Structure of Glucose and Fructose

Introduction

Glucose and fructose are “monosaccharides or simple sugars” Glucose is favored by the human body for producing energy. “Plants and algae” produce glucose with the presence of “water and $\mathrm{CO_{2}}$”. Fructose is produced in the liver. The compounds contain atoms of three elements - “hydrogen, oxygen, and carbon”.

What are “Glucose” and “Fructose”?

“Glucose” is “monosaccharides” and sourced from “primary carbohydrates”. “Grape sugar” is another name for glucose. A “structure of pyranose ring” is formed by a “six-member ring” that represents glucose. The human body prefers glucose as a “primary source of energy”. It is an “aldohexose”.

“Fructose” also falls under the “monosaccharide category”. These are mainly sourced from “vegetables and fruits”. The “glycemic index” of “fructose compounds” is less than the “of glucose compounds”. The “fructose binding to cellular protein” is faster than “glucose” by “seven times”. “Fruit sugar” and “D-fructose” are the other name of this compound. It belongs to the “ketone functional group”.

“Characteristics of glucose”

Glucose has the following properties.

• Glucose falls in the category of “monosaccharide or simple sugar”.

• It belongs to the “aldehyde functional group”.

• The “molecular formula of glucose” is expressed as “$\mathrm{C_{6}H_{12}O_{6}}$”.

• Glucose is also known as “corn sugar, blood sugar, grape sugar and dextrose”.

• The compound has a density of “1.54 g/cm3”.

• The “molar mass of glucose” is “180.16 g/mol”.

• Glucose is produced from “glycogen breakdown and Photosynthesis”.

• “α-D-glucose” melts at “146°C” and “β-D-glucose” melts at 150°C”.

• “110 calories” of energy is contained in “one ounce of glucose”.

“Glucose structures”

Glucose belongs to the “carbohydrate group”. The molecules of glucose are chemically expressed as “$\mathrm{C_{6}H_{12}O_{6}}$” where an “aldehyde group” and “six carbon atoms” are present. This compound is called “aldohexose”. “Carbon, oxygen and hydrogen molecules” forms “chemical bonds” to construct the “molecules of glucose”. There are two forms of “glucose molecules”- “acyclic or open chain form” and “cyclic or ring form”. Glucose works as a prime source of energy in “living organisms”. The compound is naturally sourced from fruits and honey.

Figure 1: Structure of glucose and fructose

“Ring Structure” of fructose

The “chemical formula of fructose” is expressed as “$\mathrm{C_{6}H_{12}O_{6}}$” and it falls in the category of “monosaccharides”. These are also “simple sugars”. A “6-carbon polyhydroxy ketone” constructs this compound. A “cyclic six-member structure” is formed by the compound. The structure is responsible for “hemiketal and internal hydrogen bonding stability”. The structure is also termed “D-fructopyranose”. Fructose can be sourced from “honey, vine fruits, root vegetables, berries, flowers, and honey”.

Fructose characteristics

“Major characteristics of fructose” are mentioned below.

• “One ounce of fructose” generates “104 calories” of energy.

• It falls in the category of “monosaccharide or simple sugar”.

• “Levulose, fruit sugar and D-fructose” are other known names for fructose.

• “Fructose molecule’s chemical formula” is expressed as “$\mathrm{C_{6}H_{12}O_{6}}$”.

• Its “functional group” is “ketone”.

• The compound is produced by “glycogen breakdown, photosynthesis, and artificial industrial processes”.

• “One mol fructose” weighs “180.16 g”.

• Fructose melts at “103°C”.

• The “density of fructose” is “1.694 g/cm3”.

Foods containing glucose and fructose

Different “sources of foods” that contains “fructose and glucose” are as follows.

• Vegetables and fruits − “canned vegetables and fruits, candied or dried vegetables and fruits, ketchup, fruit drinks, and vegetables and fruits” are good sources of “fructose and glucose”.

• Dairy − Dairy products like “yoghurt, milk, and cheese” are glucose’s natural sources. “Sweetened cream cheese, ice cream, and whipped cream” also contain fructose.

• Grains − Glucose is sourced from grains. Fructose can be sourced from “glucose- made products like “baked goods, desserts, bread, crackers, chips, and cereal”.

• “Glucose and fructose” are also sourced from beverages and other industry-made products.

“Glucose and Fructose Compounds” - differences

“Glucose and fructose compounds” are “constitutional isomers” as they are distinct in “connected bonds”. Glucose and fructose are “aldehyde and ketone” respectively. When “hemiketal or hemiacetal formation” cyclize the two compounds, it forms a “6-ring sugar” from glucose and a “5-ring sugar” from fructose. Glucose is prioritized in the body as the most favourable energy form and “glucose metabolism” is possible in everybody cell. “Fructose metabolism” occurs only in the liver.

“Chemistry of D-Glucose”

In glucose, a “hydrogen-oxygen atom group” makes a bond with the “atom of carbon”. An “oxygen atom with double bonds” exists on the glucose molecule’s other side. The “fisher model of D-glucose” represents “oxygen atoms with double bonds” pointed down, and the “hydrogen-oxygen group” on the atom’s top position directs towards the right.

Figure 2 − “D-Glucose and L-Glucose”

“Chemistry of L-Glucose”

The “Fisher model” illustrates the structural differences between “L and D glucose”. In “L glucose”, the “oxygen and hydrogen atom groups” direct leftwards. The “structure of D and L glucose molecules” will look like reflections of each other if they are placed face to face.

Conclusion

“Glucose and fructose” are two “carbohydrate compounds” that can be found in animals and plants. The compounds are “monosaccharides” in nature. The compounds have characteristic similarities and differences. The “chemical formula” for glucose and fructose are the same and that is “$\mathrm{C_{6}H_{12}O_{6}}$”. The “glycemic index” is higher in glucose than fructose. In the human body, glucose works as a “primary source of energy”. Glucose is “aldehyde” and fructose is “ketone” in functional nature.

FAQs

1. What is the “ring structure” of fructose?

Fructose comes in the class of “monosaccharides or simple sugar”. The “molecular formula of fructose” is expressed as “$\mathrm{C_{6}H_{12}O_{6}}$”. Fructose is made of “6-carbon polyhydroxy ketone”. The “crystalline fructose” becomes a “6-membered structure”. That is responsible for “hemiketal and internal hydrogen bonding stability”.

2. What is the “role of fructose” in the body?

Fructose supplies energy to the body. Energy is produced in cells from fructose in the “aerobic breathing” process. In this process, “ATP” is generated by “burning fructose molecules”.

3. What are “carbohydrates”?

"Carbohydrates" are the "molecules of sugar". They are made of "carbon, hydrogen and oxygen" Glucose is formed by the "breakdown of carbohydrates" in the human body.