Which human cell type typically contains the greatest number of mitochondria to meet its high energy demand?

• A. Adipocyte (fat cell)
• B. Cardiac muscle cell (cardiomyocyte)
• C. Red blood cell (erythrocyte)
• D. Keratinocyte (epidermal skin cell)

Answer: (B)

Verified step by step guidance

1. Understand the role of mitochondria: Mitochondria are the organelles responsible for producing ATP, the energy currency of the cell, through cellular respiration.
2. Consider the energy demands of each cell type: Cells that require a lot of energy to perform their functions typically contain more mitochondria.
3. Analyze each option: Adipocytes store fat and have moderate energy needs; red blood cells lack mitochondria because they rely on glycolysis; keratinocytes are skin cells with relatively low energy demand.
4. Focus on cardiac muscle cells: These cells contract continuously to pump blood, requiring a constant and high supply of ATP, so they contain a large number of mitochondria.
5. Conclude that the cell type with the greatest number of mitochondria is the cardiac muscle cell (cardiomyocyte) due to its high and continuous energy demand.