If the lacl gene is mutated so that the repressor protein no longer binds to lactose, what will be the effect on the expression of B-galactosidase in lactose's presence and absence? Explain.

In the regulation of the tryophan operon in bacteria, the co-occurence of transcription and translation plays a key role regulating full activation of operon expression. Diagram and explain how during the conditions of high tryptophan concentration this system regulates the expression of genes in the operon.

The lac operon consisting of lacl, lacZ and lacY genes in addition to all the transcripton factors is used to modulate the level of lactose in the cell. Please describe the cycle of fluctuations in lactose levels and why they occur by referencing the specific components. If glucose is a byproduct of this process, how are the glucose levels in relation to the lactose level fluctuations and the reason for those fluctuations?

During periods of sustained demand and in the presence of sufficient nutrients, muscle cells can increase in size. When the size of muscle cells increases, they will often develop additional nuclei in their intracellular environment. Which of the following is the most likely explanation for the expression of additional nu- clei in growing muscle cells? A B с D Nutrients entering the cells will be digested and recycled more quickly by the additional nuclei to better support the subcellular components in the cell as its size increases. The ATP molecules that are produced in the additional nuclei will be able to better sup- port the increased energetic demands on the muscle cell as its size increases. The addition of more nuclei to the cell will allow more genetic information to be stored in the cell and allow the cell to produce additional types of proteins as its size increases. Additional nuclei allow subcellular components to continue to be sufficiently expressed and transferred…

What does it mean to study the subcellular localization of a protein? What are two techniques that could be used to study the subcellular localization of a protein? Then specify how each of these techniques could be used to study a transcription factor in liver cells