in bacteria the respiratory enzymes are situtatd in the\tcytoplasm\tcell membrane\tribosomes\tmitochondria

The correct option is 2.
The respiration of oxygen is fundamental to the life of higher animals and plants. The basic respiratory process in the mitochondria of these organisms involves the donation of electrons by low-redox-potential electron donors such as NADH. This is followed by electron transfer through a range of redox cofactors, bound to integral membrane or membrane-associated protein complexes. The process terminates in the reduction of the high-redox-potential electron acceptor, oxygen. The free energy released during this electron-transfer process is used to drive the translocation of protons across the mitochondrial membrane to generate a trans-membrane proton electrochemical gradient or protonmotive force (Δp) that can drive the synthesis of ATP. The respiratory flexibility of the mammalian mitochondrion is rather poor. There is some flexibility at the level of electron input, but none at the level of electron output where cytochrome aa3 oxidase provides the only means of oxygen reduction. In the case of plant mitochondria, a slightly greater degree of respiratory flexibility is encountered with a number of alternative NADH dehydrogenases and two oxidases being apparent. This respiratory flexibility affords plant mitochondria with the capacity to contribute to processes other than the generation of ATP. For example, electron transfer from the alternative NADH dehydrogenase to the alternative oxidase is not coupled to the generation of Δp and instead serves to release energy as heat, which can volatilize insect attractants to aid pollination.