Answer:
The correct answer is B. Proteins.
Proteins are especially important because they are involved in a variety of processes, such as cell signaling, immune response, and enzyme activity.
Explanation:
Proteins are large biomolecules formed by different types of basic units called amino acids, which are held together by chemical bonds. The human body uses proteins to move, grow, repair tissues and even to defend against disease-causing agents (immune response). The cell surface houses a large number of proteins responsible for the recognition of chemical signals (cell signaling) of many different types. There are hormonal receptors, neurotransmitters, antibodies, viruses, bacteria among others. Antibodies are proteins that help animals fight the invasion of viruses and batteries. Proteins known as enzymes direct the chemical reactions that occur in cells, so they are essential.
