An antibiotic, such as penicillin, which modifies cell wall synthesis, tends to be most effective during which phase of bacterial growth in a closed system?

Bacterial growth in a closed system is characterized by four phases: (1) In the initial lag phase, no growth occurs as the organisms adapt to the new environment. (2) In the exponential, or log phase, the organisms grow at the fastest rate and antibiotics that interfere with cell growth or division are most likely to be effective. (3) In the stationary phase, when nutrients have been largely exhausted, organisms tend to stop growing but may remain ble for long periods of time. (4) In the phase of decline, cell deaths increase due to cell starvation or exposure to toxins. Ref: Brooks G.F. (2013). Chapter 1. The Science of Microbiology. In G.F. Brooks (Ed), Jawetz, Melnick, & Adelberg's Medical Microbiology, 26e.