1 Animal Energetics

Why do animals need energy?

In an isolated system, change occurs in the direction of greater disorder so animals need energy to maintain/increase the stable organization of their bodies as they are open systems

What is high grade energy?

Energy that can be used to carry out physiological work

• Chemical

• Electrical

• Mechanical

What is low grade energy?

Energy that cannot perform physiological work or increase organization of body systems

• Heat

Why can’t animals recycle energy already in their bodies?

Because transformations of high grade energy to perform work are inefficient. Some of the energy is always lost as heat

In what way is energy transformed?

High grade energy is transformed to perform work with some being lost as heat (low grade). Always high grade to low grade

Absorbed energy =

ingested energy - fecal energy

What is biosynthesis?

The synthesis of body constituents

What is maintenance?

All the processes that maintain the integrity of the body

What is external work?

The application of mechanical forces to objects outside the body

What is metabolic rate>

The rate at which an animal consumes energy

What is basal metabolic rate?

Applies to homeotherms and is the metabolic rate when the animal is in its thermoneutral zone, fasting, and resting

What is standard metabolic rate?

Applies to poikilotherms and is metabolic rate when the animal is fasting and resting