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Biotech Lab#2 DNA ScissorsExtract DNA from cell
Magnify a portion of DNA & it looks like this: Double Helix
Magnify a portion of Double Helix & it looks like this:
ATCGGACGTACGGGG
TAGCCTGCATGCCCC
This is a sequence of nucleotides. How many nucleotides? 30How many bases? 30 How many base pairs? 15 This segment represents a gene.
The “Gene”• A gene is a segment of DNA with a specific sequence of
nucleotides.• A gene is associated with an organism’s trait.• A gene provides the information to make a protein that determines
what an organism can do or look like. Proteins can be one of many types.
Types of Proteins• Transport - hemoglobin• Receptor - membrane protein• Storage - albumin• Signal - insulin• Contractile - actin, myosin• Enzyme - catalase• Structural - collagen
Molecular Biologists will• Want to be able to remove the gene from the DNA• Want to take the gene and put it in another area of the DNA
or in another organism’s DNA• Let’s review DNA structure to complete this lab: DNA Scissors
DNA is antiparallel• Antiparallel means that
the two strands run in opposite direction.
• One strand runs in the 3’ to 5’ direction and opposite strand runs in the 5’ to 3’ direction.
• Diagrams to right illustrate antiparallel…look at the arrows.
Why is one end 3’ and the other 5’?• Look at the 3’ end.
Notice the black line which represents a bond. What functional group belongs here?
• Look at the 5’ end. What functional group is bonded to the 5’ carbon?
DNA Scissors
This lab is about special enzymes that will cut DNA into smaller fragments.This lab will simulate how a specific enzyme cuts the DNA.This lab shows how to prepare DNA for future use.
Restriction Enzymes• Enzymes that catalyze a reaction that will cut the DNA at a
specific location• The location on the DNA is called the restriction site• A restriction site has a specific sequence of nucleotides called
a palindrome “RACECAR”
Pieces of DNA
The picture shows the (4) strips of DNA that will be used to simulate the action of a restriction enzyme.
Answer these three questions:1. What type of cut is #1? #2?
2. Identify an enzyme that can make a cut like cut#1.3. What is the palindrome sequence for cut #1?
Now do the lab……..• Read each step carefully.• Answer questions within a step on the lined paper.• Upon completion, tape DNA strips to a piece of colored paper.• Each table will submit each person’s work as a group.
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