The ability to do work is called

• A. Energy
• B. Membrane structure
• C. Osmosis
• D. Ion channel

Answer: (A)

Energy is the capacity to do work. In biology, work means any activity that moves matter, changes a system, or drives a reaction. So the ability to do work is energy, the measure of what can be used to power processes like moving substances across membranes or powering muscle contraction. The other terms describe structures or processes (a membrane barrier, the movement of water by osmosis, or a protein that lets ions through) and don’t define the capacity to perform work themselves, though they are ways energy is used within cells. In cells, energy is often stored as ATP and released to power various tasks.