If a person were fasting and hadn’t eaten for several days in a row, which source of energy would the body use as a last resort?
lipids
protein
glycogen
lactic acid

Protein

Explanation:

Energy is the fuel that is used by the body to perform various tasks of the body. There are various sources of energy present inside our body. These sources are carbohydrates, fats, proteins and alcohol.

Firstly the carbohydrate is used as a fuel by the body to perform various tasks. It is the main fuel used by the brain and body.

Fats are used after carbohydrates and the last reported source of energy is protein. it builds up the muscle tissue.

the sugar-phosphate backbone forms the structural framework of nucleic acids, including dna and rna. this backbone is composed of alternating sugar and phosphate groups, and defines directionality of the molecule.