Carbohydrates: Structure and Classification

Study Notes

Carbohydrates are hydrates of carbon (H₂O of C).
They are the most abundant organic molecules in nature.
Their empirical formula is (CH₂O)ₙ.
They can be classified as polyhydroxyaldehydes or ketones, or compounds that produce these on hydrolysis.

Carbohydrates are a major dietary energy source (4 Cal/g) for all organisms.
They play a vital role in forming other organic compounds like fats, amino acids, and ketone bodies.
Carbohydrates (like glycoproteins and glycolipids) are integral components of cell membranes and participate in cellular processes like growth, adhesion, and fertilization.
They are structural components within organisms, including plant fibers (cellulose), insect exoskeletons, and the cell walls of microorganisms.
Carbohydrates serve as energy storage in the form of glycogen for immediate energy needs.

Monosaccharides are simple sugars categorized by the number of carbon atoms (trioses, pentoses, hexoses, and heptoses).
Aldoses contain an aldehyde group, while ketoses contain a ketone group.
Disaccharides are formed by the linkage of two monosaccharides via glycosidic bonds. Examples include maltose, sucrose, lactose, and trehalose.
Polysaccharides consist of many monosaccharide units linked together. Include homopolysacchrides (unbranched and branched) and heteropolysaccharides (two or more types of monomers). Examples of Carbohydrates are starch, glycogen, cellulose, inulin, dextrans, chitin, hyaluronic acid, heparin, chondroitin sulfate, dermatan sulfate, and keratan sulfate

Glyceraldehyde is an intermediate in glycolysis and the HMP shunt.
Erythrose is an intermediate in the HMP shunt.
Ribose is an intermediate in the HMP shunt and is a crucial component of nucleic acids.
Glucose provides energy and is a precursor for amino acids and fatty acids.
Galactose is a necessary component of milk and produces lactate.

D- and L- isomers are stereoisomers, differing only in the configuration around the chiral carbon atoms. Naturally occurring sugars are D-sugars.
Anomers are isomers that differ in configuration only around the anomeric carbon atom, which is the carbonyl carbon in the cyclic form. Alpha and beta forms are common anomers of sugars like glucose.
Optical activity refers to the ability of a substance to rotate the plane of polarized light. D-glucose is dextrorotatory (+). L-glucose is levorotatory (-).

Structures of D-glyceraldehyde, D-glucose, and D-fructose are shown in figures. Different ways of representing glucose (open chain, Fischer projection, Haworth formula) are described.
Formation of ring structures (pyranoses and furanoses) by hemiacetal or hemiketal formation is discussed.
Anomeric carbon is important in the cyclic form of monosaccharides, as it's involved in the formation of glycosidic linkages in sugars.

Oxidation, reduction, dehydration, esterification, and glycoside formation reactions are possible.

Reducing sugars have free aldehyde or ketone groups.
Identifying reducing sugars is possible through Benedict's test, Fehling's test, Barfoed's test and Osazone test.

Benedict's test uses Cu²⁺ to determine reducing sugars.
The test procedure includes heating a urine sample along with Benedict's reagent.
The test's color changes indicate varying glucose levels in urine;
The test is routinely used in diagnosing diabetes.

Homopolysaccharides are polymers of a single type of monosaccharide (starch, glycogen, cellulose, inulin, dextrans, and chitin).
Heteropolysaccharides are polymers with more than one type of monosaccharide (Hyaluronic acid, heparin, chondroitin sulphate, dermatan sulphate, and keratan sulphate).

Starch is the storage carbohydrate for plants, made up of amylose and amylopectin.
Glycogen is the primary storage carbohydrate for animals, highly branched.
Cellulose is a structural component of plant cell walls.
Inulin is found in some vegetables and is used in renal function tests.
Chitin is a structural component of exoskeletons of insects and crustaceans

Lactose intolerance is a condition resulting from a deficiency in the lactase enzyme, hindering lactose digestion.
Mucopolysaccharidoses (MPS) are inborn errors of metabolism stemming from flawed lysosomal enzyme function. Symptoms and effects are related to accumulation of glycosaminoglycans.. Proteoglycans and Glycoproteins.

Proteoglycans are proteins heavily glycosylated and found in the extracellular matrix.
Glycoproteins have less extensive glycosylation and are attached to integral membrane proteins.

A flowchart or figure showing the steps in the Benedict's test is missing from your provided material. More detailed information about the specific glycosidic linkages found in the various polysaccharides would enhance understanding.
More in-depth information from your files is necessary to get a complete summary across each topic.