Amino Acids
Amino Acids
Amino acids are the building blocks of proteins. Living things are able to produce vast types of proteins out of only twenty different amino acids. Nearly half the number of amino acids needed to make proteins cannot be made by the body and must be obtained from food.
Proteins are essential to all living things, and for animals especially they perform many critical tasks. Without proteins, there would be no life,
and without amino acids, there would be no proteins. While there are many types of amino acids (some two hundred and fifty have been found in plants and fungi), for humans there are only twenty that are found in proteins. Out of these twenty amino acids, the body is able to manufacture the thousands of different proteins that it needs for growth and repair. The body uses various combinations of the twenty acids to make proteins in much the same way the twenty-five letters of the alphabet are used in various combinations to make different words. Proteins are therefore made of amino acids linked or bonded together in different chainlike combinations. The properties of an individual protein are determined by the sequence or order in which the amino acids are linked together. Therefore, different proteins have different sequences of amino acids.
While most bacteria and plants can make all the amino acids they need, the cells of humans and most other animals are not able to manufacture all of the biologically important amino acids. It is estimated that of the twenty amino acids needed by humans, only ten can be made by the human body. The other ten must be obtained from the food the organism eats. In fact, the human body really gets all of its essential amino acids from the food it consumes since it is only able to make some amino acids by converting the others that it gets from outside its food. Therefore, unless the body obtains certain "essential" amino acids from its protein food source, it does not have the building blocks to make any other amino acids. In such a case, the body's protein-making ability would break down. Nutritionists have determined that all of these essential amino acids can be obtained from meats, eggs, milk, cheese and other foods derived from animals.