<img src="https://d5nxst8fruw4z.cloudfront.net/atrk.gif?account=iA1Pi1a8Dy00ym" style="display:none" height="1" width="1" alt="" />
Skip Navigation
Say Thanks header

Protein Classification

Introduces the four levels of structure for polypeptides.

Atoms Practice
Practice Protein Classification
Practice Now
Please Pass the Beans

Please Pass the Beans

Credit: Peggy Greb
Source: http://en.wikipedia.org/wiki/File:Soy-whey-protein-diet.jpg
License: CC BY-NC 3.0

A vegetarian diet is considered by many people to be healthier than one containing meat, eggs, and dairy products. A major source of disagreement comes when looking at the specifics of a vegetarian diet. One concern has to do with the amino acid supply to the body, from which proteins are made. Will a specific vegetarian diet provide the necessary materials to give the body the tools needed for proper development?

News You Can Use

  • Proteins are polymers composed of amino acids and serve several important functions in the body. Several muscle tissues (such as cardiac muscle and skeletal muscle) contain large amounts of protein. Body protein cannot be obtained directly from the diet since any dietary protein consumed is digested in the small intestine. The amino acids in the diet, provided largely by the dietary protein, serve as the source of the building blocks for the various proteins in the body.
  • Most individuals will consume a certain amount of meat, dairy products, and eggs in their diet. These foods will provide all the essential amino acids in an adequate amount. Overconsumption can lead to high cholesterol (due to the fats in the meat), kidney problems (although the data are mixed as far as this problem is concerned) and gout (caused by high uric acid levels).
  • Vegetarians have a greater challenge to obtain an adequate amino acid intake. Generally, a mix of several different plant proteins may be sufficient, but care must be taken to achieve the proper balance of the different amino acids in the diet. One plant that is said to have a complete supply of the essential amino acids is quinoa, a grain-like material.
  • Credit: net_efekt
    Source: http://www.flickr.com/photos/wheatfields/3018416303/
    License: CC BY-NC 3.0

    Quinoa is a relatively new addition to the American diet. However, it has gained popularity very quickly due to its unique nutritional profile [Figure2]


  • Amino acid supplements are widely used by athletes and body-builders. These materials are widely marketed in a variety of stores and on the Internet. In general, each amino acid is packaged separately, so the consumer can tailor their purchases to meet their individual dietary goals. There is little evidence to suggest any long-term benefit from taking these supplements and some data to indicate that some specific amino acids can contribute to health problems.
  • Watch the video at the link below to learn about amino acids in the diet: https://www.youtube.com/watch?v=391TXlzbWo8

Show What You Know

Use the links below to learn more about amino acids, proteins, and proper diet. Then answer the questions below.

  1. What are essential amino acids?
  2. What are conditionally essential amino acids?
  3. What are recommended portions of meat for a good protein supply?
  4. What are some good non-meat sources of protein?
  5. Does the use of amino acids supplements enhance athletic performance?

Image Attributions

  1. [1]^ Credit: Peggy Greb; Source: http://en.wikipedia.org/wiki/File:Soy-whey-protein-diet.jpg; License: CC BY-NC 3.0
  2. [2]^ Credit: net_efekt; Source: http://www.flickr.com/photos/wheatfields/3018416303/; License: CC BY-NC 3.0


Please wait...
Please wait...

Original text