why do proteins need to be made for the body

Proteins are astonishing nutrients because they are so fundamental to our very architecture as humans. Our cells and organs, our muscles, our connective tissue, and even our bones could not hold together as the key body parts they are without the help of protein. This importance of protein to our very structure is only one function played by proteins, however. Proteins are equally important to our metabolism because all enzymes in our body that help trigger chemical reactions are proteins. Many of our most important regulatory hormones, like insulin, are also proteins. So are many of the key molecules in our immune system as are the major molecules used to carry nutrients around our body. Whether they are structural proteins, immunoproteins, hormonal proteins, transport proteins, or enzymes, proteins are of utmost importance to our health.

The importance of protein to our life is reflected in the term itself: protein is derived from the Greek term protos, which means "taking first place. "
Proteins are made up of smaller molecules called amino acids that are strung together by chemical bonds like beads on a chain. To become an active, functional protein, this string of amino acids folds in on itself forming a twisted and entwined three-dimensional structure. Proteins come in many sizes. Some chains of amino acids are quite small, like the hormone insulin that is only 51 amino acids long. Most proteins, however, are larger. Most of proteins in your body contain between 200-400 amino acids.

Amino acids are similar to simple sugars, insofar as they serve as the building blocks for all other molecules found within their nutrient category. Just as carbohydrates are composed of monosaccharides, proteins are composed of amino acids. And, in a manner similar to the digestion of carbohydrates, your body can break proteins down to amino acids during the digestion process, taking in only the small single amino acid unit, or sometimes a two or three amino acid unit. Like carbohydrates, amino acids are composed of carbon, hydrogen, and oxygen. However, unlike carbohydrates, amino acids also contain nitrogen. In fact, amino acids are your body's primary way of getting nitrogen. Many people who have jumped on the high-protein/low-carb bandwagon think that they can pack away as much protein as they like.

But experts urge caution. The reasons why have to do with how high-protein/low-carb diets are thought to lead to. When people eat lots of protein but few carbohydrates, their metabolisms change into a state called. Ketosis means the body converts from burning carbs for fuel to burning its own fat. When fat is broken down, small bits of carbon called are released into the bloodstream as energy sources. Ketosis, which also occurs in, tends to suppress appetite, causing people to eat less, and it also increases the body's elimination of fluids through urine, resulting in a loss of water. Christopher D. Gardner, PhD, assistant professor of medicine at Stanford University in Palo Alto, Calif. , tells WebMD that high- like the regimen may trade short-term benefits for long-term health consequences.

Among the risks: The body produces when it breaks down protein. No one knows the long-term risks of higher levels of ammonia in the body. Also, there is evidence to suggest that people who eat high- typically excrete excess in their urine, says Deborah Sellmeyer, MD, assistant professor of medicine and director of the Center for at the University of California at San Francisco. This suggests that the body is releasing stores of into the bloodstream to counteract an increase in acids caused by protein consumption ( buffers, or neutralizes, acids). Too much calcium loss could lead to down the road, Sellmeyer says.

Lastly, there are the obvious concerns. Carbohydrate foods shunned by some people on low-carb diets include, which are the best sources for, fiber, and -- that help prevent disease. By contrast, animal foods that are high in protein are usually also high in, which increase the risk for, and several types of. The American Association warns: "Reducing consumption of [carbs] usually means other, higher-fat foods are eaten instead. This raises even more and increases cardiovascular risk. " The AHA also notes that by concentrating on protein sources and skipping carbs, dieters may be getting too much salt, and not enough calcium, or, which are typically found in fruits, vegetables, and whole grains.