Download DNA Extraction Prelab

DNA Extraction Pre-Lab
Cell Review
Deoxyribonucleic acid (DNA) is the genetic material in living things. DNA is a very long,
thin molecule that lives in the nucleus of eukaryotic cells. Recall that eukaryotic cells (e.g. plant
and animal cells) have a nucleus while prokaryotic cells (e.g. bacteria) do not. The nucleus of a
eukaryotic cell is the control center of the cell, and it is surrounding by the nuclear envelop
(nuclear membrane). Like the cell membrane, which surrounds the entire cell, the nuclear
envelop is composed of lipids. Lipids are macromolecules and include fats and oils.
Lab Overview
When you complete the DNA extraction lab, you first will have to smash a piece of fresh
fruit in a plastic bag to break apart the cells more easily. You will then add a shampoo mixture
to the fruit so that the shampoo can break apart the lipids in the cell, thereby emptying the
contents of it. In the next part of the procedure, you will strain the fruit / shampoo mixture to
separate the genetic material from the rest of the cellular debris. In the final step, you will
slowly add cold rubbing alcohol to the strained DNA. The charges in the rubbing alcohol and the
DNA are the same, so they begin to repel each other. This causes the DNA to fold onto itself,
forming a clump.
1. What is the full name of the genetic material in a cell?
2. What is the difference between a prokaryotic and a eukaryotic cell?
3. Sketch a picture of a eukaryotic cell below. Label the location of the nucleus, nuclear
envelop and DNA!
4. What is a lipid?
5. Why is shampoo added to the smashed fruit?
6. Why is the fruit mixture strained?
7. Why is the DNA only visible when mixed with the rubbing alcohol?
8. Why do you think you must use a fresh piece of fruit?
9. Why do you think we use fruit for this lab instead of our own cells?