Aprotein called gef-h1 is known to control immune responses to certain viruses such as influenza a. gef-h1 is best classified as which kind of protein?
a structural protein
an antibody
an enzyme
a messenger protein

An antibody

Protein GEF-H1 is an example of an antibody.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.