DNA Replication -
Objectives: Students draw DNA to demonstrate semi-conservative replication.
Instructions: Replicate the portion of the DNA molecule shown below. To indicate that DNA replication is semi-conservative, label the 'original' (the side of the DNA that came from the original molecule) and 'new' strand on each of the two new DNA molecules formed.
Specific Suggestions: Visualize the action of DNA helicase separating the complementary base pairs and new nucleotides filling the vacancies due to the action of DNA polymerase and DNA ligase. They will form two "part old and part new" molecules of DNA.
Key to the Letters
- P - Phosphate
- S - Ribose Sugar
- A - Adenine
- C - Cytosine
- G - Guanine
- T - Thymine
ORIGINAL MOLECULE REPLICATED MOLECULES
5'
P
S-A=T-S
P P
S-C=G-S
P P
S-T=A-S
P P
S-G=C-S
P P
S-G=C-S
P P
S-A=T-S
P
3'
Complete the following:
- On the original DNA molecule, draw a box around one complete nucleotide.
- On the new strand of either replicated DNA molecule, circle a DNA triplet
- Which cellular organelle would contain this DNA molecule?
- Describe the structure of DNA.
- What is the function of DNA?
- What enzymes are associated with DNA replication?