Introduction:
Every person in the world has their own unique DNA fingerprint DNA fingerprinting can help to identify and compare individuals. Much of every individuals DNA is the exact same. This makes it difficult to distiguish different people. Microsatellites are used to make this identification easier. Microsatellites are short pieces of DNA that repeat many times in one's DNA sequence. Any biological material can be used for DNA fingerprinting such as, body tissues, body fluids, and hair. Even some dired material such as blood stains can be used. To create this DNA fingerprint from the DNA restriction enzymes must be used.
Restriction enzymes act like small DNA scissors. These enzymes recognizes specific base pairs that tell it to cut the DNA at that point. The spots in which the enzymes make the cuts are called restriction sites. This can result in many different pieces or fragments along one DNA strand. Once the DNA has been cut it can be seperated by the size of the fragments. This seperation is created by using a process called Agarose gel electrophoresis. This process consists of inserting the DNA into an agrose gel slab and passing an electircal current through it. The DNA fragment (which are negatively charged) are attracted to the postively charged end. This is the point in the process that creates the seperation. The bigger DNA fragments are unable to pass through the gel as easily as the small fragments consequently causing them to not travel as far. All of the fragments that are the same size come togethor to form bands. Once the gel is stained we can see these bands. This final result of the way that they line up is the DNA fingerprint.
Results/Observation:
Lane 4 or sample number 3 ended up matching the the crime scene DNA from lane 1. All of the other lanes had differing results with the strips being at different places along the gel. The crime scene matched perfectly to sample 3 which happened to be the sample from Katie Records.
Discussion:
The gel ended up working correctly and the restriction enzyme obviously did its job as the molecular scissors. The smaller pieces moved farther along the gel as expected compared to the larger fragments that didn't make it as far. Some possible sources of error could have been the loading dye not weighing down the sample and the DNA floating out and mixing with the other DNA. Another source of error could have occurred when undergoing the difficult task of inserting the samples into the small slots in the gel. Although some incidents did occur, we were able to work past these and receive the correct results.
Sources:
McGuigan, Brendan. "What Is DNA Fingerprinting?." wiseGeek. wiseGeek, 08/9/2010. Web. 25 Oct 2010. <http://www.wisegeek.com/what-is-dna-fingerprinting.htm>.
Monday, October 25, 2010
Tuesday, October 5, 2010
Petroleum No More
Introduction/Procedure
Enzymes which are generally proteins, speed up the rate of chemical reactions. They have specific three dimensional structures and reduce the energy needed to carry out a chemical reaction (otherwise known as the activation energy). Since the enzymes reduce the amount of activation energy the reaction occurs at a quicker pace. Enzymes do not chemically react with the substrate so they can continually help to convert reactants to products. Changes in pH and salinity negatively affect the enzymes productivity. Another factor in the speed of the reaction is heat. More heat, therefor faster moving enzyme and substrate molecules, causes more collisions and speeds up the reaction. Most enzymes function best at medium temperatures however there are of course exceptions. The enzymes "natural habitat" is a good reflection of what are optimal temperatures for the enzymes to operate under. Another component to the speed of reaction is concentration of molecules. Until the point of excess, enzymes will speed up the reaction if there are more molecules. This knowledge of enzymes will help us in our lab because we are using cellobiase, (an enzyme) to break down cellobiose to glucose. Also our knowledge of how pH, temperature, and concentration affect reactions will come into consideration when we analyze how these affect our break down of cellobiose. This ability to break down celluloses into glucose is used by biofuel industrys in search of an alternative to petroleum. The glucose can be converted to ethonol which can be used to power engines. In our lab we are not trying to solve the worlds pollution problems, merely trying to understand the process. We are going to use cellubiase to break down cellubiose into glucose. During the process we will take part of the solution at different times in the reaction and attempt to use a stop solution to take "snap shots" of the process. Using p-nitro to turn the glucose a color visible to human eyes, we will be able to see glucose in the making. I predict this will be a successful lab but precision will be necessary throughout.
Results/Observations
During the experiment every later interval progressively became a stronger yellow color. In the beginning the yellow was hard to see and closer to a clear color. Towards the end the last tube that we transfered it into turned a very strong yellow color. This was also true when we replaced the enzyme with mushroom extract. The results seemed to be nearly identical to the previous days tubes.
Discussion:
This means that the experiment did end up working. The cellobiose inside the main tube was being broken down into glucose and the results were obvious. It also proved that the mushroom acted just like cellobiase in that it also produced the glucose. Although our lab ended up working errors could have occurred during the process such as maybe a certain mushroom doesn't act like cellobiase. If it didn't break down the cellobiose then the p-nitro would have no glucose to turn yellow and we would have to results to look at.
Enzymes which are generally proteins, speed up the rate of chemical reactions. They have specific three dimensional structures and reduce the energy needed to carry out a chemical reaction (otherwise known as the activation energy). Since the enzymes reduce the amount of activation energy the reaction occurs at a quicker pace. Enzymes do not chemically react with the substrate so they can continually help to convert reactants to products. Changes in pH and salinity negatively affect the enzymes productivity. Another factor in the speed of the reaction is heat. More heat, therefor faster moving enzyme and substrate molecules, causes more collisions and speeds up the reaction. Most enzymes function best at medium temperatures however there are of course exceptions. The enzymes "natural habitat" is a good reflection of what are optimal temperatures for the enzymes to operate under. Another component to the speed of reaction is concentration of molecules. Until the point of excess, enzymes will speed up the reaction if there are more molecules. This knowledge of enzymes will help us in our lab because we are using cellobiase, (an enzyme) to break down cellobiose to glucose. Also our knowledge of how pH, temperature, and concentration affect reactions will come into consideration when we analyze how these affect our break down of cellobiose. This ability to break down celluloses into glucose is used by biofuel industrys in search of an alternative to petroleum. The glucose can be converted to ethonol which can be used to power engines. In our lab we are not trying to solve the worlds pollution problems, merely trying to understand the process. We are going to use cellubiase to break down cellubiose into glucose. During the process we will take part of the solution at different times in the reaction and attempt to use a stop solution to take "snap shots" of the process. Using p-nitro to turn the glucose a color visible to human eyes, we will be able to see glucose in the making. I predict this will be a successful lab but precision will be necessary throughout.
Results/Observations
During the experiment every later interval progressively became a stronger yellow color. In the beginning the yellow was hard to see and closer to a clear color. Towards the end the last tube that we transfered it into turned a very strong yellow color. This was also true when we replaced the enzyme with mushroom extract. The results seemed to be nearly identical to the previous days tubes.
Discussion:
This means that the experiment did end up working. The cellobiose inside the main tube was being broken down into glucose and the results were obvious. It also proved that the mushroom acted just like cellobiase in that it also produced the glucose. Although our lab ended up working errors could have occurred during the process such as maybe a certain mushroom doesn't act like cellobiase. If it didn't break down the cellobiose then the p-nitro would have no glucose to turn yellow and we would have to results to look at.
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