The Expression of the Tryptophan Operon Is Controlled by A(n)

question 26

Multiple Choice

The expression of the tryptophan operon is controlled by a(n)

• A) repressor that is active when it is alone.
• B) repressor that is inactive when it binds to lactose.
• C) repressor that is active when it binds to tryptophan.
• D) activator that turns the operon on by binding to DNA.

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Definitions:

Active Transport

The process in which molecules travel through a cell membrane from an area of lesser concentration to an area of greater concentration, necessitating the use of energy.

Small Intestine

The small intestine is part of the digestive system, responsible for absorbing nutrients from food through its lining into the bloodstream.

Cholesterol

A waxy, fat-like substance found in the cells of all animals, essential for the formation of cell membranes, certain hormones, and vitamin D.

LDL Receptor

A receptor on cell surfaces that binds low-density lipoproteins, playing a critical role in cholesterol metabolism.