Food provides calories needed by the body for energy. However, the body must use energy between meals when food is not consumed. What is the most likely response of the body when more energy is used than the calories consumed provide?

Choice 1

to transform stored proteins into carbohydrates for energy

Choice 2

to increase blood flow to the limbs for energy production

Choice 3

to release energy from lipids stored throughout the body

Choice 4

to contract muscles to create heat energy for the body

The correct answer is: Choice 3-to release energy from lipids stored throughout the body.

The first source of energy in the human body are carbohydrates which are hydrolyzed to their monomeric units such as glucose (glucose is then used for ATP production). Since carbohydrate stores are very small, they are used very quickly.

The second source of energy are fats. The human body will produce Acetyl Co A from the fatty acids by the process of Beta-Oxidation. Acetyl Co A then enters the Krebs Cycle (mitochondria) to produce ATP.

The last source of energy are proteins.