In this lesson, we will discuss the basic structure and function of these macronutrients and look at some general information on nutrition and diet . Carbohydrates Carbohydrates serve as the main energy source for the human body.
Animals break down carbohydrates during metabolism to release energy.
The basic unit in a carbohydrate is the sugar, or saccharide, unit. The simplest sugars are the monosaccharides, these are sugars that are composed of a single saccharide molecule. Three of the most common monosaccharides are glucose, fructose and galactose. Fructose is the main sugar found in many fruits. These structural differences are an important feature of the monosaccarides.