate them. The first lab we did was the sweetness lab, where we tasted different sugars to see the difference between the taste of mono, di, and polysaccharides. We found that monosaccharides were generally the sweetest and poly generally the most bland. We also did the cheese lab where we curdled milk to see which conditions are better to curdle milk, and what curdling agent. We learned that the enzyme chymosin in acidic and hot conditions was the best to curdle milk.  
All in all, Unit 2 was very informative and taught us a lot in detail about the four macromolecules. The labs were fun, especially the cheese lab because it was very hands on and gave us a good demonstration, opposed to just learning from the textbook. Unit 2 was very fun to learn about, and I hope we can go in more depth over the course of the year. 

Sweetness Lab

1. Initially, we believed that the the fructose, sucrose, glucose, and lactose would taste sweet and that the galactose, maltose, starch, and cellulose would not. However, once we completed our experiment, we found that the monosaccharides - fructose, maltose, glucose, and galactose - were the sweetest with the exception of galactose which was rather bland. The disaccharides  - maltose, and lactose - compared to the monosaccharides were generally less sweet with the exception of sucrose which was very sweet.  The polysaccharides - starch and cellulose- were very bland and did not have any sweetness.

2. The structure of carbohydrates may affect how they are used by cells and organisms. Carbohydrates are large molecules that provide and store energy. This means that the polysaccharides (which have 3 rings) would provide the most amount of energy for cells, and organisms, and would be a long term source of energy. Monosaccharides (which have one ring), would be a temporary source of energy for organisms, and Disaccharides (which have 2 rings) would provide a little bit more energy than a monosaccharide could provide.

3. Not everyone in my group had the same rating of sweetness that I did. This may be because of the number of taste buds in our mouths vary, making us taste different levels of sweetness. Another reason our data could be different is because there may have been lingering flavors of food still in our mouths, changing the level of sweetness that we tasted.

4. According to kids health.org, " Taste buds are sensory organs that are found on your tongue and allow you to experience tastes....The average person has about 10,000 taste buds and they're replaced every 2 weeks or so...Olfactory receptors inside the uppermost part of the nose contain special cells that help you smell. They send messages to the brain." After reading this, I can see that my group may have tasted different levels of sweetness because they might have had a cold, clogging their nose which obstructed their ability to taste. They may have also had a lingering flavor still on their last bud which obstructed them from tasting the sugars properly. 

What is Biology?

Jean Lab

Conclusion:

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 the 25% concentration was the best to fade color without that much visible damage. The reason we picked 25% is because 100% and and 50% had extensive damage, and while 12.5% and 0% didn't suffer as much damage, they did not change the color either. The 25% concentration of bleach ranked a 4 in both color removal and fabric damage. Bleach is known to break down pigments, and this concentration broke the pigments down enough without causing excessive damage.

However, there could have been errors in this experiment, as the jean material were not always in the bleach solution for exactly 1 minute. There was no timer while doing this experiment, so the timing may not have been exact. Due to this error, I would recommend that when doing this lab in the future, we use a timer so that our data can be more accurate.

This lab was done to demonstrate and set an example of how future labs should be. It taught us how to do the different steps, and also taught us about how bleach affects jean material and how it breaks down the pigment. Based on my experience from this lab, I understood how to properly execute an experiment  and how to perform a lab correctly.