Question

The reaction mixture for pcr is missing the enzyme taq polymerase. which step of pcr would this affect? a. extraction of dna b. denaturation of dna c. binding of primer d. preservation of dna e. elongation

Answer 1

The absence of Taq polymerase in a PCR reaction mixture affects the elongation step, preventing the synthesis of new complementary DNA strands.

Step-by-step explanation:

The absence of Taq polymerase in the PCR (Polymerase Chain Reaction) mixture primarily affects the elongation phase of the PCR process. Option E is correct . During this phase, Taq polymerase is responsible for adding nucleotides to the primers, which allows the creation of new DNA strands that are complementary to the original DNA template. Without Taq polymerase, the elongation step cannot occur, and the PCR will not yield any amplified DNA. It's important to note that Taq polymerase is a thermostable enzyme, meaning it is able to withstand the high temperatures used during the denaturation and annealing steps of PCR, which form part of the reason it is used in this molecular biology technique.

Answer 2

The absence of Taq polymerase in the PCR reaction mixture would primarily affect the step of elongation Therefore the final option is e..

Step-by-step explanation:

The Polymerase Chain Reaction (PCR) involves three main steps: denaturation, annealing, and elongation. During the elongation step, the Taq polymerase enzyme is crucial as it synthesizes new DNA strands by adding complementary nucleotides to the DNA template. The absence of Taq polymerase would impede the elongation process, preventing the synthesis of new DNA strands. As a result, the reaction would be unable to proceed effectively towards the amplification of the target DNA sequence.

In PCR, during elongation, the temperature typically ranges around 72°C. Taq polymerase, derived from Thermus aquaticus, is highly active at this temperature, making it essential for the elongation phase. Without this enzyme, the reaction cannot progress to form new DNA strands, hindering the replication of the target sequence.

The other steps of PCR - extraction of DNA, denaturation of DNA, binding of primer, and preservation of DNA - occur prior to elongation and are not directly reliant on the presence of Taq polymerase. These steps prepare the DNA template and primers for the elongation phase, where the Taq polymerase plays a pivotal role in the amplification process. Therefore, the absence of Taq polymerase mainly impacts the elongation step, preventing the synthesis of new DNA strands essential for amplification.Thus the final option is e.