A metabolic pathway is best described as a the set of molecular reactions in which enzymes make or break down sugars.
Explanation: A metabolic pathway refers to a series of chemical reactions that occur within a cell, facilitated by enzymes. These pathways are crucial because they enable the conversion of substrates (like sugars) into products through a series of steps. Each step in a metabolic pathway is typically catalyzed by a specific enzyme, which speeds up the chemical reactions and ensures that the cell’s metabolism functions efficiently. This contrasts with option b, which incorrectly states that pathways do not involve enzymes, and option c, which does not provide a complete definition. Therefore, the first statement accurately encapsulates the essence of metabolic pathways.