Describe the role of enzymes in metabolism?

Answer 1

To put it simply, enzymes are proteins that catalyze or speed up the reaction of processes within cells. So when an enzyme attaches to a process, such as metabolism, it can speed up the process. Enzymes regulate those processes by either being "on" or "off", meaning that some energy source such as ATP transfers a phosphate to the enzyme, changing its shape and turning it "on", and allowing it to catalyze the reaction. A good example of this is oxidative phosphorylation, in which the transfer of electrons and protons across the cell membrane at the electron transfer chain site move into a mitochondria, increasing the concentration of protons inside it, and the protons move from this concentrated proton area to the less concentrated area outside the mitochondria through an enzyme called ATP synthetase. This transfer across the membrane creates energy inside the ATP synthetase, like a water-mill, and the synthetase changes ATP into ADP and phosphorylated water, and ADP back into ATP. This facilitates an energy cycle, and thus affects metabolism.