Nucleic Acid Based Microbe Identification:PCR

Question 1

What gives an organism its innate characteristics?

Answer 1

• proteins

- RNA molecules

Question 2

What does NAAT stand for and what does it determine?

Answer 2

-Nucleic acid amplification test

• looks for the target DNA or RNA sequences that are specific to a microorganism
  
  • if target sequence is present, its copied repeatedly by the test enzymes

Question 3

What is an example of a NAAT test? (The one used in class)

Answer 3

-PCR test/polymerase chain reaction

Question 4

What is a short sequence of DNA called?

Answer 4

-primer/probes

Question 5

What is the target DNA/RNA sequence called?

Answer 5

-template

Question 6

What does amplification mean in the NAAT test?

Answer 6

-the process of repeatedly copying a target nucleic acid sequence

Question 7

What happens during the first temp phase of the PCR cycle?

Answer 7

• sample mixture is heated to a high temp (ex.94*C)

- any DNA present in the same-le is melted or denatured into 2 single strands

Question 8

What happens during the second temp phase of the PCR cycle?

Answer 8

• temp is lowered (50- 65*C)

- primers may bind to exposed bases on any s.s DNA present if they are complimentary

Question 9

What happens during the third temp phase of the PCR cycle?

Answer 9

• temp is increased to optimal temp for the heat stable DNA polymerase enzyme (72*C)
  
  • DNA polymerase builds new DNA complimentary to the template

Question 10

What are dNTPs?

Answer 10

• deoxyribonucleotide triphosphates

- raw building blocks that the DNA polymerase uses to build DNA

Question 11

What happens in DNA gel electrophoresis?

Answer 11

• DNA molecules are exposed to an electrical field (placed between 2 electrodes)
  
  • the DNA molecules are negatively charged as they move towards the positive electrode and away from the negative electrode
  • this allows the DNA molecules move throught the network of inert polymers

Question 12

Bacterial vs Viral genome

Answer 12

Bacteria:

- single, circular chromosome
- metabolism
- more complex
- multiply slower
- living

Virus:

- Non -cellular
- no metabolism
- simpler DNA
- multiply faster than bacteria
- non living