Cells use blank to get energy only when carbohydrates are not available

The correct answer would be lipids.

Explanation:

Glucose degradation release energy in the cell in the form of ATP. however, when carbohydrates are not available cells initiates degradation of lipids allows cells to get the necessary energy for their survival.

Degradation of lipids takes place in the mitochondria, according to a set of chemical reactions grouped under the beta-oxidation of fatty acids. Lipid degradation release energy twice of the carbohydrate degradation by almost 9 calories.

Thus, the correct answer would be lipids.

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