NADH and FADH2 molecules resulting from the Krebs cycle (by reducing respectively NAD + and Electron and proton carriers (e- and H +), are oxidized in the final reactions of cellular respiration, and the electrons and protons are captured by oxygen, the final acceptor. The flow of electrons along the respiratory chain causes the active transport of protons along the chain through the inner membrane of the mitochondria. Protons return to the mitochondrial matrix by diffusion - chemiosmosis - and at the same time, ADP undergoes oxidative phosphorylation forming ATP. Because of this movement of protons inside the matrix, the ph of the matrix increases.
This type of transport is an example of secondary active transport
Secondary active transport is a form of active transport in
which there is movement of an ion with another molecule across a
transport membrane. This form of transport use the energy stored in the electrochemical
gradient of an ion to drive the movement of another solute such as sucrose
against a concentration.
The biosphere is that part of the earth where living things thrive and live. It is the portion of the planet that can sustain life. The earth has three other spheres:
