Understanding how antibiotics inhibit bacterial growth is important if we are design better treatment strategies to avoid the evolution of antibiotic resistance. However, there are surprisingly few models that describe the impact of antibiotics on bacterial physiology and growth. We have investigated how the richness of the nutrient medium affects the efficacy of action of ribosome-targeting antibiotics. We find apparently conflicting results: some ribosome targeting antibiotics work better on rich media while others work better on poor media. These results can be explained by a simple mathematical model. I will also describe preliminary results on the dynamical action of these antibiotics.