WHAT ARE CALORIES?

A calorie is simply, a unit of energy or heat that is required to raise 1 gram of water by 10C. (18 degrees Fahrenheit). 1 calorie is actually equal to 4.184 joules (joules being the unit of energy mostly used in physics).
The calories listed in food are actually kilocalories (1 kilocalorie = 1000 calories). Most foods list their calories with capital – C to try and show that they are referring to food calories. So, when a banana is said to have 300 calories, it actually has 300,000 calories. So, the banana has enough potential energy to raise 300,000 grams of water (that is 300 liters of water) by 1 degrees Centigrade.

To stay alive, the body will require energy to drive its numerous processes. Many organs will also require energy to function, like the brain,
the heart, the kidneys and so on. Processes like digestion, cell regeneration and active transport will require energy.
(Active transport is the process by which cells uptake ions and other substances through their cells against the concentration gradient from low concentrations, to high concentrations. The cells will tend to have the same concentration, if not higher, as the blood in the capillaries next to them, so they will require extra energy to facilitate the uptake of ions and dissolved nutrients through the cell membranes).

This energy (ie calories) is derived from food.

The number of calories in food is actually the potential energy present in that food.
One gram of fats has 9 calories, while proteins and carbohydrates each have 4 calories per
gram.

The body will "burn" the calories in the food through metabolic processes, by which enzymes break the carbohydrates into glucose and other sugars, the fats into glycerol and fatty acids and the proteins into amino acids. These molecules are then transported through the
bloodstream to the cells, where they are either  absorbed for immediate use or are sent on to the final stage of metabolism, in which they are
reacted with oxygen to release their stored energy.

Live life, take care!!
This is Serenity!!!

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