How is Food like Fuel?

Question

How is the process by which your body extracts energy from food similiar to how a car's engine extracts energy from fuel? How is it different?

Answer 1

Food is like fuel in that it is the source of energy in every function of every cell in the body.

This fuel from food generally comes from glucose (sugar) manufactured mostly from the carbohydrates we eat; from amino acids, manufactured from proteins; and fatty acids, from the fats that we eat.

Certain body functions require certain forms of fuel (energy) and to provide this, we burn the glucose, the amino acids and fatty acids. actually the last two enter into cellular processes necessary to sustain life.

It is somewhat different from fuel that the engine uses because all the energy from fuel comes from the heat that it generates, whereas food energy is generated from the calories burned as a result: 4 calories each per gram of protein or carbohydrate, and 9 calories per gram of fat.

Answer 2

You cannot destroy energy, you can only change it. Food and petrol have chemical energy. Your body, and a car engine, convert the chemical energy to heat energy, and mechanical energy. This energy is then used to move you and the car. When you and the car move, you apply force and heat to the outside world in the form of energy.

Answer 3

I'd suggest that you read your book and think a little bit about what you've learned there, and what you know about how a car engine burns fuel.