Ans: Renin is considered to be one of the major enzymes that is secreted by our kidneys and it controls some of the important functions of the body. Also, there might be a chance that it can be secreted by our placenta of the body. The renin enzyme tends to play a very important role in the physiological functions that tend to take effect in the functioning of the body as well. It is an enzyme that helps in controlling the blood pressure in the body. When it is found in the blood of a human body, renin acts on one particular protein that is called angiotensinogen, and that results in the releasing of angiotensin I.