What would happen if DNA ligase was not available for DNA replication?
This may destabilize the strand and prevent binding and proper manipulation by other replication enzymes. (b) If DNA ligase was not available the lagging strand and any new segment of DNA would not be attached to the rest of the DNA in the strand. If the strands were to dissociate the DNA would be fragmented.
What would happen if DNA ligase were defective?
What would be the consequence(s) for DNA synthesis if DNA ligase were defective? Lagging strand synthesis would be incomplete; leading strand synthesis would be unaffected.
Which of the following is most likely to result if a cell is unable to produce histone proteins?
If a cell were unable to produce histone proteins, which of the following would be a likely effect? The cell’s DNA couldn’t be packed into its nucleus. DNA polymerase is a directional enzyme that synthesizes leading and lagging strands during replication.
What is PCR used for?
What is PCR? Sometimes called “molecular photocopying,” the polymerase chain reaction (PCR) is a fast and inexpensive technique used to “amplify” – copy – small segments of DNA.
What are the steps of PCR?
PCR is based on three simple steps required for any DNA synthesis reaction: (1) denaturation of the template into single strands; (2) annealing of primers to each original strand for new strand synthesis; and (3) extension of the new DNA strands from the primers.
How is PCR used to diagnose?
The use of Polymerase Chain Reaction (PCR) in infectious disease diagnosis, has resulted in an ability to diagnose early and treat appropriately diseases due to fastidious pathogens, determine the antimicrobial susceptibility of slow growing organisms, and ascertain the quantum of infection.
What are the advantages of PCR diagnosis?
Table 1
| Advantages of PCR | Disadvantages of PCR |
|---|---|
| Shown to be more cost-effective with selective use than culture and staining | Becomes less cost-effective when performed with a multi-organism PCR approach |
| Increased ability to detect less common organisms such as viruses | Supply costs, machinery fees, training expenses |
What is the difference between RT PCR and PCR?
RT–PCR is a variation of PCR, or polymerase chain reaction. The two techniques use the same process except that RT–PCR has an added step of reverse transcription of RNA to DNA, or RT, to allow for amplification.
What are the reagents needed for PCR?
In general, a complete PCR reaction requires five basic PCR reagents; DNA/RNA template, DNA polymerase, primers (forward and reverse), deoxynucleotide triphosphates (dNTPs) and PCR buffers.
What buffer is used in PCR?
PCR is carried out in a buffer that provides a suitable chemical environment for activity of DNA polymerase. The buffer pH is usually between 8.0 and 9.5 and is often stabilized by Tris-HCl. For Taq DNA polymerase, a common component in the buffer is potassium ion (K+) from KCl, which promotes primer annealing.
What temperatures are used in PCR?
The annealing temperature (typically between 48-72°C) is related to the melting temperature (Tm) of the primers and must be determined for each primer pair used in PCR. During the extension step (typically 68-72°C) the polymerase extends the primer to form a nascent DNA strand.