Most animals consume other organisms to survive. Consumers (heterotrophs) are divided into three types, primary, secondary, and tertiary, based on their place in the food chain.

Kinetic energy is the energy posessed by a moving object. Potential energy is stored energy in a stationary object based on its location, position, shape, or state.

Found in both animal sources (meat, fish, eggs, cheese) and vegetables (beans, nuts, some grains), proteins are important for the body's maintenance, growth, and repair.

The small intestine is where most digestion takes place. As food travels along the small intestine it gets broken down completely by enzymes secreted from the walls. These enzymes are produced in the small intestine as well as in the pancreas and liver. After the enzymes break down the food, the resulting substances are then absorbed into the blood via capillaries in the small intestine walls.

Temperatures again increase with altitude in the thermosphere which is the hottest (4,530 °F / 2,500 °C) atmospheric layer due to direct exposure to the Sun's radiation. However, the gas in this layer is highly diluted so even though the atoms of gas may be very high in temperature, there are too few of them to effectively transfer much heat.