1. Ribose
Ribose is a monosaccharide with five carbons. It is called D-ribose. Ribose was discovered by scientist Emil Fisher in 1891. Its molecular symbol is C5H10O5. Its melting point is 95 degrees Celsius. It is a reducing sugar. It is called aldopentose sugar as it contains aldehyde group. Capable of ribose oxidation. It reacts with Hcl to produce furfuric acid. Ribose acts as the building block of RNA. A purine or pyrimidine base combines with ribose to form a nucleoside. Nucleosides combine with inorganic phosphates to form nucleotides. Nucleotides are then combined to form RNA. Ribose helps in the formation of sugars in the photophosphorylation process. Ribose is attached to biomolecules like ATP, NAD+, NADP+, FAD, Co-A etc. Dr. Siddiq Publications
2. Ribulose
Ribulose is a five-carbon monosaccharide. It is a reducing sugar. Its molecular symbol is C5H10O5. Since it contains a keto group, it is called a ketopentose sugar. Ribulose acts as a CO2 consumer in photosynthesis and produces ribulose 1, 5 bisphosphate. Ribulose 1, 5 bisphosphate is oxidized to form carboxyl compounds. Dr. Siddiq Publications
3. Deoxyribose
Deoxyribose is a five-carbon monosaccharide. It is a reducing sugar. Its molecular signaling
C5H10O4. It was discovered by scientist Phoebus Levene in 1929. It is called aldopentose sugar as it contains aldehyde group. Capable of deoxyribose oxidation. It is named deoxyribose because there is no oxygen attached to its 2nd carbon. Deoxyribose acts as a building block for DNA. A purine or pyrimidine base attaches to the 1st carbon of deoxyribose to form a deoxynucleoside. Deoxynucleosides and inorganic phosphate combine to form deoxynucleotides. Deoxynucleotides combine to form DNA. DNA transfers the hereditary characteristics of organisms through generations.
4. Glucose
Glucose is a six-carbon monosaccharide. It is a reducing sugar. Its molecular signal. It is called aldohexose as it contains aldehyde group. Ripe fruits and honey contain high amounts of glucose. As the ripe fruit contains 12-30% glucose, it is called grape sugar. It is called dextrose, corn sugar, grape sugar, blood sugar and D-glucose. Its relative sweetness is 74. Glucose is produced in the plant body in the process of photosynthesis. However, sugars are never stored in plant bodies. It acts as the primary component of respiration.
Properties of Glucose
(i) Glucose is a simple sugar.
(ii) It is a white granular substance.
(iii) It has a sweet taste.
(iv) It is soluble in water.
(v) It is slightly soluble in alcohol, but insoluble in ether.
(vi) It contains aldehyde group. Dr. Siddiq Publications
(vii) It is called aldose sugar.
(viii) It is a reactive sugar.
(ix) Glucose binds to proteins in the animal body to form glycoproteins.
(x) It reacts with phosphoric acid to form esters.
(xi) Its melting point is 146 degrees Celsius. (α- D glucose) and 150 degrees C. (β-D glucose).
Different types of glucose
(i) D Glucose (Dextrorotatory): If the hydroxyl (OH) group is attached to the right side of the 5th carbon of glucose.
It is called dextrorotatory or D glucose. Its rotation direction is to the right of the chiral center. It is a light activator. All natural glucose is D glucose. Dr. Siddique Publications
(ii) L Glucose (Laevorotatory): If the hydroxyl (OH) group is attached to the left side of the 5th carbon of glucose, it is called Laevorotatory or L glucose. Its rotation direction is to the left of the chiral center. It is a light activator. L-glucose is synthetically produced for use in diabetes medication and endoscopy. (The center along which the carbon molecules are linked is called the chiral center). Dr. Siddique Publications
(iii) α-D glucose and β-D glucose: Carbon 1 of glucose forms an oxygen bridge near carbon 5. A ring structure is formed as a result. An -OH group is generated due to the ring structure. If the -OH group is below the 1st carbon of glucose, it is called α-D glucose and if it is above the 1st carbon of glucose, it is called β-D glucose. α-glucose forms starch and β-glucose forms cellulose. D glucose is always present in the plant body.
Use of glucose
(i) Glucose is used as patient food. Quickly energizes the patient.
(ii) It is used in fruit preservation. Prevents fruit rot.
(iii) D-glucose is used to produce vitamin C from bacteria in the Richstein process.
(iv) Glucose is used in the preparation of calcium gluconate drugs.
(v) It plays a role in carbohydrate metabolism in the organism.
