Describe the general molecular structure of carbohydrates, and identify their monomers and polymers; list the three subtypes of carbohydrates, and describe their structure and function.
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Carbohydrates (carbo- = “carbon”; hydrate = “water”) contain the elements carbon, hydrogen, and oxygen, and only those elements with a few exceptions. The ratio of carbon to hydrogen to oxygen in carbohydrate molecules is 1:2:1. The component carbon (C, carbo-) and the component water (H20, -hydrate) give the name to this group of organic molecules.
Carbohydrates are classified into three subtypes: monosaccharides, (mono- = ”one”, “alone”; saccharide = “sugar, sweet”) disaccharides (di = “two”), and polysaccharides. (poly- = “many, much”). Monosaccharides and disaccharides are also called simple carbohydrates, and are generally referred to as sugars. Simple carbohydrates are small polar molecules, containing several –OH functional groups, which makes them hydrophilic (they dissolve well in water). Polysaccharides, also called complex carbohydrates, are large non polar molecules, and they are not hydrophilic.
The figure below shows the most common monosaccharides: glucose, fructose and galactose (six-carbon monosaccharides), and ribose and deoxyribose (five-carbon monosaccharides). Note that they are all nanadechworld.com using the suffix –ose, which means sugar. Carbohydrates are often nanadechworld.com “somethingose”.