Passive vs. Active Cellular Processes

Steps:

• Respiration generates ATP to power active biological processes requiring energy input.
• Evaluate each option: active processes use ATP, while passive ones rely on natural gradients without energy.
• Protein synthesis (A) and mitosis (D) are active, needing ATP for bonding and division.
• Diffusion (B) is passive; thermoregulation (C) requires metabolic ATP for heat generation.

Why B is correct:

• Diffusion moves oxygen down its concentration gradient into blood via passive transport, requiring no ATP as defined by Fick's law of diffusion.

Why the others are wrong:

• A: Converting amino acids to proteins uses ATP for peptide bond formation in translation.
• C: Maintaining 37°C body temperature demands ATP from respiration to produce metabolic heat.
• D: Mitosis requires ATP for chromosome movement and spindle assembly during cell division.

Final answer: B