Ch. 16: Energy expenditure: body size, locomotion, and reproduction
-Animals derive chemical energy from food, which they use to perform work, maintain their structural
integrity, and ultimately reproduce.
-animals degrade large organic compounds to transfer some of their chemical energy to special “high-
energy” molecules, such as ATP
-these molecules are subsequently used to drive endergonic (energy- requiring) reactions.
-Thus, animals eventually use the chemical energy of food to produce electrical, ionic, and osmotic
gradients, synthesize metabolites, and carry out work via muscle contraction
-animals that are more effective at capturing and using the energy resources available in their
environment are better able to compete against members of their own and other species, and are
therefore more fit in an evolutionary sense
The concept of energy metabolism
-metabolism: is the sum total of all the chemical reactions occurring in an organism
-because the rate of a chemical reaction increases with temperature, the metabolic activity of an animal
is closely linked to its body temp.