Polymerase Chain Reaction (PCR) and Microbial Genetics

These flashcards cover key concepts regarding Polymerase Chain Reaction (PCR), microbial genetics, and marker genes, helping students prepare for their exam.

What does PCR stand for?

Polymerase Chain Reaction

What is the main application of PCR?

To amplify small segments of DNA.

What organism does Taq Polymerase come from?

Thermus aquaticus.

What are the three main steps of each round of PCR?

Denaturation, Annealing, Extension.

What temperature is the initial denaturation performed at in PCR?

95°C for 3 minutes.

What is the purpose of primers in PCR?

To locate target DNA fragments for amplification.

Which gene is commonly used as a marker for comparing microbes?

16S rRNA.

What is the significance of 16S rRNA sequencing?

It reveals the evolutionary relationships between different microorganisms.

Who proposed the use of 16S rRNA as a tool for comparing microbes?

Carl Woese.

What are the components of the PCR master mix?

Taq Polymerase, dNTPs, Polymerase Buffer, and Primers.

What is a molecular clock in phylogenetics?

It is a method for estimating the time of divergence between species based on genetic mutations.

What are marker genes?

Specific genes used to identify and classify organisms based on genetic similarities.

What is the purpose of EDTA in the Polymerase Buffer?

To act as a chelating agent and keep DNA intact.

What is the universal tree of life based on?

Phylogenetic relationships among the three domains of life: Archaea, Bacteria, and Eukarya.

What happens during the annealing step of PCR?

Primers bind to the complementary sequences on the DNA template.

What temperature is the annealing step of PCR conducted at?

56°C for 30 seconds.

What does the final extension step of PCR involve?

Extending any remaining single-stranded DNA at 72°C for 5 minutes.

What is the purpose of KCl in the Polymerase Buffer?

To neutralize the charges in the DNA template.