FAT. Of all the major macromolecules, fat has the highest energy potential given that it provides 9 calories per gram. Protein and carbohydrates provide 4 calories per gram each. However, it is not very efficient for the body to store, manage, and convert fat into energy, this is where carbohydrates come in. read more
Proteins, and in particular ATP synthase. Humans make ATP both in the cytosol (via glycolysis) and in mitochondria (via several processes in a series: conversion of pyruvate into acetyl CoA, the tricarboxlyic acid cycle, the electron transport system, and finally chemiosmosis). read more