Figure 1 - The potential parts of a typical enzyme. Not every enzyme will have a prosthetic group or a coenzyme. Each enzyme is unique. Many of the vitamins are coenzymes. Figure 2 - An enzymatic reaction with two substrates and one product.
Enzymes are efficient and specific The efficiency of enzymes is extremely high.
Most also have a high degree of specificity binding a specific molecule and converting it to a specific product. Enzyme and substrate fit into each other like a lock into a key. Visualizing enzymatic catalysis To understand how enzymes catalyze reactions, you first have to get you head around the idea of activation energy. Many chemical reactions require an initial amount of energy be added to get them to proceed forward. Even thermodynamically favorable reactions need a little boost of energy.