<span>Food energy comes mainly from carbohydrates, protein, and fat from the food humans eat. Food energy usually comes from carbohydrates and fats rather than proteins. Energy is usually consumed because of various metabolic and enzymatic processes; and any excess in energy is stored as fat (in adipose tissue) and glycogen (in the liver and in muscles). Food energy that are not used are lost as heat<span>.
</span><span><em>Producing heat is not actually a byproduct of the inefficiency of metabolism. Heat is actually used to maintain core body temperature to make sure that thermosensitive enzymatic processes are not inhibited.</em></span></span>
To obtain the energy from food and store it as either fat or glycogen a series of metabolic chemical reactions take place in the cells of the organism.
During this chemical reaction, a large amount of heat is also produced that is either used to maintain the core temperature of the body which is an essential requirement or is lost through the skin to the environment.
This is the reason why the energy conversion is not 100% efficient because heat losses are always there.
It is estimated that around 75% of the energy that is obtained from food is lost as heat and only 25% gets stored.
Areoles are the tissue that make up most of the stem of cacti. These are specialized structure that give birth to flowers and are often tubular and multipetaled. This structure enables the plant to survive in the harsh conditions of the desert and help them absorb water from the soil efficiently.
