So following our enzymeatic reaction these coenzymes, known as Co substrates usually change themselves. And to actually regenerate that Co substrate we have to undergo some other type of reaction that usually involves energy. Now, one example of a prosthetic group, basically a Co enzyme that tightly binds to our enzyme is the heme group. And we'll talk more about the heme group when we discuss hemoglobin. Hemoglobin is basically a biomolecule or protein that binds oxygen and carries oxygen to the different tissues found in our body. Now an example of a loosely health group that we're going to discuss is our coenzyme A which is basically a molecule that is involved in cellular respiration.