Which of the following carbohydrate units is also known as saccharides?

The term "saccharides" refers specifically to the sugar units that constitute carbohydrates. These are classified into different categories, including monosaccharides (simple sugars like glucose and fructose), disaccharides (combinations of two monosaccharides, such as sucrose or lactose), and polysaccharides (complex carbohydrates like starch and glycogen).

Recognizing saccharides as carbohydrate units is essential for understanding their role in nutrition, as they are a primary source of energy for the body. Carbohydrates, being one of the three macronutrients (along with proteins and fats), play a vital role in various bodily functions, including metabolism and energy production.

The other choices do not pertain to carbohydrate units. Lipids refer to fats and oils, which are another type of macronutrient. Nutrient density is a concept related to the amount of nutrients per calorie in a particular food, which does not define any carbohydrate unit. Dispensable amino acids refer to a category of amino acids that the body can synthesize and are not related to carbohydrates at all. Therefore, identifying saccharides as carbohydrate units provides clarity about their fundamental nature in human nutrition.