DCMU is marketed as an algicide and an herbicide. It works byblocking the binding site for plastoquinone on photosystem II.
- If DCMU blocks plastoquinone from binding to photosystem IIthen in what state (oxidized or reduced) will the chlorophyll a ofphotosystem II be stuck? Why?
- Based on your answer above, in what state would plastoquinonebe stuck? Why?
- Considering where DCMU binds, would plants in nature exposed toDCMU be able to produce
ATP and NADPH through the lightreactions? Why or why not?
- If plants exposed to DCMU cannot produce ATP and NADPH throughthe light reactions, how
would this affect thelight-independent reactions?
- DCMU, as an herbicide, will eventually kill plants that areexposed to it. Why is this the case? In
answering this, relate DCMU tophotosynthesis and both DCMU and photosynthesis to cellularrespiration.
