Photosynthesis-Irradiance (PI) response curves constitute a powerful tool for characterizing the photosynthetic properties of microalgae. This paper presents a dynamic model capable of predicting the photosynthesis rate under dynamic light conditions. Fast and slow time-scale processes are coupled using fluorescence data for three different photoacclimation states. The model shows a very good agreement with the available experimental data and the values of the calibrated parameters are consistent with biological evidence. The predicted PI curves exhibit all the expected trends regarding their initial slopes, maximum photosynthesis rates, and photoinhibion effects. By analyzing the effect of different experimental protocols on the PI curve predictions, our results highlight the importance of an accurate description of the protocols used to obtain the experimental data.