In the last few years, carbohydrates have become a major topic in the world of nutrition. Eat lots of them - don't eat any; the debate rages on like a gigantic sugary pendulum. But what exactly is a carbohydrate and what are the functions of carbohydrates in human cells? Certainly you need some carbohydrates, but what exactly do they do?
Carbohydrates are a broad classification of organic chemicals that contain only carbon, oxygen, and hydrogen. The carbon atoms form the "backbone" of all carbohydrates, and are what makes chemists refer the them as "organic".
Carbohydrates play major roles in human metabolism. In fact, you couldn't live without them. The structure of various carbohydrates varies tremendously - this category of chemicals is so massive that a complete list would take many pages. Carbohydrates can also be referred to as "saccharides".
In humans, carbohydrates are an essential form of storing energy. They can be combined in various ways to produce high energy compounds that your body uses for immediate and long-term energy demands. You are certainly already familiar with a common carbohydrate: glucose. Yes, sugars are all carbohydrates.
Carbohydrates are easier to metabolize for energy than are fats. Because of this, they are typically used for short-term immediate energy needs. They can be rearranged in to fats and other long-term storage molecules if needed by the body. Fatty acids, lipids, and cholesterol are all synthesized by your body from more simple carbohydrates.
Aside from energy storage, carbohydrates have other functions in human cells. A lesser known use for them is to form the backbone and basic structure of DNA and RNA. These are the genetic molecules that code for all the things that make you who you are. Without carbohydrates, DNA would not exist as we know it.
Many other coenzymes (molecules that aid in chemical reactions) are made with carbohydrates as the primary structure. These molecules serve such a wide range of functions, that it often takes a degree in cellular biology to fully understand even a reasonable fraction of the uses your cell have for carbohydrates.
So next time you sit down with that big bowl of pasta and start to feel guilty about all the carbs it has, remind yourself that carbohydrates are not the enemy. In fact, you wouldn't live long without them. All good things must be done in moderation however, but a careful intake of carbohydrates is an essential part of a balanced and healthy diet.