This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: General anatomy, Subject name: Anatomy
All are second messenger except 
Select and explain. 
A. Cyclic AMP, B. Gaunylyl cyclase, C. Diacycglycerol, D. Inositol triphosphate
B: Gaunylyl cyclase
Answer: B: Gaunylyl cyclase 
Explanation: remember that guanylyl cyclase an enzyme while cGMP is a secondary messenger Types ot secondary messenger are There are three basic types of secondary messenger molecules Hydrophobic (DAG) Hydrophilic(cAMP) Gases(NO) Ref-KDT 7/e p47,48