Carbohydrates are an important group of physiological energy sources. The group of substances produced by photosynthesis makes up the largest portion of biomass on Earth.
What are carbohydrates?
Carbohydrates are an important group of physiological energy carriers. The group of substances produced by photosynthesis makes up the largest portion of biomass on Earth and is a component in a wide variety of foods. Biologically, carbohydrates are purely organic compounds of oxygen, hydrogen and carbon. They are produced by photosynthesis in plants. Carbohydrates are divided into four groups:
Monosaccharides (single sugars) such as glucose, dissacharides (double sugars) such as lactose and granulated sugar, and oligosaccharides (multiple sugars) such as raffinose. These three groups are widely grouped under the term “sugars.” They are water-soluble and taste slightly sweet. The fourth group consists of polysaccharides (polysaccharides), which are not water-soluble and have a neutral taste. The dietary fibers, which cannot be utilized by the body, also fall into this group. Stored are carbohydrates in the animal and human organism as glycogen, in the plant organism, however, as starch.
Meaning and function
Carbohydrates serve the body primarily as the most important energy supplier. Since the body can produce them itself only with additional energy expenditure than other nutrients, they should be ingested through food. The minimum amount required is about five grams per kilogram of body weight for an adult, with the majority consisting of polysaccharides. Almost all cells use carbohydrates as an energy source, but the brain plays a special role. Like red blood cells, it meets its energy needs exclusively from carbohydrates. If it is undersupplied, hunger quickly sets in. Carbohydrates are broken down into monosaccharides in the small intestine by various enzymes. The different types of carbohydrates, such as monosaccharides and polysaccharides, are available to the body at different rates. Monosaccharides pass immediately into the blood because they do not have to be broken down by the body first. For this reason, many people turn to glucose, a monosaccharide, when they have a particular energy requirement. This is why, for example, many students use glucose in an exam to supply their brain with a high amount of energy as quickly as possible. Dissaccharides can also be converted into energy relatively quickly. In a healthy and balanced diet, polysaccharides play a special role. Due to their long-chain structure, the breakdown takes place in several steps. The carbohydrates thus pass slowly and continuously into the blood and the satiety value increases. The energy supply is mainly regulated by the blood sugar level. If the value drops, a feeling of hunger sets in. Monosaccharides cause the blood glucose level to rise quickly because they are immediately available as an energy supplier. Polysaccharides ensure that the level remains constant for a long time. The body converts an excess of carbohydrates into glycogen, a multiple sugar, through the liver and muscles. When needed, glycogen can be converted back into glucose. The body has limited glycogen stores. When these are full, excess carbohydrates are converted to fat and stored. However, carbohydrates do not only play a role as a source of energy. They are equally important components in cell structure and play an essential role in regulating water and electrolyte balance.
Hazards, disorders, risks, and diseases
If carbohydrates are ingested in adequate amounts, they pose few dangers. However, excessive intake quickly leads to obesity. Especially in industrialized nations, considerably more monosaccharides and disaccharides are ingested with food than polysaccharides. This leads to a constant feeling of hunger and thus to further intake of rapidly available glucose. As a result, diseases such as type II diabetes, high blood pressure and heart disease occur. Since polysaccharides in particular contain many vitamins, insufficient intake can lead to deficiency symptoms, since monosaccharides contain far fewer vitamins due to their simple structure. Another risk is caries. Sugar attacks the teeth and, if not cared for properly, can lead to inflammation and serious damage. Untreated caries is another risk factor for heart disease.However, an insufficient intake of carbohydrates can have just as negative an effect. Since it is an important energy supplier, the first indications of a deficiency are fatigue, lack of concentration and poor performance. The water and electrolyte balance can become upset, which in the long term can lead to damage to the kidneys. If carbohydrates are lacking, the body converts proteins into carbohydrates. These are mainly found in the muscles, which is why the body first goes to the energy reserves in the muscles in the case of malnutrition. A balanced diet is therefore particularly important because many organs are also made up of muscle tissue.