(vi) It is used to make citric acid, gluconic acid, bio-ethanol, sorbital etc.
(vii) It acts as a source of energy for sick people. Dr. Siddique Publications
(viii) Glycoproteins and glycolipids are formed from glucose.
(ix) Glucose is used in the process of glycolysis to generate energy.
5. Fuctose
Fructose is a six carbon monosaccharide. It is a reducing sugar. Since it contains a keto group, it is called a ketohexose. Fructose is so named because it was first identified from fruit. Sugarcane, beets, ripe fruits, nectar and honey contain high amounts of fructose. Ripe fruits contain a lot of fructose, so it is called fruit sugar or levulose. Its relative sweetness is 173. Fructose is the largest source of fructose in plants. Augustin Pierre Dubrunfaut discovered it in 1847. 2,40,000 tons of fructose are produced in the world every year. Dr. Siddiq Publications
Properties of fructose
(i) Fructose is a simple sugar.
(ii) It is a white granular substance.
(iii) It has a sweet taste.
(iv) It is soluble in water.
(v) It is soluble in hot alcohol.
(vi) It contains keto group.
(vii) It is called ketose sugar.
(viii) It is a reactive sugar.
Use of fructose
(i) Fructose is used in making sweets.
(ii) Used in making beverages, cakes, juices etc.
(iii) It acts as a source of energy.
(iv) It is used as delicacy for sick people.
(v) Fructose is used as a substitute for glucose in diabetic patients.
(vi) It combines with phosphoric acid to form esters.
(vii) It is used to prepare culture medium.
(viii) Male semen contains fructose. Therefore, sexual harassment can be proven by checking the presence of fructose in the genitals of women. Dr. Siddiq Publications
Chemical structure of fructose
Fructose is a six-carbon chemical compound with the molecular symbol C6H12O6. Fructose can be of two types based on the position of the -OH group. These are D and L fructose. If the -OH group on the 5th carbon of fructose is on the right side, it is called dextrorotatory or D fructose and if the -OH group on the 5th carbon of fructose is on the left side, it is called Laevorotatory or L fructose. Dr. Siddiq Publications
Why is fructose harmful to the human body?
A certain amount of fructose is metabolized in human liver cells. The liver cannot metabolize all the fructose when consuming high-calorie and high-fructose foods. Excess fructose is converted to fat and stored. Accumulated fat causes obesity, type-2 diabetes, cancer, heart disease, etc. in humans. So fructose is harmful to human body. Dr. Siddiq Publications
* Pyranose: Pyranose is hexagonal and has 5 carbons and 1 oxygen in its ring.
* Furanose: Furanose is pentagonal and has 4 carbons and 1 oxygen in its ring.
Relative Sweetness: Lactose-16, Maltose-32, Glucose-74, Sucrose-100, Fructose-173, Saccharin-500, Monaleline-2000. Dr. Siddiq Publications
6. Mannose: Mannose is a monosaccharide. It is an aldohexose sugar. It is the C-2 epimer of glucose. The molecular symbol for mannose is C5H10O5. It works metabolically in the human body. It plays an important role in glycosylation of proteins.
7. Galactose: Galactose is a monosaccharide. It is an aldohexose sugar. It is the C-2 epimer of glucose. The molecular symbol for galactose is C6H12O6. It is used to prepare culture media.
8. Sucrose : Definition, structure, characteristics and uses
The Latin word Sucrose means Sugar. Sucrose is a disaccharide. It is a non-reducing sugar. Sucrose is called sugar or beet sugar. Sugarcane, beets, carrots, flower nectar, pineapple etc. contain sucrose. The main raw material of honey is sucrose. Sugarcane contains 15% sucrose. It is twice as sweet as glucose. Carbohydrates are produced in plant leaves during photosynthesis and transported to various organs as sucrose. That is, sucrose is transported throughout the plant body. Sugar is sucrose. Analyzing sugar produces glucose and fructose. About 170 million tons of sugar are produced every year. English chemist William Miller (1857) coined the term sucrose.
Chemical structure of sucrose
Sucrose is a disaccharide and its molecular symbol is C12H24O11. Glucose and fructose combine to form sucrose molecules. The -OH group on the 1st carbon of α-D glucose and the OH group on the 2nd carbon of β-D glucose form a glycosidic bond. A molecule of water is released during the formation of the glycosidic bond. As a result, aldehyde and ketone groups are destroyed. So while glucose and fructose are reducing sugars, sucrose is a non-reducing sugar.
Characteristics of sucrose
(i) Sucrose is a white granular solid.
(ii) It is soluble in water, but insoluble in pure alcohol and ether.
