Question

The human hexokinase enzyme has the same function as the bacterial hexokinase enzyme but is somewhat different in its amino acid sequence. You have obtained a mutant bacterial strain in which the gene for hexokinase and its promoter are missing. If you introduce into your mutant strain a DNA plasmid engineered to contain the coding sequence of the human hexokinase gene, driven by the normal bacterial promoter, the resulting bacteria will now produce: a) the bacterial form of hexokinase. b) the human form of hexokinase. c) a hybrid enzyme that is partly human, partly bacterial. d) both forms of the enzyme.

Answer 1

When a mutant bacterial strain lacking the bacterial hexokinase gene and its promoter is engineered with a human hexokinase gene driven by a normal bacterial promoter, it will produce the human form of hexokinase.

Step-by-step explanation:

Introducing the human hexokinase gene into a mutant bacterial strain that lacks the bacterial hexokinase gene and its promoter, with the human gene being driven by a normal bacterial promoter, will produce the human form of hexokinase. The bacteria will express the introduced gene as it does its own, utilizing the components of molecular machinery it has for gene expression. As a result, the bacteria will synthesize the human version of the enzyme because they're using the human hexokinase DNA sequence to make the protein. There will not be production of the bacterial form of hexokinase, nor a hybrid enzyme, and since only the human gene sequence is present, both forms of the enzyme will not be present.

Answer 2

b) the human form of hexokinase.

Step-by-step explanation:

According to the given information, the amino acid sequences of bacterial and human hexokinase enzyme are different. When a human hexokinase gene sequence is introduced into a mutant bacteria that lack its own hexokinase gene sequence, the resulting bacteria will produce the human form of hexokinase. This is due to the fact that the introduced sequence was from the human hexokinase gene.

Promoters serve as binding sites for RNA polymerase to facilitate gene transcription. Therefore, the presence of a normal bacteria promoter would allow the transcription of the human hexokinase gene in the mutant bacteria.