Unit 2 Reflection

This unit was about molecules. One of our first themes was matter, in which we learned about atoms, the basic unit of matter; elements, pure substances made of a single type of atom; compounds and molecules, which are formed by more than one element; and ionic, covalent, and hydrogen bonds. Another theme was water, which is polar, very attractive, and a good solvent. Also, we learned about acids, which are less than 7 on the pH scale, and bases, which are greater than 7 on the pH scale.

We also learned about macromolecules such as carbohydrates, lipids, proteins, and nucleic acids. Carbohydrates are rings of carbon, hydrogen, and oxygen, and can be monosaccharides (one-ringed), disaccharides (two-ringed), or polysaccharides (many rings). They are used as a main source of energy. Lipids are long chains of fatty acids, which can be saturated or unsaturated, and are mostly nonpolar. Some lipids, such as phospholipids, have a hydrophilic head and hydrophobic fatty acid tail. Lipids store energy, make up cell membranes, and make hormones. Proteins are made of amino acids, and can be structural proteins, which support the body, or enzymes, which speed up chemical reactions by lowering their activation energy. Nucleic acids are made of nucleotides, which are made of a sugar, phosphate group, and a nitrogen base. Nucleotides bond together in one strand to make RNA, or in two strands to make DNA, a blueprint for making proteins. ATP, another nucleic acid, is an energy transferring molecule.

We also learned that proteins (and enzymes, since enzymes are proteins), have four levels of structure and an optimal environment, which includes temperature and pH. If an enzyme is kept in an unoptimal environment for a long time, it may become denatured.

We did many labs during this unit. From these labs, I learned more about the information covered in the vodcast. For example, in our sugar lab, I learned that monosaccharides are often sweeter than disaccharides and polysaccharides. In our cheese lab, I learned that curdling agents, which are an enzyme, have an optimal environment of acidic and hot.

While many of our labs were successes and incredibly productive, the cheese lab was a setback because our data was not accurate, and did not support our claim because we made some errors during the experiment. A topic that was confusing at first was protein structure. At first, I did not understand the differences between primary and secondary structure, but now I understand that primary is the bonds between amino acids that keep them in a chain, and secondary is the bonds between amino acids that aren't necessary next to each other.



From these experiences, I learned about matter, types of bonds, properties of water, the functions and structures of different macromolecules, and enzyme structure. I also learned proper experiment procedure, and how to better follow instructions, which makes me a better student now.

I would like to learn more about different types of proteins. Since there are a limited number of amino acids, there must also be a limited number of proteins. How do the amino acids in a protein affect the protein's function? Do all proteins that have the same structure have the same function? Is the type of protein determined by the primary structure of the protein, or by all four structure?