The release of this ion from the N-lobe of a protein that binds to it is mediated by a pair of hydrogen bonded lysines called the "dilysine trigger." After pH is lowered (15[1])to about 5.4, this [emphasize] insoluble ion dissociates from a complex and is converted into a soluble counterpart by STEAP3. It has nothing to do with cyanide poisoning, but methylene blue reacts with this ion (-5[1])to treat a condition that often (15[1])manifests (15[1])as blue skin. Since (-5[1])this ion is (-5[1])present (-5[1])in (10[1])(*) [emphasize] aerobic (-5[2])environments, bacteria secrete enterobactin and other siderophores (10[2]-5[1])that scavenge (10[1])this ion (-5[2])by binding to it with high affinity. (10[1])Two species of this ion bind to transferrin with an association constant (10[1])of 10 to the negative 22nd. The adjective "ferric" (10[2]-5[1])refers to, (10[2]-5[1])for 10 points, (10[1]-5[1])what metal cation, (0[1]-5[1])a more oxidized form of the ion found at the center of hemoglobin? (10[1]0[1])■END■ (10[7]0[1])