Examples of antioxidants include vitamins C and E, selenium, and carotenoids, such as beta-carotene, lycopene, lutein, and zeaxanthin. This fact sheet provides basic information about antioxidants, summarizes what the science says about antioxidants and health, and suggests sources for additional information. Key Points Vegetables and fruits are rich sources of antioxidants.
Proteins, among the most complex of all organic compounds, are composed of amino acids (see Figure 2-4), which contain carbon, hydrogen, oxygen, and nitrogen atoms. Certain amino acids also have sulfur atoms, phosphorus, or other trace elements such as iron or copper.
Proteins are made of amino acids. Carbohydrates, DNA and fat are not made of amino acids. Protein is the building block of life. Most of the structures (e.g. feathers, hair,â¦ the external skeleton of insects, the sting of a bee and a jelly fish, etc.) found in nature are made of proteins. Even single celled organisms must rely on proteins.