Question

Describe the oxidative phosphorylation/electron chain. Be sure to include all components and its location.

Answer 1

The oxidative phosphorylation is a continues series of proteins and organic molecules found in the inner membrane of the mitochondria. The electrons are passed from one member of the transport chain to another in a manner of redox reactions. The amount of energy released in these reactions is captured in the form of a   proton gradient, which is then used to make ATP in a process called chemiosmosis. Together, the electron transport chain and chemiosmosis make up oxidative phosphorylation.

The defferent steps involved in the oxidative phosphorylation are the following

• Delivery of electrons by NADH and FADH_22​
• Electron transfer and proton pumping
• Splitting of oxygen to form water
• Gradient-driven synthesis of ATP

Let us take a look in detail the process take place in each of the steps

• Delivery of electrons by NADH and FADH_22​ :-

In this step reduced electron carriers (NADH and FADH_22​start subscript, 2, end subscript) from other steps of cellular respiration transfer their electrons to molecules near the beginning of the transport chain. In the process, they turn back into NAD^++start superscript, plus, end superscript and FAD, which can be reused in other steps of cellular respiration.

• Electron transfer and proton pumping :-

As electrons are passed down the chain, they move from a higher to a lower energy level, releasing energy. Some of the energy is used to pump H^++start superscript, plus, end superscript ions, moving them out of the matrix and into the intermembrane space. This pumping establishes an electrochemical gradient.

• Splitting of oxygen to form water :-

At the end of the electron transport chain, electrons are transferred to molecular oxygen, which splits in half and takes up H^++start superscript, plus, end superscript to form water.

• Gradient-driven synthesis of ATP:-

​​​​​​​    As H^++start superscript, plus, end superscript ions flow down their gradient and back into the matrix, they pass through an enzyme called ATP synthase, which harnesses the flow of protons to synthesize ATP

​​​​​​​

Electron Transport Chain Intermembrane space H* * À Cytc H 20000 XXXXX) i 200000 III non IV IMMUNO NADH FADH2 FAD +2H NAD + H+ 2H+ + 1120, H20 Mitochondrial matrix Inner mitochondrial membrane