Introduction
a) Background:
In this lab we used restriction enzymes. Restrictions come from bacteria and have a defense against viruses. They are like "molecular scissors" because they cut the DNA at palindromes, and this results in fragments of different lengths. Agarose Gel electrophoresis separates the DNA fragments according to their size. The slightly negatively charged DNA is drawn towards the positive pole of the gel slab. A current passes through the agarose gel, and smaller DNA fragments travel farther than the larger ones. This process is called DNA typing, DNA profiling, or DNA fingerprinting.
b) Purpose:
The purpose of this lab is to cut DNA fragments and use Gel electrophoresis to undercover the DNA profile. By comparing the DNA fragments, is is possible to trace criminals, identify certain foods, set free innocent people from jail and identify human bones. Also, you can determine the relatedness between humans and ancient peoples, test families' DNA, identify harmful organsims that cause diseases, and undergo paternity testing. There are many other uses of DNA profiling as well.
c) Process:
There is an acronym for the process: RFLP. R stands for "restriction" because the restriction enzymes are necessary to cut the DNA. F stands for "fragment" because the DNA is cut into different sized fragments. L stands for "length" because the fragments are all different lengths. P stands for "polymorphism" because the fragments all reach different locations on the gel electrophoresis. In our lab, we are going to use a pipet to transfer DNA samples to micro test tubes. Enzyme milk goes on the bottom of these tubes. We mix the components of the tubes carefully. The tubes should be incubated overnight, and after the period of incubation, the tubes are placed in a refrigerator. Loading dye is added to each tube, and then the DNA samples are placed into the electrophoresis device and agarose gel.
d) Hypothesis/Controls/Variables:
It is hard to hypothesize who the criminal is because there is no way to tell until our results from the electrophoresis are visible. The controls for this lab are the criminal's DNA. The variables are the suspects DNA. The Loading Dye is also a control. It is placed in every vile with DNA.
Discussion/Results:
It turns out that suspect 3, Chloe Krey, is the guilty person. Our gel electrophoresis results were very clear and it was easy to compare them to the actual set. We did not puncture the gel except for in the practice slot. Overall, I think that we did a great job. It helps that everyone at my table used gel electrophoresis in biology, so we already knew the proper technique.
Monday, October 25, 2010
Tuesday, October 5, 2010
Using Enzymes to Create Alternative Fuels
Introduction
a) Background:
In this lab we are attempting to create biofuels. Enzymes are key elements in this lab. Enzymes are normally proteins and they speed up the rate of chemical reactions. They are able to speed up reactions by positioning the substrate in a position so that the transition state of the reaction is stabilized. Cellulose is a common sugar used by organisms that produce cellulases, a type of enzyme. Cellulases start the transformation of cellulose into glucose. In creating biofuels, cellulases are important to change cellulose from plant walls into sugars. The sugar is then changed into ethanol through microbial fermentation. Cellulose is the main component of plant cell walls, and cellulose consists of a long chain of glucose molecules.
b) Purpose:
Research companies would complete this lab to identify the most efficient ways to create biofuels. They want to develop new fuels in a way that will not disrupt the carbon cycle and will be able to fit into systems that are already in place. This lab is helpful for our class because we will gain hands-on experience to gain an understanding of the enzymatic reaction process.
c) Process:
Day 1
We are transforming cellulose (from the plant cell wall) into cellobiose. We use an enzyme to catalyze this reaction. Microbes are able to break down cellulose. Microbes consist of bacteria, protists, and fungi. Then, an artificial substrate is created and enzymes break it down into glucose and P-Nitrophenol. At certain times, we will add a strong base to kill the enzyme and turn the P-Nitrophenol yellow. We add the strong base into small tubes, and then add the artificial substrate and cellobiase to the large tube. At certain times, we added a substance from the large beaker and put it into the small beaker. The more product that forms, the darker the yellow tint will become because the strong base adds color.
Day 2
We use a mortar and pestle to grind up a mushroom. We add extract (mushroom juice) to the reaction, and the mushroom juice carries enzymes that speed up the reaction. We will test different kinds of mushrooms and try to identify the most efficient ways to create biofuels.
d) Hypothesis/Controls/Variables:
My hypothesis is that larger mushrooms will carry stronger enzymes and will create more efficient biofuels. The controls in this lab are the cellulose and artificial substrate. The variables are the mushroom enzymes and strong base.
Discussion:
During this lab, my group put the solution in at incorrect time slots, so that was our source of error. From doing this lab I learned more about enzymes and their role in reactions. I also learned about how biofuels can be created and that in the future they will be a positive option because the fossil fuel supply could deplete.
a) Background:
In this lab we are attempting to create biofuels. Enzymes are key elements in this lab. Enzymes are normally proteins and they speed up the rate of chemical reactions. They are able to speed up reactions by positioning the substrate in a position so that the transition state of the reaction is stabilized. Cellulose is a common sugar used by organisms that produce cellulases, a type of enzyme. Cellulases start the transformation of cellulose into glucose. In creating biofuels, cellulases are important to change cellulose from plant walls into sugars. The sugar is then changed into ethanol through microbial fermentation. Cellulose is the main component of plant cell walls, and cellulose consists of a long chain of glucose molecules.
b) Purpose:
Research companies would complete this lab to identify the most efficient ways to create biofuels. They want to develop new fuels in a way that will not disrupt the carbon cycle and will be able to fit into systems that are already in place. This lab is helpful for our class because we will gain hands-on experience to gain an understanding of the enzymatic reaction process.
c) Process:
Day 1
We are transforming cellulose (from the plant cell wall) into cellobiose. We use an enzyme to catalyze this reaction. Microbes are able to break down cellulose. Microbes consist of bacteria, protists, and fungi. Then, an artificial substrate is created and enzymes break it down into glucose and P-Nitrophenol. At certain times, we will add a strong base to kill the enzyme and turn the P-Nitrophenol yellow. We add the strong base into small tubes, and then add the artificial substrate and cellobiase to the large tube. At certain times, we added a substance from the large beaker and put it into the small beaker. The more product that forms, the darker the yellow tint will become because the strong base adds color.
Day 2
We use a mortar and pestle to grind up a mushroom. We add extract (mushroom juice) to the reaction, and the mushroom juice carries enzymes that speed up the reaction. We will test different kinds of mushrooms and try to identify the most efficient ways to create biofuels.
d) Hypothesis/Controls/Variables:
My hypothesis is that larger mushrooms will carry stronger enzymes and will create more efficient biofuels. The controls in this lab are the cellulose and artificial substrate. The variables are the mushroom enzymes and strong base.
Discussion:
During this lab, my group put the solution in at incorrect time slots, so that was our source of error. From doing this lab I learned more about enzymes and their role in reactions. I also learned about how biofuels can be created and that in the future they will be a positive option because the fossil fuel supply could deplete.
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