The only food that provides all the nutrients that humans need is human milk," Hattner said. "Mother's milk is a complete food. We may add some solid foods to an infant's diet in the first year of life to provide more iron and other nutrients, but there is a little bit of everything in human milk.
Neon is an element because it is a pure atom
Three of the functions of proteins are as antibodies, as enzymes and as messengers. As antibodies, they protect the cells from diseases ie they fight diseases. As enzymes, they regulate the chemical reactions within cells, and thirdly they transmit signals as messengers such as hormones do in co-ordinating biological processes. Proteins are so diverse because of their unique 3-D structures which their polymers form from the 20 amino acids available as their building blocks.