GLYCERALDEHYDE It is the smallest sugar It has got three carbons Its carbon 2 is asymmetric carbon All monosaccharides having more than 3 carbons will have two or more asymmetric carbon atoms. For D and L designation all monosaccharides are compared with glyceraldehyde. Thus it is called a reference sugar.
MONOSACCHARIDES Monosaccharides are carbohydrates that cannot be hydrolyzed to obtain smaller molecules of carbohydrate. White crystalline solids, very soluble in water, have sweet taste.
Glucose Glucose is by far the most common carbohydrate and classified as a monosaccharide, an aldose, a hexose, and is a reducing sugar. Principal MS utilized for energy purposes.
It is also known as dextrose, because it is dextrorotatory. Glucose units combine and give rise to: Glycogen Starch Cellulose
Glucose is also called blood sugar as it circulates in the blood at a concentration of 65-110 mg/mL of blood. Normally trace amounts in urine Increased amounts in diabetes mellitus.
Glucose is initially synthesized by chlorophyll in plants using carbon dioxide from the air and sunlight as an energy source. Glucose is further converted to starch for storage.
an aqueous sugar solution contains only 0.02% of the glucose in the chain form, the majority of the structure is in the cyclic chair form.
Fructose Fructose is classified as a: monosaccharide, the most important ketose sugar, a hexose, and is a reducing sugar. Fructose, along with glucose are the monosaccharides found in disaccharide, sucrose. Sweetest of all sugars.
Fruit juices. Honey. Hydrolysis of cane sugar and of inulin. Can be changed to glucose in the liver and so used in the body. Main source of energy for the spermatozoa Levorotatory (in sucrose dextrorotatory) Hereditary fructose intolerance
Galactose Galactose is classified as a: monosaccharide, an aldose, a hexose, and is a reducing sugar.
Hydrolysis of lactose Galactose is more commonly found in the disaccharide, lactose or milk sugar. It is found as the monosaccharide in peas. Constituent of glycolipids and glycoproteins. C-4 epimer of glucose Galactose is part of nerve and brain biochemicals, so milk is essential to infants.
Pentoses Xylulose- uronic acid pathway Arabinose and xylose- glycoproteins Ribose - RNA Deoxyribose - DNA
` All are classified as: monosaccharides, aldoses, Pentoses, and are reducing sugars.
Ribose Ribose and its related compound, deoxyribose, are the building blocks of the backbone chains in nucleic acids, better known as DNA and RNA. Ribose is used in RNA and deoxyribose is used in DNA.
The presence or absence of the -OH group on carbon (#2) is an important distinction between ribose and deoxyribose. Ribose has an alcohol at carbon # 2, while deoxyribose does not have the alcohol group. Deoxy hexoses also present in milk and blood group substances.
Disaccharides Three common disaccharides: Sucrose — common table sugar = glucose + fructose Lactose — major sugar in milk = glucose + galactose Maltose — product of starch digestion = glucose + glucose
The resulting linkage between the sugars is called a glycosidic bond. The molecular formula of each of these disaccharides isC 12 H 22 O 11 = 2 C 6 H 12 O 6 − H 2 O
Sucrose Sucrose is made from glucose and fructose units Sucrose or table sugar Cane, beet sugar, Pineapple Has no free anomeric carbon Is a non-reducing sugar
Dextrorotatory Invert sugar No osazone crystals In sucrase deficiency, malabsorption leads to diarrhea and flatulence
Maltose Glucose+ Glucose Digestion by amylase or hydrolysis of starch. Reducing sugar Baby and invalid foods
Lactose Glucose + Galactose Milk sugar May occur in urine during pregnancy In lactase deficiency, malabsorption leads to diarrhea and flatulence Certain bacteria can ferment lactose to lactic acid - souring of milk. ( lactobacillus)