What molecule is this?

Nucleotide

Explanation:

A Nucleotide is made out of a phosphate group, 5-ringed sugar, and a nitrogenous base, all of which are present in the image. Here the nitrogenous base appears to be adenine so it is the nucleotide derived from adenine.

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.

the tricuspid valve is present between right atrium and right ventricle