PMID: 7320Jul 9, 1976

Factors affecting the ADP/O ratio in isolated chloroplasts

Biochimica Et Biophysica Acta
S P Robinson, J T Wiskich


(1) The effect of gradual disruption of the outer membrane of intact chloroplasts on CO2 fixation, electron transport and phosphorylation was investigated. The results suggested that whilst ferricyanide and substrate amounts of ADP enter intact chloroplasts only very slowly, methyl viologen rapidly penetrates the outer membrane. (2) Preparatwons of intact pea chloroplasts had an ATP-consuming reaction which resulted in decreased ADP/O ratios when noncyclic electron transport was measured after disruption of the outer membrane. The ATP-consuming reaction was removed into the supernatant after washing the disrupted chloroplasts. The resulting washed chloroplasts gave ADP/O ratios of 1.5-1.6 for ferricyanide and 1.9-2.0 for methyl viologen. (3) Preparations of intact spinach chloroplasts had lower activity of the ATP-consuming reaction and gave similar ADP/O ratios to washed pea chloroplasts. The ADP/O ratios of spinach chloroplasts did not alter significantly after washing. (4) An investigation of the effect of various assay conditions on the ADP/O ratio showed that the phosphate concentration was critical in obtaining optimal values for ADP/O ratio. Decreasing the phosphate concentration below 10 mM decreased the ADP/O ratio sig...Continue Reading


Jan 1, 1987·Toxicon : Official Journal of the International Society on Toxinology·K A SantariusH Haddad
Mar 1, 1980·Plant Physiology·R E Slovacek, G Hind
Jan 1, 1978·Progress in Biophysics and Molecular Biology·B Halliwell

Related Concepts

Magnesium ADP
Plasma Membrane
Hydrogen-Ion Concentration
Oxaloacetic Acids
Oxidative Phosphorylation
Oxygen Consumption
Dark Reactions of Photosynthesis

Trending Feeds


Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Systemic Juvenile Idiopathic Arthritis

Systemic juvenile idiopathic arthritis is a rare rheumatic disease that affects children. Symptoms include joint pain, but also fevers and skin rashes. Here is the latest on this disease.

Chromatin Regulation and Circadian Clocks

The circadian clock plays an important role in regulating transcriptional dynamics through changes in chromatin folding and remodelling. Discover the latest research on Chromatin Regulation and Circadian Clocks here.

Central Pontine Myelinolysis

Central Pontine Myelinolysis is a neurologic disorder caused most frequently by rapid correction of hyponatremia and is characterized by demyelination that affects the central portion of the base of the pons. Here is the latest research on this disease.

Myocardial Stunning

Myocardial stunning is a mechanical dysfunction that persists after reperfusion of previously ischemic tissue in the absence of irreversible damage including myocardial necrosis. Here is the latest research.

Pontocerebellar Hypoplasia

Pontocerebellar hypoplasias are a group of neurodegenerative autosomal recessive disorders with prenatal onset, atrophy or hypoplasia of the cerebellum, hypoplasia of the ventral pons, microcephaly, variable neocortical atrophy and severe mental and motor impairments. Here is the latest research on pontocerebellar hypoplasia.

Cell Atlas Along the Gut-Brain Axis

Profiling cells along the gut-brain axis at the single cell level will provide unique information for each cell type, a three-dimensional map of how cell types work together to form tissues, and insights into how changes in the map underlie health and disease of the GI system and its crosstalk with the brain. Disocver the latest research on single cell analysis of the gut-brain axis here.

Chronic Traumatic Encephalopathy

Chronic Traumatic Encephalopathy (CTE) is a progressive degenerative disease that occurs in individuals that suffer repetitive brain trauma. Discover the latest research on traumatic encephalopathy here.