Our brains use a disproportionately large amount of glucose and oxygen, but in spite of their substantial respiration, they do no visibly obvious work. Its toxicity is generally believed to be due to its inhibition of mitochondrial electron transport, which eventually leads to the death of specific neurons in the brain. Above the columns in the table below are listed various indicators of biological systems. Above each column in the table below are listed different species generated from molecular oxygen. The pK a of an ionizable group depends on the proton concentration of the solution it is in.
Bacteria often release toxic free radicals as a defence against attack by leukocytes.
The inner mitochondrial membrane is composed of predominantly phospholipids. The cholesterol content of inner mitochondrial membrane can vary with temperature. The cardiolipin fraction of the total membrane phospholipid content of red blood cells is higher than the cardiolipin fraction of the total membrane phospholipid content of muscle cells. The pH of a solution depends on the proton concentration. A recently described insecticide is lethal to insects, but again, only in bright sunlight.