Protein Functions

Consumed proteins are digested into amino acids, and these amino acids join other amino acids produced by the body to constitute the amino acid pool. The tissues take the amino acids from this pool to synthesize the specific proteins the body needs (muscle, hair, nails, hormones, enzymes, and so on). This amino acid pool is also available for use as energy (via a deamination process) to be burned if other fuels (carbohydrate and fat) cannot satisfy energy needs.

The major functions of protein include the following:

1. Protein provides a source of carbon for energy-yielding reactions. Certain amino acids can be converted to glucose and metabolized to provide ATP, while others can be stored as fat that can subsequently be catabolized to provide ATP.
2. Protein is a critical compound in controlling fluid volume and osmolarity in the blood and body tissues. This function is a major controlling factor in maintaining water balance.
3. Proteins are amphoteric, with the capacity to buffer both acid and alkaline environments to maintain an optimal blood pH.
4. Antibodies are protein-based substances critical for maintaining health.
5. Proteins form enzymes that are involved in digestive and other cellular processes that create needed chemical end products.
6. Proteins are a critical component of body tissues, including the organs (heart, liver, pancreas, and so on), muscles, and bones.
7. Proteins are “smart” transporters of substances in the blood, moving substances to the correct receptor sites. For instance, transferrin is the protein transporter for iron.
8. Proteins are synthesized into specific hormones (such as insulin) and neurotransmitters (such as serotonin) that control body function.