tonykwok

hello, PhospholipaseA2 is a enzyme that cleaves fatty acids (principally arachidonic acid) from the second position (F2) of phospholipids, and arachidonic acid is the precursor of Prostaglandins(PG) and Thromboxane (TX). We know DAG(diacylglycerol) is important in the G-protein linked intracellular signal transduction ( in the Proteinlipase C (PLC) pathway, PIP2 is breaked into DAG and IP3 with the catalyse of PLC), 1- Why it was said that DAG (diacylglycerol) is the precursor of PG ?(http://www.answers.com/diacylglycerol?gwp=12&method=2) 2- is there any relation between Proteinlipase A2 and the synthesis/dissociate of DAG. 3- What (if there is ) role does PLA2 play in the intracellular signal transduction ?

As we know, some metal ions like Calcium ion , potassium ion and sodium ion are colorless, while Cobalt ion, Iron(II)/(III) ion have color. Why ? What is the physical nature beneath that phenomenon ? What theories are involved ?

Hi, Is there anybody can give me the strict definition of the following terms?(in terms of genetic) 1. mitosis 2. dorminant character 3. recessive character