Question

Briefly describe the major steps of the mechanism of how a competent bacterial cells becomes transformed, beginning with the binding of transforming DNA from a donor cell to the surface of the recipient cell, and ending with the resulting transformed cell which is now genetically altered relative to the parental cell Do NOT describe the definitions of transformation, transformed cell, competent, or competency.

Answer 1

Answer:

The steps can be the following:

1. Free DNA fragments from the donor cell bind to the recipient cell.

2. A DNA strand is digested by the bacterial nuclease and the excess strand is absorbed.

3. The coated DNA and the DNA of the recipient cell are brought together to achieve a homologous sequence.

4. DNA base pair alignment occurs through DNA ligase.

5. The integration of the exogenous DNA resulting from the recombination is completed, completing the transformation.

Explanation:

Transformation can be said to be the genetic variation of a cell that results from the uptake, incorporation and expression of exogenous DNA from its environment, which is absorbed by the cell membrane. The recipient bacteria have to be in a state of competition, and this type of competition can be induced in a laboratory, so that the bacterial cell is permeable to DNA when exposed to certain conditions. For this, the cells are incubated in a solution that has various divalent cations, such as calcium chloride, before exposing them to thermal shock. The main function of calcium chloride is to alter the cell membrane, allowing the recombinant DNA to enter the host cell. These types of cells can be called as competent cells.