What transports oxygen
depleted blood to the
lungs to exchange co2
for o2?

Red Blood Cells

Explanation:

Oxygen is one of the substances transported with the assistance of red blood cells. The red blood cells contain a pigment called haemoglobin, each molecule of which binds four oxygen molecules. Oxyhaemoglobin forms. The oxygen molecules are carried to individual cells in the body tissue where they are released.

image result for how many calories of energy will 20 grams of carbohydrates provide in one gram provides 4 calories

consuming the right balance of protein, carbohydrates and fat can you maintain a healthy weight and optimize your energy levels. protein and carbohydrates both contain 4 calories per gram, while fat provides 9 calories per gram.