Abstract:Three protein modifiers, butanedione (BTD), N-bromosuccinimide (NBS) and ρ-Chloromercuribenzoic acid (ρCMB), were used to treat cells of a green marine alga, Dunaliella salina. The photosynthetic oxygen evolution and absorption spectra were studied by oxygen electrode and spectrophotomeler. All of the used modifiers inhibited the photosynthetic rate of Dunaliella salina to a certain extent. The inhibition was 14.6% (BTD, 0.21 mmol/L), 21.4% (NBS, 0.02 mmol/L) and 39.7% (ρCMB, 0.1 mmol/L), respectively. A c...