(iii) It is twice as sweet in taste as glucose.
(iv) Its melting point is 188°C.
(v) Its wet analysis gives glucose and fructose.
(vi) It is a reactive sugar.
(vii) It is a non-reducing sugar.
Use of sucrose
(i) As Sweetener: Sucrose is most widely used in the preparation of sweetened foods.
(ii) Energy producing: It produces energy as a component of respiration.
(iii) Soap making: It is used to make transparent soap.
(iv) Commercial use: Sucrose is used commercially to make glucose and oxalic acid.
(v) Formation of polysaccharides: It helps in formation of polysaccharides. Dr. Siddique Publications
(vi) Stored energy: Sucrose acts as a reservoir of stored energy in the plant body.
(vii) As Bait: Flies, cockroaches, ants and other harmful insects are attracted by sucrose. Sucrose is used as poison bait to kill them. Dr. Siddique Publications
(viii) Acid making: Sucrose is used to make oxalic acid.
(ix) Production of honey: The main raw material of honey is sucrose.
(x) As a preservative: Sucrose is a natural preservative. It is used in food preservation.
(xi) Fermentation process: Sucrose is the main food of fungi. Fungi accelerate the fermentation process. This is why sugar is used along with the raw material in the fermentation process. Dr. Siddique Publications
(xii) In Horticulture: Sucrose creates an inhospitable environment for nematode worms in the soil. So sucrose is used in garden soil.
9. Lactose
Lactose is a disaccharide. Its molecular symbol is C12H22O11. Milk contains 2-4% lactose. One molecule of glucose and one molecule of galactose are joined by a glycosidic bond to form lactose. Lactase enzyme breaks down lactose into glucose and galactose. Dr. Siddiq Publications
10. Cellobiose
Cellobiose is a disaccharide. It is a reducing sugar. Its molecular symbol is C12H22O11. Cellobiose is produced by the partial breakdown of cellulose or lignin. Two molecules of glucose are joined by β-1,4 linkage to form cellobiose. Cellobiose is broken down into glucose under the influence of emulsin enzymes and acids. Bromine oxidizes cellobiose with water to form cellobionic acid. Dr. Siddique Publications
Function: Cellobiose acts as a structural component of cell wall.
11. Maltose
Maltose is a disaccharide. It is a reducing sugar. Its molecular symbol is C12H22O11. It is sweet in taste and its sweetness is 30-60% of sugar. Maltose is produced by partial distillation of sugar. Maltose is formed by the partial breakdown of starch. Two molecules of glucose are joined by α-1,4 linkage to form maltose. Maltose is used in malting barley to make beer.
12. Cellulose
Cellulose is a complex homopolysaccharide. The cell wall of autophagous plants is composed of cellulose. Cellulose is the most abundant organic material on Earth. Glucose is obtained by wet analysis of cellulose with hydrochloric acid or sulfuric acid or sodium hydroxide. Cellulose molecules contain β-1-4 glycosidic linkages. Neither animals nor humans can digest cellulose because they have no enzymes to break these β-1-4 glycosidic bonds. French chemist Anselme Payen (1838) discovered cellulose. Kobayashi & Shoda (1992) first produced synthetic cellulose. Dr. Siddiq Publications
Amount of cellulose
94% in cotton, 90% in linen or linseed, 90% in cellulose, 30-40% in grass, 60% in wood, 45% in dry hemp fiber, 58% in jute, 40% in sugarcane bagasse, 42% in wheat straw and 40-70% in organic soil. remains
Properties of Cellulose
(i) Cellulose is a tasteless, odorless and colorless substance.
(ii) It is chemically inert, but converts to glucose on wet analysis with strong acids.
(iii) It is insoluble in water and organic solvents. Dr. Siddique Publications
(iv) Its molecular weight ranges from 2 lakh to several lakh daltons.
(v) It is non-toxic and non-oxidizing.
(vi) It shows no color in iodine solution.
(vii) It is tough and fibrous.
(viii) It has no nutritional value.
(ix) Cellulose contains 44.41% carbon, 44.4% oxygen and 6.2% hydrogen.
Chemical structure of cellulose
Cellulose is a complex polysaccharide. It is composed of glucose molecules. Numerous glucose molecules are linked by β 1-4 glycosidic bonds to form cellulose. Cellulose is converted to glucose by hydrolysis with H2SO4 or HCl or NaOH.
Uses of cellulose
(i) Textile industry: Cellulose is used as the main raw material for textile industry. Rayon is made from cellulose as the raw material of the fabric.
