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

To determine which substance provides the lowest amount of energy per gram for the human body, we need to consider the energy content of each option:

1. Tristerin (A): As a triglyceride, it is a type of fat that is high in energy, typically providing about 9 calories per gram.

2. Glycine (B): This amino acid is less energy-dense than fats, providing about 4 calories per gram.

3. Cellulose (C): As a polysaccharide, cellulose is not digestible by the human body and as such yields no energy, thus it can be considered to provide the lowest amount of effective energy per gram.

4. Glucose (D): This monosaccharide provides about 4 calories per gram.

Based on this analysis, the correct answer is C. cellulose (a polysaccharide) as it provides the lowest amount of energy per gram since it is not utilized by the human body.