In a scenario where a cell requires increased protein synthesis, which molecule would be more directly utilized in the mitochondria, and why?

• A. FADH2, because it is involved in electron transport chain.
• B. NADH, because it provides reducing power for synthesis reactions.
• C. ATP, because it has a higher energy value than GTP.
• D. GTP, because it is directly used in mitochondrial protein synthesis.

Answer: (D)