(ii) As an explosive: It is used as a nitrate explosive. Cellulose is used as raw material for making nitrocellulose. Dr. Siddique Publications
(iii) For making furniture: Cellulose is the main material of wood and bamboo. Various types of furniture are made from bamboo and wood.
(iv) In paper industry: It is used to make filter paper and tissue paper. Cellulose insulators are made from newsprint paper in a recycling process. Cellulose insulator is an environmentally friendly coating.
(v) Digestion: Wood-boring insects use cellulose to digest wood.
(vi) In making gum: Methyl cellulose is used in making gum. Pure cellulose is mixed with water to make glue.
(vii) For making photographic film: It is used for making photographic, cellophane and celluloid.
(viii) In Biotechnology: Cellulose produced from fungi and bacteria is being used in biotechnology.
(ix) As Structural Material: Cellulose acts as the main structural material of plants. It forms leaves, stems and branches of plants. Dr. Siddiq Publications
(x) Skeletal system of plants: Cellulose provides strength and protection to plants. Cellulose is therefore called the skeletal system of plants.
(xi) Faecal formation: Most of the cellulose ingested with animal feed is excreted as faeces. Rafez relieves constipation. Cellulose is therefore essential for animal life. Dr. Siddiq Publications
(xii) Stationary phase: Cellulose is used as the stationary phase in thin layer chromatography.
Why can’t people digest cellulose?
Cellulase, the enzyme that digests cellulose, is not produced in the mammalian digestive system. However, a type of mitotic bacteria lives in the digestive system of cows, buffaloes, goats, deer, sheep etc. All these bacteria produce cellulose digesting enzyme cellulase. This enzyme aids in cellulose digestion by cleaving the β, 1-4 glycosidic bonds of cellulose. Humans cannot digest cellulose because the human digestive system lacks such mitotic bacteria. But the human diet must contain cellulose-type food. Because cellulose is essential for the production of stool. Dr. Siddiq Publications
13. Starch
The German word Starch means strong or hard or hard or rigid. Starch is a complex homopolysaccharide. Its molecular symbol is (C6H10O5)n. Carbohydrates or sugars produced in the process of photosynthesis are converted into starch and stored. Rice, wheat, potato, sorghum, banana, barley etc. are the main sources of starch. All these ingredients contain 70-80% starch. Round potato starch particles are the largest and 100µm. Rice starch particles are smallest and 2µm. The first reference to the extraction of starch from plants is found in the Natural History of Pliny the Elder (77-78 AD). Dr. Siddiq Publications
Properties of Starch /Religion
(i) Starch is tasteless, odorless and colorless substance.
(ii) It is a white granular powdery organic chemical substance.
(iii) It is insoluble in water, alcohol and ether.
(iv) Starch turns blue in iodine solution.
(v) It breaks down at high temperature into large dextin particles.
(vi) Starch cannot oxidize Fehling’s solution.
(vii) Iodine reacts with amylose of starch to produce black or black-blue color.
(viii) Iodine reacts with amylopectin of starch to produce red or purple color.
Chemical structure of starch
Starch is a complex polysaccharide. Starch is made up of amylose and amylopectin. It contains 22% amylose and 78% amylopectin. Amylose is composed of 200-1000 molecules and amylopectin is composed of 2000-200,000 molecules of glucose. Numerous glucose molecules are linked by α-1-4 glycosidic bonds to form starch. However, glucose molecules can be joined by α-1-6 bonds. Starch is hydrolyzed to glucose.
Use of starch
(i) Stored food: Starch is stored in the plant body as stored food. Starch in plant seeds, fruits and tubers serves as stored food. Starch stored in rice, wheat, bhutra, cassava, corn and round potato is used as human food.
(ii) Source of energy: It acts as a source of energy in the organism. Starch is converted into glucose to provide energy and carbon molecules to the body. Dr. Siddiq Publications
(iii) Respiration: It generates heat and energy in respiration.
(iv) Research: Starch is used in the laboratory to produce glucose and alcohol.
(v) In Paper Industry: Starch is the main ingredient in paper industry.
(vi) Preparation of glue: Pure starch is mixed with hot water to make glue. It is used to make corrugated board glue.
(vii) In titration: Starch is used as indicator during titration.
(viii) Textile use: Warp seizing agent is produced from starch. Warp shrinking agents reduce the rate of yarn tearing during fabric weaving. Starch is used for beating (laundry) cloth. Dr. Siddiq Publications
(ix) Oil exploration: Starch is used to increase the viscosity of drilling fluids, which are slippery fluids in oil exploration.
