#1, they remain outside the target cell. #2, bind to the receptors inside the target cell. #3, they have no target cells. #4, are made of proteins.
Answer:
Left Atrium
Explanation:
The left atrium is the upper right chamber of the heart. The left atrium receives oxygenated blood from the lungs and pumps it down into the left ventricle which delivers it to the body.
I hope this helps you :)
Answer:
abstain, or refrain from, sexual activity
It’s responsible citizenship
