Protein: The Many Wonderous Forms of Amino Acids

Macronutrient is the name given to fats, carbohydrates and proteins, they are called this because they are the things the body needs in larger quantities. Micronutrients are vitamins and minerals and other things that the body needs, although in smaller quantities. As a fuel, proteins and carbohydrates provide 4 kcal (17kJ) per gram while fats provide 9 kcal (37 kJ) per gram.

 

Over 10,000 different proteins make up our bodies, researchers have proposed up to several billion different proteins may be necessary for our functioning. Excluding water, 75% of our body is made up of proteins: our hair, our organs and even within our blood – haemoglobin is a type of protein and the antibodies that are part of our immune system are proteins too.

 

Proteins are made from amino acids. There are at least 20 different types of amino acid and they come together in different ways to create all the proteins in our bodies. Because we don’t store amino acids, our bodies make them in two different ways: either from scratch, or by modifying others. Nine amino acids are called essential —histidine, isoleucine, leucine, lysine, methionine, phenylalanine, threonine, tryptophan, and valine (others are conditionally essential - they are needed when the body is going through changes, for instance pregnancy or fighting an illness). These must be consumed because the body can not modify others to make them. Animal proteins contain all of the essential amino acids, as do edamame, peas, buckwheat, mycoprotein, quinoa and tofu. Rice and beans together makes a complete protein as most beans are low in methionine and high in lysine, while both brown and white rice is low in lysine and high in methionine.

 


 

 

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