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oxidative phosphorylation and ETC???

so i was studying biology (a level caie) and i totally get the other parts of respiration (glycolysis, link reaction, krebs cycle) but i just cant seem to understand the last part-oxidative phosphorylation and the electron transport chain...

can someone pleeasseee help me out by explaining it in detail so i can understand
Original post by crooler
so i was studying biology (a level caie) and i totally get the other parts of respiration (glycolysis, link reaction, krebs cycle) but i just cant seem to understand the last part-oxidative phosphorylation and the electron transport chain...

can someone pleeasseee help me out by explaining it in detail so i can understand

A book gives you detail... It's better to give you an overview so you can get the general gist of it, and then you can go back to a book and fill in the details.

All those electrons which have been used to reduce NAD/FAD to NADH/FADH2 during glycolysis and the Krebs Cycle were removed for a purpose. These reduced electron carriers pass their electrons on to a series of (enzyme) proteins in the mitochondrial inner membrane - this series of proteins forms a chain called the electron transport chain.

The electrons from NADH/FADH2 are used to reduce the first protein in the chain - the electron carrier is thus re-oxidised and can be used again. The first protein (or complex) then passes the electron on to the next protein in the chain and so on - it is a series of redox reactions. The final protein in the chain transfers the electrons to molecular oxygen to form water - this is why it's called 'aerobic respiration', because oxygen is required.

As well as reducing oxygen to water, the passing of electrons down the chain causes hydrogen ions, H+, to be pumped out of the matrix of the mitochondria into the intermembranal space. When these protons flow back into the matrix through a special enzyme called ATP-ase, ATP is synthesised (technically, it's released). This is the energy-making part of the ETC, and the H+ flow is called the 'chemiosmotic theory'.

To do:

•

Ensure you understand redox fully, including the definition of 'reduction' meaning the addition of hydrogen and 'oxidation' the removal of hydrogen.

•

Look at the different complexes (proteins) of the ETC, and the carriers which shuttle electrons between them. Which proteins use metal ions, and what metal ions are they?

•

Look at the chemiosmotic theory in more detail, and how the ATPase acts as a 'molecular motor'.

Reply 2
Original post by Reality Check
A book gives you detail... It's better to give you an overview so you can get the general gist of it, and then you can go back to a book and fill in the details.

All those electrons which have been used to reduce NAD/FAD to NADH/FADH2 during glycolysis and the Krebs Cycle were removed for a purpose. These reduced electron carriers pass their electrons on to a series of (enzyme) proteins in the mitochondrial inner membrane - this series of proteins forms a chain called the electron transport chain.

The electrons from NADH/FADH2 are used to reduce the first protein in the chain - the electron carrier is thus re-oxidised and can be used again. The first protein (or complex) then passes the electron on to the next protein in the chain and so on - it is a series of redox reactions. The final protein in the chain transfers the electrons to molecular oxygen to form water - this is why it's called 'aerobic respiration', because oxygen is required.

As well as reducing oxygen to water, the passing of electrons down the chain causes hydrogen ions, H+, to be pumped out of the matrix of the mitochondria into the intermembranal space. When these protons flow back into the matrix through a special enzyme called ATP-ase, ATP is synthesised (technically, it's released). This is the energy-making part of the ETC, and the H+ flow is called the 'chemiosmotic theory'.

To do:

•

Ensure you understand redox fully, including the definition of 'reduction' meaning the addition of hydrogen and 'oxidation' the removal of hydrogen.

•

Look at the different complexes (proteins) of the ETC, and the carriers which shuttle electrons between them. Which proteins use metal ions, and what metal ions are they?

•

Look at the chemiosmotic theory in more detail, and how the ATPase acts as a 'molecular motor'.


oh..
thank you so muchh!!!!!!! i really appreciate it!!!!
Original post by crooler
oh..
thank you so muchh!!!!!!! i really appreciate it!!!!

You're welcome. :smile: Does that help? Does it make sense? Anything else you need clarification on?
Reply 4
Original post by Reality Check
You're welcome. :smile: Does that help? Does it make sense? Anything else you need clarification on?

yeahhh it toally does help and it does makes total sense
and no, i think i got it from here

thank you so so much thoo!!!!! this really helped a lot!!!!
Original post by crooler
yeahhh it toally does help and it does makes total sense
and no, i think i got it from here

thank you so so much thoo!!!!! this really helped a lot!!!!

Great :smile:

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