1.2 Flashcards
What is the basic structure of DNA?
DNA is a double stranded helix composed of repeating molecules called nucleotides.
What are the components of a nucleotide?
A nucleotide is composed of:
* a deoxyribose sugar
* a phosphate
* a nitrogenous base.
What role do hydrogen bonds play in DNA?
Hydrogen bonds hold the nucleotide bases together between the two strands of DNA.
What does PCR stand for?
Polymerase Chain Reaction.
What is the purpose of PCR?
PCR amplifies DNA using complementary primers for specific target sequences.
What are the three main stages of DNA replication in PCR?
- Stage 1: DNA is heated to separate the strands
- Stage 2: Cooled to allow primers to bind
- Stage 3: Heated for DNA polymerase to replicate.
At what temperature range does DNA separate during PCR?
Between 92°C and 98°C.
At what temperature range do primers bind to target sequences during PCR?
Between 50°C and 65°C.
What is the function of heat-tolerant DNA polymerase in PCR?
It replicates DNA at temperatures between 70°C and 80°C.
What are practical applications of PCR?
- Solving crimes
- Settling paternity cases
- Diagnosing genetic disorders.
Fill in the blank: The _______ is the strand that serves as a template for DNA replication.
[template strand]
True or False: DNA polymerase adds nucleotides to the 5’ end of the new DNA strand.
False.
What is the directionality of DNA strands during replication?
Strands are antiparallel.
What are the two types of DNA replication strands mentioned?
- Leading strand
- Lagging strand.
How is the lagging strand replicated?
The lagging strand is replicated in fragments.
