The second law of thermodynamics says every energy transfer:

1. No energy transfer is completely efficient, because some energy is lost in an unusable form. 2. That unusable form is typically heat, which spreads out. 3. Since all energy transfers result in the loss of some usable energy, every energy transfer or transformation increases the entropy of the universe. 4. Living things stay ordered locally, but the universe's total entropy still rises. _Source: OpenStax Biology for AP(R) Courses (CC BY 4.0), Ch 6 'Metabolism', sections 6.1-6.5_