Embedded Files
INTRODUCTION
My project is about the extraction of DNA from strawberries. The driven questions for my project are; what procedure is used to extract DNA from cells strawberries and how does each step of the procedure help in isolating DNA from other cellular material?
MATERIALS
•Rubbing alcohol
•Small bowl
•1/2 teaspoon salt
•1/3 cup water
•1 Tablespoon dishwashing detergent
•3 strawberries (green tops removed)
•Small plastic zip-top bag
• a coffee filter
•plastic up
•Test tube
•rubber band (optional)
PROCEDURE 1. Put the rubbing alcohol in the freezer to chill it while you prepare the rest of the experiment.
2.Mix the salt, water and detergent in a small bowl. This is the extraction liquid.
3. Put the strawberries in the plastic bag and squeeze out all the extra air before sealing tightly.
4.Mash the strawberries with your hands for about 2 minutes until they are mushy.
5.Add 3 tablespoons of the extraction liquid to the strawberries in the bag. Squeeze out the air and seal the bag again.
6.Mash the strawberry mixture with your hands for another minute.
7.Place the coffee filter on top of the cup to make sure it's in place you can hold it or put a rubber band around the filter.
8.Pour the strawberry mixture from the bag on to the coffee filter. Let it drop through the cheesecloth until there is no liquid left.
9.Throw away the filter and the chunks of strawberry in it.
10.Pour the contents of the glass into the test tube or small jar until it is 1/4 full.
11.Tilt the test tube or jar and very slowly pour rubbing alcohol down the side. The alcohol will form a layer on top of the strawberry juice. Do not let the alcohol mix with the strawberry juice!
12.Let the contents sit for a few minutes. You should see stringy, whitish stuff collecting between the two layers of liquid. That is DNA.
SCIENTIFIC PRINCIPLE
My hypothosis for my experiment was through the procedure I used i would be able to extract DNA from the strawberries and I was able to at the end of the experiment. These are the reasons why DNA was able to be extracted from strawberries. DNA is held inside the nucleus of cells. To free DNA from the nucleus, it will be necessary to breakdown the membranes of the cells. The membranes are made up of phospholipids,and can be dissolved by using a detergent. Table salt, which helps eliminate the proteins, called histones, that DNA is wrapped in. DNA is soluble in water and invisible, though when it's alcohol it becomes insoluble and becomes visible.
Question
What procedure is used to extract DNA from cells strawberries? How does each step of the procedure help in isolating DNA from other cellular material?
Design/Plan
1. Put the rubbing alcohol in the freezer to chill it while you prepare the rest of the experiment.
2. Mix the salt, water and detergent in a small bowl. This is the extraction liquid.
3. Put the strawberries in the plastic bag and squeeze out all the extra air before sealing tightly.
4. Mash the strawberries with your hands for about 2 minutes until they are mushy.
5. Add 3 tablespoons of the extraction liquid to the strawberries in the bag. Squeeze out the air and seal the bag again.
6. Mash the strawberry mixture with your hands for another minute.
7. Place the coffee filter on top of the cup to make sure it's in place you can hold it or put a rubber band around the filter.
8. Pour the strawberry mixture from the bag on to the coffee filter. Let it drop through the cheesecloth until there is no liquid left.
9. Throw away the filter and the chunks of strawberry in it.
10. Pour the contents of the glass into the test tube or small jar until it is 1/4 full.
11. Tilt the test tube or jar and very slowly pour rubbing alcohol down the side. The alcohol will form a layer on top of the strawberry juice. Do not let the alcohol mix with the strawberry juice.
12. Let the contents sit for a few minutes. You should see stringy, whitish stuff collecting between the two layers of liquid. That is DNA.
Investigation
DNA is held inside the nucleus of cells. To free DNA from the nucleus, it will be necessary to breakdown the membranes of the cells. The membranes are made up of phospholipids, and can be dissolved by using a detergent. Table salt, which helps eliminate the proteins, called histones that DNA is wrapped in. DNA is soluble in water and invisible, though when it's alcohol it becomes insoluble and becomes visible.
Purpose
To extract DNA from strawberries.
Materials
•Rubbing alcohol
•Small bowl
•1/2 teaspoon salt
•1/3 cup water
•1 Tablespoon dishwashing detergent
•3 strawberries (green tops removed)
•Small plastic zip-top bag
• A coffee filter
•plastic up
•Test tube
•rubber band (optional)
Procedure
1. Put the rubbing alcohol in the freezer to chill it while you prepare the rest of the experiment.
2. Mix the salt, water and detergent in a small bowl. This is the extraction liquid.
3. Put the strawberries in the plastic bag and squeeze out all the extra air before sealing tightly.
4. Mash the strawberries with your hands for about 2 minutes until they are mushy.
5. Add 3 tablespoons of the extraction liquid to the strawberries in the bag. Squeeze out the air and seal the bag again.
6. Mash the strawberry mixture with your hands for another minute.
7. Place the coffee filter on top of the cup to make sure it's in place you can hold it or put a rubber band around the filter.
