Since it is a light-absorbing pigment, chlorophyll is called a photoreceptor. Also note that there are two types of chlorophyll: chlorophyll a and chlorophyll b. Function. Chlorophyll molecules are contained inside chloroplasts, which are the food producers of the cell found
Calcitonin has an opposite effect, as it decreases the levels of calcium in the blood. Overall, PTH has a strong effect on the blood concentration of calcium, whereas calcitonin has a more moderate effect and is not critical in helping the body maintain normal blood calcium levels.
calcitonin. a polypeptide hormone secreted by the parafollicular or C cells of the thyroid gland, which is involved in plasma calcium homeostasis. It acts to decrease the rate of bone resorption. peptide hormone, of which eight forms are known; produced by the parathyroid, thyroid, and thymus glands; its action is opposite to that of parathyroid hormone in that calcitonin increases deposition of calcium and phosphate in bone and lowers the level of calcium in the blood.