To hear audio pronunciation of this topic, purchase a subscription or log in.

[L. fractio, act of breaking]

1. In biological chemistry, the separable part of a substance such as blood or plasma.
2. The ratio of a component to the total, e.g., the substance fraction of carboxyhemoglobin (relative to the total hemoglobin).

There's more to see -- the rest of this topic is available only to subscribers.