Glucose

Glucose is a hexose. The molecules shape is like that of a ring whose sides are formed by one oxygen atom and five carbon atoms. The side branches of the glucose molecule contains hydrogen atoms, OH groups and an alcohol group. These side groups and their positions are what determines the properties of a sugar and its nature.

Having the knowledge of the three dimensional structure of glucose can better help you in understanding the properties of carbohydrates.

Alpha and Beta Glucose

The two types of glucose molecules are alpha and beta glucose. The structures of alpha and beta glucose are shown below. As you can see both structures look the same but if you look closely you can see that Beta glucose is quite the opposite of alpha glucose, looking at the side groups you can see that beta glucose is formed by switching around the H and OH side groups of alpha glucose.

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(Image taken from biology 11)