ATP and the textbook trap

Students often have an intrinsic belief in the infallibility of textbooks. It is in the textbook and so it must be right. These students worry when different textbooks give different information. For example, the production of adenosine triphosphate (ATP) in aerobic respiration is a key process in biochemistry. The reported number of ATP molecules are produced per glucose molecule ranges from 30 to 36 in different textbooks. Some authors, who write more than one textbook, give different numbers in different books, published in the same year. Some books explain why there is uncertainty in the number, while others do not. Rote learning the number of ATP produced per glucose molecule is counter-productive because there is little understanding. (Changing what students should learn may have implications for the type of questions that can be asked in an examination, but that is a discussion for another occassion.) What is more important is that students develop “an understanding of the nature of scientific inquiry”, to be able “to evaluate and debate scientific arguments and claims”, and “to appreciate the dynamic nature of science knowledge” (quotations from the Australian Curriculum: Science). The fact that different textbooks have reported different estimated numbers of ATP produced per glucose molecule is a great example of how knowledge in science has evolved and continues to evolve in response to new evidence and discoveries. The various estimated numbers demonstrate the strengths and limitations of science as evidence-based conclusions continue to evolve based on new evidence. Instead of focussing on a single number that is the most current estimate of the number of ATP produced per glucose molecule, students should focus on the fact that the downward revision of this number over time is a demonstration of the testable and contestable the nature of science and the processes of science, including chemical science