describe the basic molecular structure of carbohydrates, and also identify their monomers and also polymers; perform the three subtypes the carbohydrates, and also describe their structure and function.

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Carbohydrates (carbo- = “carbon”; hydrate = “water”) contain the aspects carbon, hydrogen, and also oxygen, and only those aspects with a couple of exceptions. The proportion of carbon come hydrogen come 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 necessary molecules.

Carbohydrates room classified into three subtypes: monosaccharides, (mono- = ”one”, “alone”; saccharide = “sugar, sweet”) disaccharides (di = “two”), and also polysaccharides. (poly- = “many, much”). Monosaccharides and also disaccharides are also called simple carbohydrates, and are normally referred to as sugars. Basic carbohydrates are small polar molecules, containing number of –OH useful groups, which provides them hydrophilic (they dissolve fine in water). Polysaccharides, additionally called complex carbohydrates, are huge non polar molecules, and also they space not hydrophilic.

The figure below shows the most common monosaccharides: glucose, fructose and also galactose (six-carbon monosaccharides), and ribose and deoxyribose (five-carbon monosaccharides). Keep in mind that they space all nacivicpride-kusatsu.net using the suffix –ose, which way sugar. Carbohydrates are frequently nacivicpride-kusatsu.net “somethingose”.

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Figure (PageIndex1) this monosaccharides respect the ratio 1:2:1 mentioned above: glucose (C6H12O6), fructose (C6H12O6), galactose (C6H12O6), ribose (C5H10O5), deoxyribose (C5H10O4, this one is missing an oxygen). Note that carbohydrates have actually lots of hydroxyl functional groups (-OH)

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Figure (PageIndex2) there are different ways to stand for a glucose molecule (C6H12O6). 2 of the most usual are straight-chain kind (left) and also ring kind (right). Carbon atom in the vertices are not shown.

Disaccharides type by a covalent bond in between two monosaccharides. This form of bond between two monosaccharides is dubbed a glycosidic bond, and energy is neededto kind it.

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Figure (PageIndex3) The disaccharide sucrose is developed when a monomer that glucose and also a monomer of fructose join in a dehydration synthetic reaction to type a glycosidic bond. In the process, a water molecule is shed (not displayed in the figure). The shed water molecule is created by -OH and also -H displayed in red. Oxygen creates covalent bonds through glucose ~ above the left, and also fructose ~ above the right.

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Figure (PageIndex4) The most common disaccharides: sucrose (C12H22O11), lactose (C12H22O11), and also maltose (C12H22O11)

Polysaccharides are macromolecules written of repetitive units of the same building block, monosaccharides, similarly to a pearl necklace is written of countless pearls. We can also define polysaccharides together polymers assembled from numerous smaller covalently external inspection monomers. As displayed in the Figures and also Table below, three important polysaccharides in life organisms room glycogen, starch and also cellulose. Glycogen and starch are offered as energy stores in animal and also plant cell respectively, while cellulose gives structural assistance in plants and also fiber come our diets.

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