Gold Member Badge


  • You're all caught up!

Six Primary Functions of Proteins

author image Elle Paula
Elle Paula has a Bachelor of Science in nutrition from Framingham State College and a certificate in holistic nutrition from the American College of Healthcare Sciences. She is also a licensed aesthetician with advanced training in skincare and makeup. She plans to continue on with her education, complete a master's degree program in nutrition and, ultimately, become a registered dietitian.
Six Primary Functions of Proteins
Proteins allow your joints to bend so you can run. Photo Credit: gbh007/iStock/Getty Images

Proteins are compounds in your body made up of amino acids, which contain carbon, oxygen, hydrogen and nitrogen. While protein can provide your body with energy because it has 4 calories per gram, this is not one of its primary functions. The proteins in your body, which come from the foods you eat, play six primary physiological roles.

Video of the Day


Without proteins, you could not move, bend or even stand up straight. Proteins support your connective tissues, which are found in your tendons, ligaments and bones. These tissues connect your joints and allow movement. Other proteins, called actin and myosin, permit your muscles to contract. This allows you to run, sit and lie down.

Immune Response

Antibodies are substances that help fight off potential hazards to your body, like bacteria or viruses. When exposed to a pathogen, your body creates antibodies, which are made from protein, to keep you safe. Your immune system can produce up to 2,000 antibodies per second, according to “Nutrition and You” by Joan Salge Blake.


Some proteins in your body help transport various substances throughout your blood. A protein called hemoglobin, which is found in your red blood cells, brings oxygen to your tissues and carbon dioxide to your lungs. Other proteins bring vitamin A to your liver and eventually to your cells.

Other transport proteins are found in cell membranes. These proteins allow sodium and potassium to move in and out of your cells.

Acid-Base Balance

Proteins also serve as buffers, helping maintain the pH of a solution. When your blood becomes too acidic, protein side chains pick up excess hydrogen ions to increase the pH of your blood. If your blood becomes too basic, or alkaline, other protein side chains donate hydrogen ions to decrease the pH.

Fluid Balance

Your body contains approximately 60 percent water, making it the most abundant substance in your body. For you to stay healthy, this water must disperse properly throughout your body, and proteins help do this. Proteins attract water, so they can pull fluid into capillaries and prevent it from accumulating in your body tissues. Without proteins, your body tissues would become bloated, leading to generalized swelling called edema.

Chemical Reactions

Enzymes are substances that speed up chemical reactions. Without enzymes, the chemical reactions in your body would occur so slowly, you would not be able to survive. Hormones are substances that direct a chemical reaction by turning enzymes on or off. Most enzymes and hormones in your body are proteins.

LiveStrong Calorie Tracker
Lose Weight. Feel Great! Change your life with MyPlate by LIVESTRONG.COM
  • Gain 2 pounds per week
  • Gain 1.5 pounds per week
  • Gain 1 pound per week
  • Gain 0.5 pound per week
  • Maintain my current weight
  • Lose 0.5 pound per week
  • Lose 1 pound per week
  • Lose 1.5 pounds per week
  • Lose 2 pounds per week
  • Female
  • Male
ft. in.


Demand Media