1. May 27, 2010
Donkey G D V T K G K K I G V Q K C A Q G H T V E K G G K H K T G
Pig…………….G D V T K G K K I F V Q K C A Q G H T V E K G G K H K T G
Dog G D V E K G K K I T V Q K C A Q C H T V E K G G K H K T G
PICK UP A COPY OF THE AMINO ACID SEQUENCES FROM THE FRONT TABLE.
Use the amino acid sequences to determine which of the organisms is most closely related. (each letter represents an amino acid)
2. What is the role of antibodies in your immune system?

2. Day 3: DNA Evidence
What do we know about DNA?

3. DNA Evidence
To separate strands of DNA, we use a process called gel electrophoresis
Uses electrical current!

4. Step 1: Prepare DNA Cut DNA using restriction enzymes
These enzymes are SPECIFIC for where they cut
Example: cut between the A and G of the sequence AAGT
This creates pieces of DNA with different sizes
Similar DNA will have similar pieces
Tag DNA with chemical dyes
Visible under UV light

5. STEP 2: Load Gel (submersed in salt water)
Use a pipette to place cut/stained DNA into WELLS of electrophoresis gel
Gel is like a “forest” of material
DNA will move in between the “trees” to get to the other end

6. STEP 3: Run Gel DNA is negative (phosphate backbone)
Wells are at negative end of gel
DNA wants to move toward other end
DNA will move like a snake through the gel
Small pieces move fastest and furthest (like a squirrel)
Large pieces have a hard time fitting/maneuvering (like an elephant)

8. STEP 4: Read Gel Look at patterns of bands
Same size fragments land in same spot, so darker and thicker band left behind
More bands in common= more closely related

10. Last page of Lab

11. Page 3 of lab