What Is Glucose?

Carbohydrates, sugars, starches and cellulose provide energy sources for cells. While cellulose is the principle structural portion of plant cell walls, sugars such as glucose are necessary for maintenance of homeostatic conditions in the blood of both humans and animals.

Features

Glucose, a monosaccharide, consists of 6 carbon atoms, 12 hydrogen atoms and 6 oxygen atoms. It is the main source of energy for plant and animal life, including human beings. Monosaccharides are carbohydrates generally made up of three to seven carbon atoms.

In the chemical structure of a monosaccharide, a hydroxyl group (OH) is bonded to each of the carbon atoms, except one. The leftover carbon is double-bonded with an oxygen atom, which is a carbonyl group (CHO). The location of the carbonyl group determines whether the carbohydrate is an aldehyde or a ketone.

Significance

The huge number of hydroxyl groups with the carbonyl group gives the monosaccharide molecule hydrophilic properties. Hydrophilic properties means it interacts readily with water.

Cells quickly oxidize glucose in a process called cellular respiration. The waste product of this process is carbon dioxide. The energy contained within a molecule of glucose is drawn out and then used by the cell to drive its primary work of maintenance, reproduction and repair.

Function

The most plentiful monosaccharide on the planet, glucose production begins inside the leaves of plants through the process of photosynthesis. In the presence of sunlight, green plants absorb solar energy, transforming it into chemical energy. This chemical energy, in the form of ATP and NADPH, is then used to produce glucose.

ATP is short for adenosinetriphosphate, and it is the principle energy molecule used to drive cell processes, such as the manufacturing of glucose in plants, and in the cellular respiration processes of animals and people. Nicotineamide adenosine dinucleotide phosphate (NADPH), an electron acceptor, provides direct energy to drive certain reactions, including photosynthesis.

Considerations

The term carbohydrate means "water of carbon," and reflects the 2:1 ratio of hydrogen to oxygen, which is equal to that of water (H20). Those holding one unit of sugar, such as glucose, are called monosaccharides, those holding two are called disaccharides and three are called polysaccharides, which are complex carbohydrates (starches).

Benefits

Dextrose, a form of glucose, is used as an intravenous solution administered to people who have been injured or are sick. Glucose is converted rather rapidly in aqueous solution and can be injected directly into the bloodstream, providing a fast energy source for bodily tissues needing repair and sustenance. Cells can also use monosaccharides to make other organic molecules.