Análisis de la evolución del modelo de proteína en los libros de texto de ESO y Bachillerato españoles.

In this work we have analysed the contents of textbooks of Biology and Geology since 7th Grade to 12th Grade, regarding the evolution about the model of protein. We have used 20 textbooks of wide distribution in Spain highschools. During analysing we have made some partial models that gather the elements taken into account in each level. Considering the textbook contents in different categories, the model grows to get a complex model of protein in the 12th Grade. We have observed that students could have a more or less complete model of protein if the textbook is one or another in the lower levels, because not every textbook is just showing the curricular contents, but they also introduce some aspects they will learn in next levels. That allows the student to have a context for the model they are making, contributing to the system thinking.