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.
Substrate-level phosphorylation is a type of chemical re action that results in the formation of adenosine triphosphate (ATP) by the direct trans fer of a phosphate group to adenosine diphosphate (ADP) from a reactive intermediate. substrate. Molecule that undergoes a change in a re action catalyzed by an enzyme.) ~ s bind to the active site of an enzyme and convert the ~ s into products. 5) The three dimensional shape of the enzyme and of the active site determines its activity. 6) The way in which a ~ fits into an active site is often referred to as the lock and key model.