Question

How is the ETC ‘coupled’ to ATP production?

What does an ‘uncoupler’ do?

What is an ROS? How are we protected from them?

Answer 1

The basic mechanism of ATP production is based on chemo osmotic theory. In this a elecrochemical gradient is build across membrane by proton transfer and then this electrochemical gradient is coupled to ATP synthase enzyme that transport 3 hydrogen ion for production of one ATP molecule.

Coupled reaction means that the electron flow is tightly regulated such that each step is perfectly done. But in presence of some chemicals such as that can alter membrane permeability and can cause alternative pathway of proton flow. This alternative path for flow of Proton leads

rapid disruption of electrochemical gradient. This leads to uncoupling of proton flow and ATP production.

2)An uncoupler basically provide an alternative pathway for proton flow.

3)Reactive Oxygen species (ROS) are chemically reactive chemical species containing oxygen. In a biological context, ROS are formed as a natural byproduct of the normal metabolism of oxygen and have important roles in cell signaling and homeostasis. These ROS are capable of cousing cancer,is the cause of ageing process, male infertility etc

Enzyme such as Superoxide dismutase Catalyse reaction that converts superoxide into hydrogen peroxide and Oxygen.Catalase enzyme concentrated in peroxysomes Located next to mitochondria (peroxisome are highly variable in composition)