![animal polysaccharide composed of glucose units animal polysaccharide composed of glucose units](https://image1.slideserve.com/2030758/storage-polysaccharides1-l.jpg)
When they are in a dry or powdered state, they exist as a linear molecule (top), but when dissolved in water they adopt a ringed form with oxygen being one of the members of the ring (bottom). Note that the molecules can exist in two different forms. The structures of three common monosaccharides are shown in the figure below. The names of most all sugars will end with this suffix. This suffix, -ose, means full, specifically, full of oxygen. Notice that the name of each of these sugars ends with the suffix -ose. Common monosaccharides include: glucose, fructose, galactose, ribose, and deoxyribose. Carbohydrates have the highest oxygen to carbon ratio of any of the important organic molecules. Hopefully, it is obvious that the monosaccharides contain a significant amount of oxygen, one for every carbon in the molecule. For example, if n = 6, the formula for the monosaccharide would be C 6H 12O 6 and if n = 5 the formula would be C 5H 10O 5. They contain from 3 to 7 carbons and have the general formula of (CH 2O) n where n ranges from 3 to 7 (5 or 6 being the most common). The monosaccharides (mono = one, saccharide = sugar) are the basic subunits of carbohydrates. We will now examine each of these types of carbohydrates. The disaccharides are composed of two monosaccharides linked together, and polysaccharides are composed of 3 or more monosaccharides linked together. Monosaccharides are the simplest form of carbohydrates and are composed of a single molecule or subunit. The name "saccharide" is derived from the Greek, meaning sugar. This classification is based on how many "subunits make up the molecule. There are three major classes of carbohydrates monosaccharides, disaccharides, and polysaccharides. Without glucose, nearly all animal life as we know it could not exist. If we were to identify the most important carbohydrate molecule on the planet, in terms of its ability to sustain life, we would undoubtedly select the monosaccharide glucose. Each year the earth converts more than 100 billion metric tons of CO 2 and H 2O into carbohydrates. Carbohydrates are the most abundant of the biomolecules. Carbohydrates, proteins, and lipids are used by cells as the building blocks for cells or for energy, while nucleic acids are the basis of the genetic material. These elements combine to form life-sustaining biomolecules, which can be divided into four groups: carbohydrates, lipids, proteins, and nucleic acids. There are roughly 92 naturally occurring elements on earth, but interestingly, only 4 (oxygen, carbon, hydrogen and nitrogen) make about 96% of the mass of the human body.