ABSTRACT
All living organisms must perform work to stay alive, to grow, and to reproduce themselves. Liv ing organisms are able to harness energy from various sources and to channel it into different types of biological work. Organisms carry out a remarkable variety of energy transductions, i.e., conversion of one form of energy to another; e.g., animals use chemical energy in the form of food (fuels) to synthesize complex molecules from simple precursors, producing macromolecules with highly ordered structures. They also convert the chemical energy of various fuels into concentra tion gradients and electrical gradients, motion, heat, and even light (as in fireflies). Photosynthetic organisms and higher plants transduce the sun’s (light) energy into all other forms of energy.
