pcr Flashcards
(23 cards)
What does PCR stand for?
Polymerase Chain Reaction
What is the primary purpose of PCR?
To amplify (copy) a specific DNA sequence
What are the key components of PCR?
- Template DNA
- Primers
- DNA Polymerase
- Nucleotides (dNTPs)
- Buffer Solution
What is the role of template DNA in PCR?
Contains the target sequence to be copied
What are primers in the context of PCR?
Short, single-stranded DNA sequences that bind to the target region
What is Taq polymerase?
A heat-resistant enzyme used to build the new DNA strand
What are nucleotides in PCR?
The building blocks of DNA (adenine, thymine, cytosine, guanine)
What is the purpose of the buffer solution in PCR?
Maintains the correct pH and conditions for the reaction
What happens during the denaturation step of PCR?
The sample is heated to break hydrogen bonds, separating the double-stranded DNA into single strands
What is the temperature range for the denaturation step in PCR?
94–98°C
What is the purpose of the annealing step in PCR?
Allows primers to bind to their complementary sequences on the single-stranded DNA
What is the temperature range for the annealing step in PCR?
50–65°C
What happens during the extension step of PCR?
Taq polymerase binds to the primers and adds nucleotides to extend the new DNA strand
What is the temperature for the extension step in PCR?
72°C
How many cycles does PCR typically repeat?
30–40 times
What is the result of each PCR cycle?
Doubles the number of DNA molecules
What are some medical applications of PCR?
- Disease Diagnosis
- Detects viral and bacterial infections
- Detects genetic mutations
What is DNA fingerprinting in forensic science?
Amplifies STR markers in crime scene samples for suspect identification
What is an application of PCR in evolutionary biology?
Extracts and amplifies ancient DNA from fossils
What is cross-contamination in PCR?
Mixing of DNA samples leading to false-positive results and inaccurate conclusions
True or False: Taq polymerase was originally found in Thermus aquaticus.
True
Fill in the blank: PCR is used in _______ biology research.
molecular
What is one impact of cross-contamination in forensic DNA testing?
Wrongful convictions or failure to identify the correct suspect
