The construction of proteins actually occurs from the free amino acids available to the body. The body has to break down all protein (if it can) into its constituent parts, the amino acids, before the material can be utilized. Protein is a collection of amino acids.
The best, cleanest sources of proteins are green vegetables, seeds (hemp, flax, sesame, poppy, sunflower, chia, etc.) and superfoods.
For clarity, superfoods are plant foods with extraordinary properties. Usually they contain all essential amino acids, high levels of minerals, and a wide array of unique, even rare, nutrients.
The World Health Organization has established a minimum daily requirement of 32 grams of protein for a 150 pound (68 kg) male.
Three tablespoon of spirulina contains about ten grams of protein.
Dr. C. Samuel West describes in his book The Golden Seven Plus One that the primary cause of disease is undigested protein trapped in the intercellular fluid between the cells.