Unit 3 Reflection

This unit contained information explaining the cell theory, which is the belief that all things are composed of cells, cells are the basic unit of life, and new cells are generated from existing cells. I also learned that prokaryotic cells have no nucleus, 1 chromosome, and circular DNA called plasmids. Eukaryotic cells have nucleus and long chains of DNA called chromosomes. 
I also learned that each macromolecule makes up a different part of the cell, serving a different purpose. For example: Carbohydrates make up call walls, help cells communicate , and they store energy. Proteins are catalytic building blocks that allow molecules in and out of the cell. Lipids make up plasma, and nucleotides hold information.
The Unit then explains osmosis which is the diffusion of water across a selectively permeable membrane. Tonic is the ability of a surrounding solution to cause a cell to gain or lose water. Cells change in response to different environmental conditions because of the typically small molecules- Turgor pressure exists inside the cell when the cell swell.
Photosynthesis is the process in which plants produce glucose and oxygen using sunlight and carbon dioxide. Plants grow best under red and blue light, and worst under green and yellow light.
Cellular respiration of process of cells breaking down glucose and energy. Both of these processes rely on each other.
An essential theme was understanding exactly what part of the cell performs what function. The understanding of parts of the cell is essential in this unit to completely understand photosynthesis and cellular respiration. This topic was thoroughly explained.

One of my weaknesses was keeping track of which process produced what product(s). I eventually figured out that glycolysis is the process in which one molecule of glucose is broken in half, producing two molecules of pyruvic acid, a 3-carbon compound. The Krebs cycle breaks down pyruvic acid into carbon dioxide in a series of energy-extracting reactions. I want to learn more about the Krebs cycle.

Egg Diffusion Lab

In this lab we asked the question, "How and why does a cell's internal environment change, as it's external environment changes?" We tested how hypertonic and hypotonic solutions affect a raw egg. First, we soaked an egg in vinegar. Next, in the hypotonic solution, the egg grew in size. This happened because the water entered the egg, increasing its size.Then we soaked the egg in the hypertonic solution, fructose corn syrup, the egg shriveled and decreased in size. The egg got smaller because the water exited out of the membrane, causing the shrinkage.

Placing the egg in vinegar did not change the shape or size of the egg, it did however change it's texture and changed it into a balloon-like substance. The water increased the size of the egg, because the water went into it. When soaked in sugar, the egg shrank and shriveled into a deformed egg, which appeared to have dents in the surface.

The mass of the egg changed -47.15% when soaked in the sugar concentration. The circumference decreased -24.24%. The solvent of sugar created indentations into the egg.

The internal environment of the egg changed when it was soaked in vinegar. Vinegar in the external environment caused the egg to become almost balloon-like. Water caused the egg to increase in size, and sugar water caused the egg's size to decrease.

This lab demonstrates the principle that hypertonic, isotonic, and hypotonic solutions cause a solute to change from its original state.

I think that foods such as pickles are kept in a jar with vinegar in order to preserve them. This concept applies to many different foods and how they are preserved.

Based on this experiment, I would like to test the affects of vinegar on other foods.

Egg Cell Macromolecules Lab

In this lab we asked the question "Can macromolecules be identified in an egg cell?" We found that the egg membrane tested positive for protein. The egg membrane turned from blue to purple, signifying that the macromolecule was present. The quantitative amount of protein the egg membrane contained was at a level of 7. The egg membrane is naturally white, so we knew that the macromolecule, protein, was in it when the membrane turned purple. The egg membrane tested positive for having monosaccharides because the carbohydrates store energy there. This concept connects to the information learned in the Unit 4 Miniature Biology Vodcast. This data supports our claim because carbohydrates are sugars broken down by mitochondria to make ATP.

Our data contradicts the expected results because not enough drops of Sudan III were placed into the test tubes to accurately test for lipids. This affected the results because the lack of Sudan III caused the egg membrane to test negative for the lipids. An error that could have occurred would be not timing how long the test tubes sat in hot water for the monosaccharide test. This would affect results because the benedict's solution would not have enough time to change from its blue color. Due to these errors,  in future experiments I would recommend telling the students repetitively the number of drops needed in each of the tests.

This lab was done to demonstrate the different macromolecules that can be found in specific parts of a cell. From this lab I learned that an egg membrane contains, monosaccharides, polysaccharides, and protein. The egg yolk contains lipids, and the egg white is protein. This helps me understand the concept of macromolecules and their functions, such as how monosaccharides and polysaccharides are used as energy storage. Based on my experience from this lab, I can apply this information to our recent vodcast, "What does a Cell do?", and  connect the information about where macromolecules are located.