What is the primary source of glucose needed for cellular respiration in humans?

• A. Dietary carbohydrates
• B. Atmospheric oxygen
• C. Stored proteins
• D. Fatty acids

Answer: (A)

Verified step by step guidance

1. Understand that cellular respiration is the process by which cells convert glucose and oxygen into energy, carbon dioxide, and water.
2. Recognize that glucose is a simple sugar that serves as a primary energy source for cells during cellular respiration.
3. Identify the sources of glucose in the human body: dietary carbohydrates, stored glycogen, and gluconeogenesis.
4. Focus on dietary carbohydrates as the primary source of glucose. When consumed, carbohydrates are broken down into glucose during digestion.
5. Eliminate the other options: Atmospheric oxygen is not a source of glucose, stored proteins are primarily used for building and repair, and fatty acids are used in beta-oxidation, not directly for glucose production.