ABSTRACT

Animals are mainly herbivores. Certain species, such as cows, can

digest carbohydrate cellulose and change it into nutrients. Humans

are mainly dependent on an intake of carbohydrates in the form of

sugar and starch, but also need protein, carbohydrate, vitamins,

minerals, etc. Humans and animals depend entirely on air for respiration. Oxygen

enriches the blood and makes the body capable of burning food in an

exothermic reaction releasing heat, approximately 80-150 W for an

adult human being, depending upon the level of activity.