Final answer:
The statement regarding the exclusive use of intermediates in glycolysis and the Kreb's cycle for energy production is false. These pathways also contribute to the synthesis of biomolecules such as amino acids and lipids.
Step-by-step explanation:
The statement that intermediates in glycolysis and the Kreb's cycle are used exclusively for energy production is false. While these metabolic pathways do produce energy in the form of ATP, they also serve important anabolic functions. Intermediates from both glycolysis and the Kreb's cycle, also known as the citric acid cycle or tricarboxylic acid cycle, are utilized in the synthesis of various biomolecules. Examples include the production of nonessential amino acids, nucleic acids, lipids such as cholesterol and triglycerides, and certain metabolic intermediates used by cells for other biosynthetic pathways.
The end products of glycolysis, pyruvate molecules, can enter the Kreb's cycle if oxygen is present, but they can also be converted into lactate or ethanol through fermentation in the absence of oxygen. Additionally, the net production of ATP directly from glycolysis is impacted by the need to transport NADH into the mitochondria. Furthermore, the Kreb's cycle generates high-energy molecules such as NADH and FADH2, which are critical for the electron transport chain in ATP production, but the intermediates of the cycle are also essential for the biosynthesis of numerous other compounds.