The direct energy source that drives atp synthesis in respiratory oxidative phosphorylation in eukaryotes is: the proton motive force across the inner mitochondrial membrane. How is necrosis potentially threatening to neighbouring cells: lysosomal enzymes released from dying cell can damage neighbouring cells. As part of osmoregulation, the adrenal glands can secrete a chemical messenger to signal the kidneys to increase ion and water reabsorption. Which combination of path / class is the most appropriate: endocrine / mineralocorticoids (ie. aldosterone) Whats the purpose of introns: exons are coding protons, introns do not code, provides the ability to have multiple combination, facilitates alternative splicing.