13. Which of the following molecules is an electrolyte normally found in the blood?
Answer: B
Ca2+ is an electrolyte normally found in the blood.
Calcium ions (Ca2+) are essential electrolytes present in the blood, playing critical roles in various physiological processes, including muscle contraction, nerve function, and blood coagulation.
A) H2O
Water (H2O) is not classified as an electrolyte. While it is a vital component of blood and helps dissolve electrolytes, it does not dissociate into ions that can conduct electricity.
B) Ca2+
Calcium ions (Ca2+) are indeed an important electrolyte found in the blood. They are crucial for many bodily functions, including the maintenance of bone health and the regulation of heart rhythms.
C) Lactase
Lactase is an enzyme that helps in the digestion of lactose, but it is not an electrolyte. It does not dissociate into ions and therefore does not perform the electrical functions associated with electrolytes in the blood.
D) Iodine
Iodine is an essential trace element important for thyroid function, but it is not an electrolyte. It does not exist in ionic form in the blood and does not contribute to the electrical conductivity associated with electrolytes.
Conclusion
Ca2+ is the only option listed that qualifies as an electrolyte commonly found in the blood, essential for multiple physiological functions. Other options either do not serve as electrolytes or do not exist in the ionic form required for such classification, confirming that B is the correct answer.