Proteins

• Proteins, like all macromolecules, are composed of smaller units that combine and connect together to form one larger molecule. Amino acids, which are smaller, simpler molecules, connect end to end to form proteins. Because there are 20 different amino acids that all life uses and requires, there are a number of possible combinations, and thus, a large number of possible proteins. Each protein has its own particular function, ranging from attacking antigens in the blood, to regulating metabolism, to digesting particles of food. Proteins are involved in most life processes.