Regulation of iron absorption and transport. Iron for use in synthesis of heme, iron-sulfur centers and other non-heme iron proteins is obtained from the diet and via release of recycled iron from macrophages of the reticuloendothelial system that ingest old and damaged erythrocytes (red blood cells).
Four-stroke oil is more like the oil used in cars but both 2-stroke and 4-stroke oil serve the same purpose - to keep the engine lubricated. Four-stroke dirt bike oil comes in a variety of weights like 10w-40, 20w-50 and so on. It is not mixed with gas.
Not all motorcycle oil is the same. Mobil 1 10W-40 4-Cycle Motorcycle Oil is a full-synthetic, high-performance engine oil formulated specifically to meet the demanding needs of motorcycle engines. Mobil 1 Racing 4T 10W-40 motorcycle oil is designed primarily for on-road, high-performance, 4-cycle sport bikes.