Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?a. the citric acid cycleb. the electron transport chainc. glycolysisd. reduction of pyruvate to lactate

Verified step by step guidance

1. Identify the main metabolic pathways involved in the breakdown of glucose: glycolysis, citric acid cycle, and electron transport chain.
2. Understand that glycolysis is the initial step in both fermentation and cellular respiration, where glucose is broken down into pyruvate.
3. Recognize that the citric acid cycle and electron transport chain are parts of cellular respiration, not fermentation.
4. Note that fermentation involves the reduction of pyruvate to lactate or ethanol, but this is not a shared step with cellular respiration.
5. Conclude that glycolysis is the only pathway common to both fermentation and cellular respiration.

Key Concepts

Glycolysis

Glycolysis is the metabolic pathway that breaks down glucose into pyruvate, producing a small amount of ATP and NADH in the process. It occurs in the cytoplasm of cells and is the first step in both fermentation and cellular respiration, making it a common pathway for energy extraction from glucose.

Fermentation

Fermentation is an anaerobic process that allows cells to generate energy without oxygen. It follows glycolysis when oxygen is scarce, converting pyruvate into various end products, such as lactate or ethanol, while regenerating NAD+ to sustain glycolysis and ATP production.

Cellular Respiration

Cellular respiration is an aerobic process that fully oxidizes glucose to produce ATP, carbon dioxide, and water. It includes glycolysis, the citric acid cycle, and the electron transport chain, allowing for a more efficient energy yield compared to fermentation, which only partially oxidizes glucose.