by Kris Verburgh
Proteins are an important factor in aging. When we understand the role of proteins in the aging process, we can also figure out how we can slow it down—via our diet, among other things. Proteins consist of thousands of atoms. Proteins have different, specific shapes. It is the specific shape that determines the type of protein. The body contains more than 20,000 different kinds of proteins. Since proteins are clusters of atoms, and since atoms are minuscule in size, proteins are also very small. The average diameter of a protein is about 10 nanometers (a nanometer is one millionth of a millimeter).
Proteins have two functions: First, they are the building blocks of our cells. A cell contains millions of proteins that provide shape and structure to our cells. Just as wooden beams form the framework for a house, long rods of proteins form the specific shape of the cell. White blood cells can capture bacteria with their long, protruding arms because the arms contain a hinging framework of proteins that moves the arm of the white blood cell toward the bacteria. The cells that form our bronchia have long protrusions that wave back and forth to sweep up dust and mucus from the bronchia. The framework of these long protrusions is made up of proteins.
Second, proteins are also the workhorses of our cells. They perform almost all tasks in and around our cells: They break down substances such as drugs, alcohol, or food; they build up substances such as fats or hormones; they allow substances such as glucose or sodium to pass into and out of the cells; and they store or package other substances, like iron or vitamin B12. There is virtually nothing about our body that proteins are not involved in. Specific proteins in the cells of your stomach produce and secrete stomach acid. Other proteins located in the wall of nerve cells in your buttocks and back register pressure, which allows you to feel the chair in which you are sitting right now. Certain proteins in the cells of your eye register light, which allows you to read this book. Long protein strands in your muscles can shorten and contract them, so that you can turn over this page, but also dance, laugh, or walk. Proteins are the engines of life. The DNA in our cells contains the instructions for building proteins. Without proteins there is no life.
There is one more thing you need to know; namely, that proteins are made up of strands of amino acids. There are twenty types of amino acids in the human body (that can form proteins). Amino acids are small atom clusters that are always built according to a fixed plan. Amino acids are threaded like a pearl necklace to form a protein. This long strand of amino acids folds itself into a specific shape, such as a ball, a rod, or a hollow cylinder, forming a specific protein. This folding is possible because the atoms of which the strand is made are positively or negatively charged and can attract or repel one another.
The relationship between atoms, amino acids, and proteins can be pictured as follows. Just as there are various types of Lego blocks with different colors and sizes, there are also different atoms, for example hydrogen, oxygen, carbon, and so forth. Just as Lego blocks can build small basic structures, such as walls, windows, or roofs, atoms can build the twenty different amino acids. And just as these small basic Lego structures can build houses, amino acids can build proteins. A protein can consist of a few dozen of amino acids (a small house) or up to many thousands (a gigantic palace). Readers who want to learn more about proteins and amino acids can find more details at the end of the book, in the section “Additional Reading.”
Proteins, and therefore amino acids, are found primarily in meat. Meat consists mainly of muscle cells, which are full of proteins. Fish, eggs, and cheese also contain a lot of proteins; and the proteins we eat do not only come from animals —plants contain proteins as well. Rich sources of vegetable proteins are nuts, legumes, tofu, and certain vegetables, such as broccoli. As we will discuss later, vegetable proteins are healthier than animal proteins.
Copyright © 2015, 2018 by Kris Verburgh
Illustrations copyright © 2015 by CMRB, unless otherwise indicated Translation copyright © 2018 by The Experiment, LLC