Carbohydrate Notes PDF

Carbohydrate +-----------------------------------------------------------------------+ | Slide 1: Bio-molecules, General Idea | | | | **Bio-molecules are molecules that occur naturally in living...

Carbohydrate +-----------------------------------------------------------------------+ | Slide 1: Bio-molecules, General Idea | | | | **Bio-molecules are molecules that occur naturally in living | | organisms. All forms of life are composed of biomolecules | | only. Biomolecules are organic molecules especially macromolecules | | like carbohydrates, proteins in living organisms and also lipid, | | nucleic acids etc.** | | | | **It also includes small molecules like primary and secondary | | metabolites, and natural products. Biomolecules consist mainly of | | carbon and hydrogen with nitrogen, oxygen, sulfur, and phosphorus. | | Biomolecules are very large molecules of many atoms that are | | covalently bound together.** | | | | Slide 2: **CARBOHYDRATE, GENERAL IDEA** | | | | - **Carbohydrates are the most abundant organic molecules in | | nature. They are more simply defined as poly-hydroxy aldehydes or | | ketones and their derivatives. Many have the empirical formula | | (CH~2~O)n, which originally suggested that they are hydrate of | | carbon. Generally, but not always, the hydrogen and oxygen in | | carbohydrate are** **present** **in the proportion of two | | hydrogen atoms to one oxygen atom, as in water (H~2~O).** | | | | - **Many substances but not carbohydrate also contain hydrogen and | | oxygen in the proportion of water, such as acetic acid | | (C~2~H~4~O~2~) and lactic acid (C~3~H~6~O~3~). Again, also some | | carbohydrates such as Rhamnose (C~6~H~12~O~5~) do not contain | | hydrogen and oxygen in the proportion of H~2~O.** | | | | | | | | - **Therefore, carbohydrates are actually or potentially | | (convertible) to hydroxyl aldehydes or ketones, and in most cases | | they are poly- hydroxy aldehydes or ketones.** | | | | | | | | - **It has been latter found that sugars are found in the ring | | structure. Haworth suggested that the six- membered ring forms of | | the sugars be called "Pyranoses" as because Pyran possesses the | | same ring of five Carbons and an Oxygen.** | | | | - **Haworth also suggested that the five- membered ring forms of | | the sugars be called "Furanose" as because Furan possesses the | | same ring of four Carbons and one oxygen.** | | | | Structure: Glucose, Galactose, Mannose and Fructose | | | | Disaccharide: Sucrose, Maltose and Lactose | | | | Slide 4: Properties of Light | | | | - **Ordinary Light: Move in all directions,** | | | | - **Plane polarized light move only in one direction, as direction | | (see Figure on right below)** | | | | | | | | - **Plane polarized light is rotated clockwise, (to the right)** | | | | **or counterclockwise (to left) when passed through** | | | | **enantiomers. Direction and extent of rotation will depend** | | | | **upon the enantiomer. Same concentration of two** | | | | **enantiomers rotate light to same extent but in opposite** | | | | **direction.** | | | | ** ** | | | | **Slide 5: Short Questions** | | | | - **What is the Origin of Bio-molecules?** | | | | | | | | - **What are the 4-Elements Most Characteristic of Bio-molecules?** | | | | | | | | - **What are the Functions of Bio-molecules?** | | | | | | | | - **What is the Most Important Bio-molecule?** | | | | | | | | - **What is the Structure of a Bio-molecule?** | | | | | | | | - **How do we Identify Bio-molecules?** | | | | | | | | - **What is the Summary of Bio-molecules?** | | | | - **Definition: A bio-molecule is a chemical compound found in | | living organisms. These include chemicals that are composed of | | mainly carbon, hydrogen, oxygen, nitrogen, sulfur and phosphorus. | | Bio-molecules are the building blocks of life and perform | | important functions in living organisms.** | | | | - **Who is the Father of Bio-molecules?** | | | | | | | | - **What is the Most Common Carbohydrate in Biochemistry?** | | | | - **Glucose. Carbohydrates have been given non-systematic names, | | although the suffix \-- ose is generally used. The most common | | carbohydrate is glucose (C~6~H~12~O~6~).** | | | | - **Which is the Smallest Carbohydrate?** | | | | | | | | - **Which Carbohydrate is Sweetest?** | | | | | | | | - **What is the Best Type of Carbohydrate?** | | | | | | | | - **Are Carbohydrates Good for Metabolism?** | | | | | | | | - **What is the Difference Between Good and Bad Carbohydrates?** | | | | | | | | - **Is Fiber a Type of Carbohydrate?** | | | | | | | | - **What is the difference between Glucose and Dextrose?** | | | | | | | | - **Is dextrose the same as glucose?** | | | | **‌Dextrose is a type of sugar that usually comes from corn or wheat. | | It is almost identical to glucose, which is the sugar found in the | | bloodstream. For that reason, it can be quickly used as a source of | | energy by the human body. Dextrose is often used in foods as an | | artificial sweetener or a preservative.** | | | | - **Which is the Smallest Carbohydrate?** | | | | | | | | - **Which is Simplest Carbohydrates?