Cofactors are non-protein chemical compounds that assist enzymes in catalyzing biochemical reactions. They can be metal ions, like zinc or magnesium, or organic molecules known as coenzymes, such as NAD+ or coenzyme A. Cofactors help enzymes achieve their active form, enabling them to interact with substrates effectively. These essential components can be classified as either tightly bound or loosely associated with the enzyme. Tightly bound cofactors are often called prosthetic groups, while loosely associated ones can be removed without affecting the enzyme's structure. Overall, cofactors play a crucial role in enhancing enzyme activity and facilitating metabolic processes.