Appropriate media and learning resources can optimize learning innovations in the 21st century. The use of technology has become an efficient alternative in the implementation of learning. This research aims to implement the protein metabolism electronic modules (e-modules) as biochemistry teaching materials to improve students’ critical thinking (CT) skills. This research refers to comparative quantitative nonparametric methods by comparing measurements of CT skills before applying e-modules during the lesson with the height of CT skills after using the e-module. The e-modules include videos, images, animations, links to various primary sources, and formative tests that follow the learning outcomes. As the result, the advancement of CT skills from the final measurements illustrated a reduction in the number of students categorized as bad and poor and an increasing number of students categorized as good and excellent. Furthermore, the skill improvement can also be seen through the Two Tail T-Test, with a tcount of 4.7752, while the ttable value for the Two Tail T-Test of 2.0262. Since tcount > ttable suggests a significant difference between the initial and final measurement scores test, H0 is rejected, and H1 is accepted. This research concludes that there is an increase in students' CT skills after participating in biochemistry learning using this protein metabolism e-module.