Question

Poison	Action
Oligomycin	Binds and blocks the proton channel in ATP synthase
Carbon monoxide	Inhibits cytochrome oxidase
2,4-dinitrophenol (DNP)	Binds protons and moves them down their electrochemical gradient
Rotenone	Blocks electron transfer at NADH dehydrogenase

Which metabolic poison described will affect oxygen production in chloroplasts? (10pts) Why other poisons described do no affect oxygen production in chloroplasts? (12pts) Explain your answers.

Answer 1

Rotenone will affect oxygen production in choroplast because Rotenone works by interfering with the electron transport chain in mitochondria. It inhibits the transfer of electrons from iron-sulfur centers in complex I to ubiquinone. This interferes with NADH during the creation of usable cellular energy (ATP). Complex I is unable to pass off its electron to CoQ, creating a back-up of electrons within the mitochondrial matrix. Cellular oxygen is reduced to the radical, creating reactive oxygen species, which can damage DNA and other components of the mitochondria.

Other doesnot affect because-

Oligomycin- Oligomycin A is an inhibitor of ATP synthase..The inhibition of ATP synthesis by oligomycin A will significantly reduce electron flow through the electron transport chain; however, electron flow is not stopped completely due to a process known as proton leak or mitochondrial uncoupling.

2,4 DNP:-,Dinitrophenol uncouples oxidative phosphorylation, causes release of calcium from mitochondrial stores and prevents calcium re-uptake..

Carbon monoxide:- Carbon monoxide does not poison plants since it is rapidly oxidised to form carbon dioxide which is used for photosynthesis.