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.
  Respiration is oxidation of foods, a catabolic process in living cells which liberate energy for this purpose of liberation of energy the compond used or oxidised is cal â¦ led respiratory substrate. substrate molecule hydrogen bonds to the active site on an enzyme and causes it to distort. The distortion stresses a bond in the substrate, causing it to break into two pro â¦ duct molecules. These are released by the enzyme and drift away.