The substances below are present in the food we eat - VCE - SSCE Chemistry - Question 3 - 2005 - Paper 1

Cellulose is a polysaccharide that is not digestible by humans, and as such, it provides the lowest energy contribution per gram compared to the other options. Triglycerides like tristerin, amino acids like glycine, and monosaccharides like glucose provide significantly more energy per gram because they can be metabolized by the body.

To elaborate, triglycerides can yield about 9 kcal/g, while glucose and amino acids yield approximately 4 kcal/g. Cellulose, however, typically offers negligible energy since it cannot be broken down by human digestive enzymes.