You might see the word alloy described as a mixture of metals, but that's a little bit misleading because some alloys contain only one metal and it's mixed in with other substances that are nonmetals (cast iron, for example, is an alloy made of just one metal, iron, mixed with one nonmetal, carbon).
Energy substrates in the human body are either carbohydrates, fat or proteins. Protein degradation yields amino acid residues which can be converted to carbohydrates and used in energy production. Carbohydrates (sugars) and amino acids from proteins give approximately 4 kcal/gram dry weight when burned in the body.
Several energy sources or substrates are available which can be used to power the production of ATP. One of these substrates, like existing ATP, is stored inside the cell and is called creatine phosphate. Creatine Phosphate. Creatine phosphate is readily available to the cells and rapidly produces ATP.ogether ATP and creatine phosphate are called the high-energy phosphogens (1). Fat. The other substrates that can the body can use to produce ATP include fat, carbohydrate and protein. Fat is stored predominantly as adipose tissue throughout the body and is a substantial energy reservoir.