Organic Chemistry:
A
molecule is said to be
saturated if it has no double or
triple bonds. Since the term is usually used to refer to
hydrocarbons, it means that it's saturated with
hydrogen. For example,
saturated fat.
Enzymology:
Populations of enzymes are saturated when all the individual enzyme molecules potentially have a bound substrate. This makes the step of converting the enzyme-substrate complex to product rate limiting.