Replication of DNA

Key Area 2

Name of the enzyme that replicates strands of DNA

DNA polymerase

Name of a molecule that must be present for DNA replication to take place

Primers

Describe the role of DNA polymerase during DNA replication

Replicates DNA nucleotides in a 5’ to 3’ direction

Give one practical of PCR

Forensic science

During PCR the sample is heated to around 95°C. State what happens to the DNA at this temperature

Hydrogen bonds between bases are broken and strands of DNA are separated

During PCR, the temperature is lowered to approximately 50-60°C after the DNA strand have separated. State what happens at this stage

Primers to anneal to their complementary target sequences

Explain why a heat tolerant DNA polymerase is required during PCR

So it doesn’t denature due to high temperature used in PCR

During PCR, DNA is heated to between 70-80°C. State what happens at the DNA at this temperature

For heat tolerant DNA polymerase to replicate the region of DNA

State the role of primers during PCR

Indicates a starting point for DNA polymerase to being replication

State on commercial use of PCR

Settle paternity suits

Explain why DNA polymerase produces a lagging strand during DNA replication

DNA polymerase replicates in a 5’ to 3’ direction only

State what happens after the heat tolerant DNA polymerase to replicate the region of DNA

The cycle continues to increase the number of copies of DNA