Question

When a muscle moves, a phosphate is removed from ATP. Breaking a bond in ATP allows the chemical energy stored in the bond to disperse in a muscle cell in the forms of mechanical energy and heat energy. How does the second law of thermodynamics apply to this process?

Answer 1

The second law of thermodynamics applies to the process of muscle movement and ATP hydrolysis because it states that entropy increases and energy transformations are not completely efficient. In muscle cells, energy from ATP is used for contraction, while some is lost as heat, aligning with the law's assertion that not all energy can be transformed into useful work.

Step-by-step explanation:

When a muscle moves, a phosphate is removed from ATP (adenosine triphosphate), and energy is released. This energy disperses in the muscle cell, partly as mechanical energy and partly as heat. The second law of thermodynamics applies to this process because it explains how energy transformations are never completely efficient.

The second law of thermodynamics states that entropy, or disorder, always increases in the universe. This law also implies that in every energy transfer, some energy is lost in a form that is unusable, usually as heat. This is seen in the muscle cell where the energy not used for mechanical work (e.g., muscle contraction) is often lost as heat, contributing to the increased entropy in the environment.

The process of ATP hydrolysis during muscle contraction illustrates the application of the second law of thermodynamics in biological systems. Free energy released from ATP is used to power the muscle contraction, but some of it is inevitably lost as heat, making the process less than a hundred percent efficient and hence increasing the overall disorder of the system.

Answer 2

Some of the energy released by ATP hydrolysis is used in muscle movement while the rest is lost as heat.

Explanation:

According to the second law of thermodynamics, when energy is transformed from one form to another, some energy is used to perform work while the rest is lost as heat to the surroundings. The energy heat energy lost to the surroundings cannot be used to perform functions.

According to the given information, the chemical energy released from the breakdown of ATP is converted into mechanical energy during the movement of a muscle. However, some of the energy released from ATP is lost as thermal energy and is not available to serve in the movement of muscles. This loss of part of the energy as heat during muscle movement explains that the process follows the second law of thermodynamics.