Living things carry out almost all the life processes
or activities. These life processes include
digestion, respiration, circulation, excretion, locomotion,
immunity, coordination, and synthesis. Non-living
things are incapable of carrying out at least one or more of
the life processes. The sum of the energy
used in all the life processes represents the metabolism
of the organism.
The ability to carry on the life processes allow a living
thing to maintain dynamic equilibrium or homeostasis
with their surroundings. Homeostasis is a state of
balance or steady state between a living thing and its
environment. Homeostasis in an organism is constantly threatened.
Failure to respond effectively to a failure of homeostasis can result in disease or death.