Two Proteins Bind to the Same Ligand, and Protein a Has

question 40

Multiple Choice

Two proteins bind to the same ligand, and protein A has half of its binding sites occupied when the ligand concentration is 0.5 mM, while protein B has half of its binding sites occupied when the ligand concentration is at 0.3 mM. Which protein binds the ligand more strongly, and what is the dissociation constant for that protein-ligand interaction?

• A) Protein A binds more strongly, and K_d = 0.3 mM.
• B) Protein A binds more strongly, and K_d = 0.5 mM.
• C) Protein B binds more strongly, and K_d = 0.3 mM.
• D) Protein B binds more strongly, and K_d = 0.5 mM.
• E) Both proteins bind the ligand with the same affinity, and K_d = 0.4 mM.

---

Definitions:

Immune Responses

The body's defense mechanism against foreign substances or pathogens, involving recognition and response by the immune system.

Exam Weeks

A period, usually at the end of a semester or academic year, dedicated to administering examinations to students.

Immune System

A complex network of cells, tissues, and organs in the body that work together to defend against foreign invaders and pathogens, such as bacteria and viruses.

Blood Pressure

The force of circulating blood on the walls of blood vessels, used as an important indicator of cardiovascular health.