8. Pour the strawberry mixture from the bag on to the coffee filter. Let it drop through the cheesecloth until there is no liquid left.
9. Throw away the filter and the chunks of strawberry in it.
10. Pour the contents of the glass into the test tube or small jar until it is 1/4 full.
11. Tilt the test tube or jar and very slowly pour rubbing alcohol down the side. The alcohol will form a layer on top of the strawberry juice. Do not let the alcohol mix with the strawberry juice.
12. Let the contents sit for a few minutes. You should see stringy, whitish stuff collecting between the two layers of liquid. That is DNA.
Analysis and conclusion
My hypothesis for my experiment was through the procedure I used I would be able to extract DNA from the strawberries and I was able to at the end of the experiment. These are the reasons why DNA was able to be extracted from strawberries. DNA is held inside the nucleus of cells. To free DNA from the nucleus, it will be necessary to breakdown the membranes of the cells. The membranes are made up of phospholipids, and can be dissolved by using a detergent. Table salt, which helps eliminate the proteins, called histones, which DNA is wrapped in. DNA is soluble in water and invisible, though when it's alcohol it becomes insoluble and becomes visible.
Application
DNA extraction can be used for many reasons. To gather DNA that’s required to perform a paternity test or to extract it from people and samples found at crime scenes. The DNA can be compared to identify potential suspects and possibly free people who are wrongly accused of crimes. DNA extraction can also be used by physicians to test for genetic diseases in adults.
Extension questions
1. Many models of DNA look like a spiral staircase, or twisted ladder. What makes up the steps, or rungs, of the double helix? What are the components of the handrails, or sides, of the double helix?
Each rung is made up of two nitrogen basis, paired by hydrogen bonds. The components of the sides are alternating sugar and phosphate groups.
2. If a DNA sequence is written as: TACCGAATCGGATC, what do these letters represent? What part of the DNA structure is not represented when writing only the sequence?
The letters represent (T) THYMINE, (C) cytosine, and (G) guanine the four nitrogen bases found in nucleotides that form a strand of DNA. The RNA structure is not represented when writing this sequence.
3. What type of bond holds the two strands together? Relative to other chemical bonds, is this type of bond strong or weak? Why is this an important aspect of the DNA structure?
The DNA double helix is held by hydrogen bonds. This is important because the weak bond makes it easier during replication to separate the strands.
4. How does DNA determine the traits of an organism, such as blood type or hair color?
DNA is the code within the cells of an organism that acts as the blueprint for how the rest of the cells should reproduce and form within organisms.
5. How does "complementary base pairing" relate to DNA replication? Summarize how replication occurs in cells.
Complimentary base pairing allows new DNA strands to be synthesized in replication. As the DNA strands unwind and separate, new complimentary strands are produced by the hydrogen bonding of free DNA nucleotides with those on each parent strand. Enzymes called, DNA Polymerases, join the nucleotides by way of phosodiester bonds.
6. DNA is now commonly used as evidence collected and presented in criminal cases. Suppose a blood stain from the crime scene is sent to a lab for DNA analysis. At the police station, cheek cells are collected from a suspect and submitted for DNA analysis. If the blood came from the suspect, will the DNA from the blood cells match the DNA in their cheek cells? Why or why not?
Yes, because DNA is found in every nucleated cell in the body is the same in all nucleated cells.
7. How much DNA is in a human cell? How is DNA stored within cells? What must be done to extract DNA?
In a human cell if DNA was stretched would measure approximately 6.5 feet. DNA is stored as a code made up of four chemical bases. The first step to extract DNA is to break open the cell. After the cells have been broken open, add a salt solution containing the compound sodium dodecyl sulfate. These solutions break down and emulsify the fat and proteins that make up a cell membrane. Then ethanol is added because DNA is soluble in water. The alcohol causes DNA to settle out of the solution, leaving behind all the cellular components that aren’t soluble in alcohol. Then DNA can finally be extracted.
8. What is a "genetically modified organism" (GMO)? How can the genetic material of an organism be altered?
Genetically modified organisms are whose DNA changed humans using genetic engineering. Using genetic engineering scientist can alter an organism’s genetic material which involves combining strands of DNA from different sources to create a new DNA molecule. The new DNA molecule has a different combination of genes than that which occurs naturally. The newly created DNA is then inserted into a living organism, egg, or sperm, resulting in a genetically modified organism.
9. Refer to the diagram below of the "genetic code". Explain the relationship between genes and proteins, and describe how the information encoded in DNA is used within cells.
Most genes contain the information require to make proteins. To convert genes to proteins is a complicated process and is controlled within each cell. It consists of two major steps – transcription and translation. Together, these two steps are known as gene expression. DNA carries all of the information for your physical characteristics, which are determined by proteins. DNA contains the instructions for making a protein. IN DNA, each protein is encoded by a gene, a specific sequence of DNA nucleotides that specify how a single protein is made.
Page updated
Google Sites
Report abuse