Fresh red meat, such as beef, has a red color because of the Fe2+ found in hemoglobin. When cells die, this iron oxidizes to Fe3+, giving the meat a brown color. Sometimes, grocers and butchers suffuse meat with carbon monoxide to make it appear fresher because when CO binds to the heme in hemoglobin, it gives the meat a red color.
A particular genomic caretaker protein, Protein X, has an affinity for both Ligand Y and Ligand Z. When you have 0.23 microM of Protein X in a solution and mix it with 0.11 microM of Ligand Y, the resulting solution contains 0.20 microM of free Protein X, 0.09 microM of free Ligand Y, and 0.02 microM of the protein-ligand complex, after equilibrium has been reached. However, when you have 0.23 microM of Protein X in a solution and mix it with 0.11 microM of Ligand Z, the resulting solution contains 0.14 microM of free Protein X, 0.02 microM of free Ligand Z, and 0.09 microM of the protein-ligand complex, after equilibrium has been reached. Which ligand has a greater affinity for Protein X?
a. Ligand Y
b. Ligands Y and Z have equal affinity for Protein X.
c. Ligand Z
d. It is not possible to determine with the given information.