Final answer:
The left side of the heart is responsible for systemic circulation, moving oxygenated blood to the body and returning deoxygenated blood to the heart.
Step-by-step explanation:
The left side of the heart performs the systemic circulation. The systemic circulation is the part of the cardiovascular system which transports oxygenated blood away from the heart to the body, and returns deoxygenated blood back to the heart. In contrast, the right side of the heart deals with pulmonary circulation, which takes deoxygenated blood to the lungs to be oxygenated. Hence, the right side of the heart pumps deoxygenated blood into the pulmonary circuit, while the left side pumps oxygenated blood into systemic circulation.