Explain the difference between active transport and facilitated transport

Active transports needs energy to transport against the concentration gradient from low to high . Proteins act as a carriers that use energy from ATP directly called primary transport ( the Na+ / K+ ATpase transport 2 potassium and 3 sodium in opposite directions) or indirectly via other ion ingredient called secondary transport (involves coupling the molecules with another moving along an electrochemial gradient)  

Facilitated transport (diffusion) in which substances move down the concentration gradient from high to low, they includes proteins such as ion channels ( that provide a water filled pore for hydrophilic ions or carriers for large molecules such as glucose).

d. the weight of the book

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.