Emergency Medical Technician (EMT) Intermediate Practice Exam

What process, in addition to the Krebs cycle, is involved in converting glucose into energy?

1. Fermentation

2. Glycolysis

3. Oxidative phosphorylation

4. Beta-oxidation

The correct answer is: Glycolysis

Glycolysis is the correct answer because it is the initial metabolic process that breaks down glucose into pyruvate, generating a small amount of energy in the form of ATP in the process. This occurs in the cytoplasm of cells and does not require oxygen, making it a crucial pathway for energy production, especially in anaerobic conditions. Following glycolysis, the pyruvate produced can then enter the Krebs cycle (also known as the citric acid cycle) for further oxidation, leading to more ATP production through oxidative phosphorylation. Fermentation is a process that may occur after glycolysis if oxygen is unavailable, converting pyruvate into lactic acid or ethanol, depending on the organism. While it does help in regeneration of NAD+ necessary for glycolysis to continue, it does not further break down glucose, nor does it directly convert it into energy in the same way glycolysis does. Oxidative phosphorylation is the stage of cellular respiration where the energy carriers generated from both glycolysis and the Krebs cycle are utilized in the mitochondria to produce ATP. While it is a crucial component of cellular respiration, it necessitates the presence of glucose being first processed through glycolysis and the Krebs cycle. Beta-oxidation refers to the metabolic process of breaking