(x) Manufacture of cosmetics: Starch is used in the manufacture of talcum powder and other cosmetics.
(xi) Food processing: Starch is used to increase the density of food during food processing.
(xii) Production of Polymers: Starch is used to make eco-friendly bioplastics and other synthetic polymers.
(xiii) Fuel production: Biofuel corn ethanol is produced from starch in a fermentation process.
(xiv) Reproduction: Starch stored in the fruits, seeds, rhizomes and corms of the plant participates in the production of offspring in the next season.
(xv) In pharmaceutical industry: Starch is used as active ingredient carrier, tablet disintegrant and binder in pharmaceutical industry.
(xvi) Clothing starch: Liquid clothing starch is prepared by mixing pure starch with water. It is used in garments and laundry.
14. Glycogen
Glycogen is a nutrient complex homopolysaccharide. Glycogen is the main stored food in the animal body. Glycogen is stored in the liver, muscles, brain and stomach of vertebrates. But the liver has the most. Human liver contains about 100-120 grams of glycogen. Cyanobacteria or blue-green algae and some fungi (yeasts) have glycogen as stored food. Glycogen is called animal starch. French scientist Claude Bernard (1857) discovered glycogen.
Glycogen Properties/Religions
(i) Glycogen is a white powdery biochemical substance.
(ii) It is soluble in water. Dr. Siddiq Publications
(iii) It forms suspension in cold water.
(iv) Its molecular weight is 50 lakh daltons.
(v) On wet analysis it converts first to maltose and then to α-glucose.
(vi) It reacts with iodine solution to acquire a reddish violet color.
(vii) Heat removes its red color.
(viii) It reverts to black color on cooling.
(ix) Partially hydrolyzed to maltose and fully hydrolyzed to α-D glucose.
(x) It is converted into glucose in the process of glycolysis.
(xi) It keeps blood glucose levels normal.
Chemical structure of glycogen
Glycogen is a complex polysaccharide. It is composed of numerous α-glucose molecules. In the process of glycogenesis, 30,000 molecules of glucose combine to form glycogen. Glucose molecules are linked by α-1-4 glycosidic bonds to form glycogen. Branching of glycogen occurs through α-1-6 linkage. Each branch contains 10-20 glucose molecules. Their molecular weight is 106-107 daltons. Glycogen is hydrolyzed into glucose. Glycogen is converted to glucose when needed to provide carbon and energy. For this reason, glycogen is called animal starch.
Utilization of glycogen
(i) Stored food: Glycogen is stored in the animal body as stored food.
(ii) Glucose production: Glucose is produced from liver glycogen in the process of glycogenesis.
(iii) Muscle energy: Glycogen stored in skeletal and cardiac muscles provides extra energy to muscles.
(iv) Regulation of blood volume: It regulates blood volume in the body. Increases blood glucose levels by breaking down liver glycogen. Dr. Siddiq Publications
(v) Formation of suspension: It forms colloidal suspension in water.
(vi) Production of Surfactant: Glycogen begins to accumulate in the pulmonary cells of the fetal baby at 23 weeks of gestation. Stored glycogen produces lung surfactant.
(vii) Energy storage: Glycogen production and storage takes place in the liver cells of animals. It acts as a stored energy reservoir secondary to the glucose cycle in the animal body. Dr. Siddiq Publications
(viii) Energy supply to the brain: A small amount of glycogen is stored in brain cells. It powers the conscious brain.
15. Inulin
Inulin is a polysaccharide. It is dissolved in cells. It contains 30-35 fructose units. Plants of the family Asteraceae such as dahlia, chicory, Jerusalem artichoke etc. contain inulin. Inulin is found in onions and garlic.
16. Chitin
Chitin is a polysaccharide. A simple linear homopolymer of N-acetyl-D-glucosamine residues is called chitin. Chitin is one of the most abundant substances on earth. It is the second most important polymer in the world. Its chemical symbol is (C8H13O5)n. Numerous D amino monomers are joined by β-1, 4 glycosidic bonds to form chitin.
Properties of chitin
(i) Chitin is insoluble in water, organic acids and weak acids.
(ii) It is soluble in strong formic acid and methane sulphonic acid.
(iii) It is stronger and more stable than cellulose.
(iv) Chitin is decomposed by strong acids to acetic acid and u-amino glucose.
(v) It is similar to keratin protein.
Source of Chitin: Chitin forms the exoskeleton or shell of animals like moths, crabs, shrimps, lobsters, squids. The cell walls of yeast and fungi are made of chitin. Dr. Siddique Publications
Uses of chitin: Chitin has uses in herbal, industrial and biotechnology.