IIa's use more fat than I's and IIb's - negligible usage. FFA uptake by muscles from the blood is closely related to blood concentrations. At least half the fat carried by the blood is removed by the muscle during one 'sweep of the circulation'. FFA mobilisation increases with exercise and is hormonally regulated. Glucose concentrations in the blood therefore decrease FFA release.
Transport is related to available albumin and blood perfusion through the adipose tissue.
Three high-affinity binding sites on each albumin molecule. FFA is carried into the cell and carnitine transports it once inside. They arise from partial oxidation of FFA in the liver and can be used by most aerobic tissues. The average adult in the Western World consumes twice the RDI of proteins. Proportion of protein from animal sources has increased at the cost of protein from plants.