Question

Because they have similar chemical structures, morphine and heroin are able to lock into receptor sites for

Answer 1

Morphine and heroin have very similar structures, and they are classified into the group of opioids. All of the opioids, including morphine and heroin lock into endorphin receptors in the central nervous system causing a feeling of intense euphoria. 

Answer 2

Answer & explanation:

Morphine and heroin are substances classified as opioids, substances that have effects close to opium or substances present in it, acting on receptor sites with the same name.

Morphine is one of the most potent painkillers, used in treatments for very severe pain, such as postoperative pain or burn pain.

Heroin was developed in laboratory from morphine, which has been used as a medicine for a long time (although banned in many countries) and only after decades has been classified as a harmful drug.

Heroin can cause effects on the human body such as euphoria and temporary feeling of well-being, similar to the effect of endorphin(which is a neurotransmitter). In addition, it has adverse reactions such as skin allergies, impotence and slow reflexes..