Unit 3-Molecular Genetics Lesson 4 1.0 Flashcards
What is hybridization?
The process of forming double stranded DNA between a single stranded probe and single stranded target DNA.
What is a DNA probe?
A short fragment of DNA that detects complementary sequences in target DNA.
Define annealing in the context of DNA.
The process where complementary sequences of single-stranded DNA or RNA pair through hydrogen-bonding, converting single stranded molecules into double-stranded.
What is the purpose of the Polymerase Chain Reaction (PCR)?
To enable researchers to take very small amounts of DNA and make copies quickly (amplification of DNA).
Who refined the PCR procedure and won a Nobel Prize for it?
Kary Mullis, who won the Nobel Prize in 1993.
What were plasmids used for before the late 1980s?
They were used for DNA amplification before PCR was refined.
How does PCR differ from using plasmids for DNA copying?
PCR is copying DNA directly, while using plasmids is indirect and more time-consuming.
At what temperatures does heat denaturation occur in PCR?
Heat is applied at temperatures of 94°C to 96°C.
What is the role of RNA primers in DNA replication, and how does it differ in PCR?
In DNA replication, RNA primers are used, but in PCR, two DNA primers are utilized.
What are the two types of primers used in PCR?
The forward primer and the reverse primer.
In what direction do primers go in PCR?
Primers must be placed at the 3’ end of each DNA strand and go in a 5’ to 3’ direction.
What temperature range allows primers to anneal in PCR?
The temperature is decreased to the 50 – 65°C range.
What happens after primers anneal in PCR?
The temperature is raised to 72 °C, and Taq polymerase builds the complementary DNA strand with free nucleotides.
Where is Taq polymerase isolated from?
Taq polymerase is isolated from Thermus aquaticus, a bacterium found in hot springs.
How much DNA is needed for PCR to work?
Very small amounts of DNA are needed; even a single strand of hair has enough.
