Competency in technological pedagogical content knowledge is one of the fundamental standards to become a qualified teacher in 21st century. Teachers are expected to have TPACK with technology integration efficacies in their classroom. This research aims to explain the roles of TPACK and its components on behaviorist and constructivist learning-teaching conceptions. Designed as an explanatory research the current study employs hypotheses explaining cause-result connections amongst independent variables (knowledge of technology, knowledge of pedagogy and content knowledge), mediators (technological content knowledge, pedagogical content knowledge, technological pedagogical knowledge, and technological pedagogical content knowledge) and dependents (behaviorist and constructivist teacher conceptions). One of the structural equation modeling applications benefits from path analysis to uncover these associations. Mediation effects between them are tested through the Sobel tests and bias-corrected bootstrapping confidence interval. The path analyses point out that behaviorist teacher conception is just affected by technology knowledge. They show also that technology and pedagogy knowledge have indirect effects on constructivist teacher conceptions via technological content, pedagogical content, technological pedagogical knowledge, and TPACK. It is found that content knowledge is an agent directly affecting constructivist teacher conceptions. It is suggested that teachers should take part in workshops, projects etc. on TPACK or technology integration.