If an animal eats only meat, what would be its primary source of glucose?

• A. Direct absorption of glucose from meat
• B. Gluconeogenesis from amino acids
• C. Photosynthesis in muscle cells
• D. Fermentation of dietary fiber

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the dietary habits of the animal. An animal that eats only meat is classified as a carnivore. Carnivores primarily consume proteins and fats, which are abundant in meat, rather than carbohydrates like glucose.
2. Step 2: Recall that glucose is a vital energy source for cells. Since meat does not contain significant amounts of glucose, the animal must produce glucose internally through metabolic processes.
3. Step 3: Learn about gluconeogenesis. This is the metabolic pathway by which glucose is synthesized from non-carbohydrate precursors, such as amino acids derived from proteins in the meat. This process occurs primarily in the liver and kidneys.
4. Step 4: Eliminate incorrect options. Direct absorption of glucose from meat is not possible because meat lacks significant glucose content. Photosynthesis does not occur in animals, as it is a process exclusive to plants and some microorganisms. Fermentation of dietary fiber is irrelevant because carnivores do not consume fiber-rich diets.
5. Step 5: Conclude that the primary source of glucose for a carnivorous animal is gluconeogenesis from amino acids, which are broken down from the proteins in the meat it consumes.