Question

Which one does not match with regard to biological activity?
A. Creatinine
B. Renin
C. Gastrin
D. Oxytocin

Answer 1

Hint: The biological activities are all those mechanisms or actions that happen in the body resulting in metabolism and catabolism reactions. The biological relevance of the given options should be analyzed keenly to derive the right answer. Also, it should be noticed that one of the following is a product of biological activity.

Complete answer:
Biological activity can be defined as the effect of some chemical over the metabolic functioning of the body’s cells. This effect can be advantageous or disadvantageous. Moreover, every biological activity involves some reactants and some products or byproducts.
Now let us understand each given term to know its biological activity and how they are related.
-Creatinine is released by the body at a constant rate. It is a breakdown product of creatine phosphate. Thus, it is a metabolic waste that is a good indicator of muscle metabolism. It is created by some biological activity in creatine, phosphocreatine, and ATP (Adenosine Triphosphate).
-Renin is an enzyme and a protein that is secreted from kidneys. It is a key regulator in the renin-angiotensin-aldosterone mechanism of sodium ions regulation in the urine. It acts as an arterioles constrictor in hypotension conditions. So, it is a key ingredient in some biological activity.
-Gastrin is a peptide hormone involved in the stimulation of secretion of gastric acid. It is secreted in Duodenum. It is also involved in the secretion of pancreatic juice. Thus, it is a component of an important biological activity.
-Oxytocin is also a hormone that is secreted by the posterior pituitary gland. It functions to regulate uterine contractions that take place during childbirth. Also, it is a key component in the stimulation of milk release from mammary glands during lactation. It is also a component of important biological activity.
-Therefore, the one which does not match with regard to biological activity is creatinine as it is just a biological waste but is not a stimulator of biological activity.
Hence, option A is the right answer.

Note: Although renin and oxytocin are involved in different biological activities, a relation between them can be deduced on some similar functions. High doses of oxytocin can result in low sodium levels creating hypotension conditions that stimulate renin to activate aldosterone release.