Question

Which of the following statements about glucose, galactose, and fructose is most likely true?

a) They are all monosaccharides.
b) They are all disaccharides.
c) They are polysaccharides.
d) They are all complex carbohydrates.

Answer 1

Glucose, galactose, and fructose are all monosaccharides with the same molecular formula, C6H12O6, but with distinct structural arrangements. Glucose and galactose are aldoses, while fructose is a ketose.

Step-by-step explanation:

Glucose, galactose, and fructose are all monosaccharides, which means they are the simplest form of sugar and the most basic units of carbohydrates. They are also referred to as isomeric hexoses, meaning they share the same molecular formula, C6H12O6, but their atoms are arranged differently.

Glucose and galactose are classified as aldoses, which means their structure includes an aldehyde group. On the other hand, fructose is classified as a ketose, which means it has a ketone group. This structural variation causes differences in their chemical behavior.

Galactose is a component of lactose, or milk sugar, and fructose is found in sucrose, as well as in many fruits. The presence of multiple asymmetrical carbons creates diverse spatial arrangements contributing to the unique properties of these sugars.