Glucose as the sole metabolic fuel: The possible influence of formal teaching on the establishment of a misconception about energy-yielding metabolism among students from Rio de Janeiro, Brazil

Abstract

Energy-yielding metabolism is an important biochemistry subject that is related to many daily experiences and health issues of students. An adequate knowledge of the general features of EYM is therefore important, both from an academic and social point of view. In a previous study, we have shown that high-school students present the misconception that carbohydrates, especially glucose, are the sole metabolic fuel for ATP production by human cells. In the present work, we investigated the possible origins of the occurrence of this misconception among students. The analysis of students' answers to questionnaires indicated that the misconception appears as soon as in the 8th grade and remains unchanged throughout subsequent school years. The analysis of grade textbooks showed that the misconception is likely to be a consequence of the teaching of nutrition in the 8th grade, when a single function is emphasized for each nutrient. The energetic function is mainly associated with carbohydrates, while proteins and lipids are considered structural and storage molecules, respectively. An extreme similarity was observed between students' knowledge of nutrient's function and textbook contents. Analysis of high-school textbooks suggested that the misconception would be reinforced because of the detailed teaching only of glucose metabolism, with rare mention of lipids or amino acids as metabolic fuels. The consequences of that approach are discussed and suggestions are made on an alternative teaching of energy-yielding metabolism. © 2008 by The International Union of Biochemistry and Molecular Biology.