A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of
the heavier fractions could produce ATP in the light, whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one of the heavier fractions could produce ATP in the light, whereas organelles in the lighter fraction could produce ATP in the dark. The heavier and lighter fractions are most likely to contain, respectively, chloroplasts and mitochondria. chloroplasts and peroxisomes. mitochondria and chloroplasts. mitochondria and peroxisomes. peroxisomes and chloroplasts.
Chloroplasts and mitochondria are the organelles capable of ATP production by photophosphorylation and oxidative phosphorylation respectively. Chloroplasts are the site for photosynthesis. The light reactions of photosynthesis include splitting of the water molecule in presence of sunlight and transfer of electrons from PS-II to PS-I via electron carrier. During electron transport, a proton gradient is created which in turn drives ATP synthesis.
Mitochondria are the site for aerobic stages of cellular respiration. Glycolysis and Kreb's cycle, the first and second stages of cellular respiration produce NADH and FADH2 during the redox reactions. These reducing powers are oxidized by giving their electrons to the terminal electron acceptor, the oxygen molecule.
Electrons from the reducing powers are carried to oxygen molecules via a series of electron carrier proteins embedded in the inner mitochondrial membrane. During electron transport, an electrochemical gradient is created which in turn drives the ATP synthesis.
