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
Sucrose : Definition, structure, characteristics and uses of Sucrose
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.
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.
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.
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.
Definition of Sucrose
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.
Galactose : Definition and characters
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.
Mannose : Definition and characters
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.
Relative Sweetness
Lactose-16
Maltose-32
Glucose-74
Sucrose-100
Fructose-173
Saccharin-500
Monaleline-2000
Pyranose and Furanose
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.