** | | | | **Slide 6: Molisch Test: Colour test for identification of sugar-** | | | | **This is a very sensitive general reaction for sugar detection. It | | is performed by mixing a few drops of an alcoholic solution of α -- | | napthol with the sugar solution and stratifying the mixture over | | concentrated H~2~SO~4~. A red or violet ring appears at the junction | | of the liquid, indicating the presence of sugar.** | | | | **Amino sugar, sugar alcohols and carboxylic acid do not give the | | test while 2- keto aldonic acids give green colour.** | | | | ** ** | | | | **Slide 7: Osazone Test** | | | | **A monosaccharide on being heated to 100^o^C with Phenyl hydrazine | | in Acetic acid, is first changed to a sugar Phenyl hydrazone, the | | product then reacts with excess of the reagent to form a sugar | | osazone, which precipitates as characteristic yellow or microscopic | | crystals having characteristic melting points. This is the basis of | | osazone test used to distinguish between sugars. However, Glucose, | | Fructose and Mannose form the same osazone and so cannot be | | differentiated from each other by this test. As in osazone formation, | | only C-1 and C-2 are involved that are rearranged. On the other hand, | | C-3 to C-6 of these sugars are of same configuration, so they form | | same osazone.** | | | | **Slide 8: Mutarotation** | | | | **E. Fischer treated glucose with methyl alcohol and HCl, and | | obtained a product which Van Ekenstein showed consisted of two | | isomeric methyl derivatives of glucose. These substances had specific | | rotation of + 159^o^ and -34^o^, and were named as Methyl -- α -- D | | -- glucoside and Methyl -- β -- D --glucoside, respectively.** | | | | **It will be seen that C -- 1 has become asymmetric and this accounts | | for two isomers. Dubrunfaut first noticed that the optical rotation | | of a freshly prepared glucose solution gradually decreases and | | finally becomes constant. This changes in rotation of sugar solutions | | upon standing is a general properties of a reducing sugar, with the | | exception of some ketoses and is called mutarotation.** | | | | **Slide 9: Continuation** | | | | - **The correct interpretation of mutarotation was provided by | | Tanret, who prepared two isomeric forms of D -- Glucose by | | crystallization under different conditions. When D -- Glucose is | | crystallized from water or dilute alcohol at room temp., a form | | separates, having an initial specific rotation of + 112^o^, which | | changes to +52.5^o^. If however, crystallization takes place from | | water at temperature above 98^o^C, a different form separates | | having an initial specific rotation of + 19^o^, which changes to | | +52.5^o^ is obtained. The first of these isomers is called α -- | | D - Glucose and the second is β -- D -- Glucose.** | | | | - **α -- D Glucose D - Glucose β -- D -- Glucose** | | | | **+ 112^o^ 52.5^o^ +19^o^** | | | | **Slide 10: Invert Sugar** | | | | **Sucrose is known as the invert sugar. It is dextrorotatory and its | | rotation is** | | | | **+ 66.5^o^, but the hydrolytic product of sucrose are levorotatory | | having a specific rotation of** **-- 19.5^o^. As the levorotation of | | fructose is greater than the dextrorotation of glucose, so after | | hydrolysis, the rotation of the products invert the rotation of the | | resulting mixtures of glucose and fructose, and so it is called | | invert sugar.** | | | | **Slide 11: Amino Sugar** | | | | **Sugars containing an amino (-** NH~2~**) group are called amino | | sugars, e.g., D -- glucosamine, D -- galactosamine etc. These amino | | sugars are found by the replace of HO -- group attached to the carbon | | atom, C -2 of the sugar by an amino group. Glucosamine is a | | constituent of hyaluronic acid, which is the organic constituent of | | lobster shell and fairly distributed in nature. Galactosamine is a | | constituent of muco -protein. Several antibiotic such as | | erythromycin, carbomycin contains amino sugars. The amino sugars are | | believed to be related to the antibiotic activity of drug. | | Erythromycin contains a dimethyl amino sugars. Carbomycin contains | | the first known, Amino sugar, 3 -- amino -- D -- ribose. \* N -- | | Acetyl glucosamine : NHCOCH~3~ in place of - NH~2~** | | | | **Slide 12: Structure** | | | |  | | | | **Slide 13: BIOLOGICAL IMPORTANCE OF CARBOHYDRATE** | | | | - **Carbohydrates are widely distributed in plant and animal | | tissues. The major functions are as follows:** | | | | **Slide 14: Continuation** | | | | **7. Carbohydrates form a part of genetic material like DNA and RNA | | in the** | | | | **form of deoxyribose and ribose sugars.** | | | | - **8. Carbohydrates are basically the main fiber of the diet or | | provide the bulk fiber for better digestion.** | | | | - **9. As the primary product of plant photosynthesis, so they are | | the metabolic precursors of all other organic compounds.** | | | | - **10. Some carbohydrates are necessary in the diet so that the | | oxidation of fats can proceed normally.** | | | | - **11. They can be cell membrane components mediating | | intercellular communication.** | | | | **12. They can be part of the body's extracellular ground | | substance.** | +-----------------------------------------------------------------------+