This study explores the process and ways through which a teaching strategy such as Predict, Observe and explain (POE) helps students of grade 9 to enhance conceptual understanding of biology (enzymes). Through this strategy a teacher can create an atmosphere of inquiry and critical thinking in the science classroom. This study was conducted in three phases: Pre- intervention, Intervention and Post-intervention by using qualitative research paradigm embedded within action research. In pre- intervention I assessed current knowledge about existing teaching practices and learning atmosphere at research site as well as conceptual understanding and skills of students through observation and pre-test in the chapter (Enzymes) which was already taught by subject teacher. During Intervention stage I played two roles, that of a teacher and of a researcher. As teacher I taught the same chapter (enzymes) to all students of grade 9 of a private school in Karachi, using POE as teaching strategy. During this process emphasis was given to important aspects of POE; prediction, observation and explain and the gradual progress in conceptual understanding of students and skills. The process of learning and the ways which lead to conceptual understanding were also assessed. In Post intervention stage I assessed progress in conceptual understanding. Data were collected by using different methods and tools to ensure better reliability. For example pre-test, observational checklist, field notes, worksheets, reflective diary and post- test. Similarly data were analyzed at two stages: one was ongoing analysis of students’ work and responses while the other was thematic analysis after field work. I found that the students, who had not full understanding about enzymes in the pre- test, showed better and deeper understanding in the post- test. POE helped students in enhancing their concepts through motivation. Students not only became more proficient in science process skills of predictions, observations and explanations but also became competent in applying their learning (previous knowledge) according to the learning situation. I also found that through POE a teacher can identify students’ alternative frame works in biological concepts and rectify these alternative frameworks. I also found that POE based activities not only useful in enhancing conceptual understanding but also useful to enhance informal reasoning skills which can help students to better articulate their concepts with justifications on the basis of scientific grounds and reasons. Results of my research study reveal that teachers’ teaching style and methodology play a vital role in learning; student followed