Cellular respiration and metabolism are topics that are reportedly poorly understood by students and judged to be difficult by many teachers. Although these topics may not be required learning areas in some high school biology curricula, a grasp of fundamental concepts of cellular metabolic processes is advantageous for students undertaking (or intending to undertake) college-level studies in any biology-related course. There are three common difficulties in teaching cellular respiration: (1) Students have a wide array of misconceptions which have developed from prior learning experiences; (2) These misconceptions often persist after instruction perhaps due to the students' level of abstract or concrete operational cognition; and (3) These misconceptions often remain intact throughout the undergraduate years despite repeated instruction at successively more advanced levels. Role-play is an effective method of facilitating learning experiences because this technique uses the student's creative and cognitive input at a number of levels. This article is a description of a role-play where students act out some major parts of cell metabolism to gain greater conceptual understanding of glycolysis and the Krebs cycle by "being" a molecule or a key part in a dynamic cellular process. The overall aim of this practical or workshop session is to provide students with a visual image of these processes by using themselves as the molecules within a room "filled" with cytoplasm and containing organelles such as mitochondria. It is believed that through this experience students may become metacognitive about their own misconceptions and relate the actions they have experienced to more traditional descriptions of respiration and the Krebs cycle. By realizing for themselves the dynamic and three-dimensional nature of the molecular processes, it is hoped they can better learn the biochemical details from the textbooks, Web sites, lectures, and tutorials that they encounter. (Contains 1 table.)