WGU Biochemistry Final Review (all answered)

1. The polymerase chain reaction is a tool used to study protein structure. True False correct answers False Feedback PCR is a tool used to amplify a specific segment of DNA. What color is the primer in the following diagram? Red Purple Blue correct answers Red Feedback Recall from the section on DNA replication that DNA polymerase needs a primer to begin DNA synthesis. This requirement means the primers will direct the DNA polymerase to only synthesize complementary strands of the target DNA. (Note: In DNA replication, the primers are RNA primers, while PCR generally uses DNA primers because they are more stable.) dNTPs are DNA nucleotides used in PCR. True False correct answers True Feedback dNTPs stands for deoxynucleotide triphosphates, which are the nucleotides used in DNA synthesis. A thermocycler is a machine used for PCR that varies the temperature of a sample. True False correct answers True Feedback For PCR, in each cycle, the two strands of the duplex DNA are separated by heating, then the reaction mixture is cooled to allow the primers to anneal (or pair) to their complementary segments on the DNA. Next, the DNA polymerase directs the synthesis of the complementary strands. The use of a heat-stable DNA polymerase eliminates the need to add fresh enzyme after each round of heating (heat inactivates most enzymes). Hence, in the presence of sufficient quantities of primers and dNTPs, PCR is carried out simply by cycling through the different temperatures for strand separation, primer annealing, and DNA synthesis. The thermocycler is the machine that is used to vary the temperature of the samples.