The Link Reaction "Moving to a new world"

Labeled for reuse link

Excuse the dramatic and nonsensical title.

Now many people might neglect our friend the link reaction, but lucky for you, I am not one of those people. So yay. I guess. 

Let's get started shall we? Well our two friends pyruvate now enter the mitochondria of your cell, fun stuff right? There they decarboxylated (lose a carbon), to form a 2 carbon acetyl group. 

This carbon bonds with O2 to form CO2. This waste gas is released, to wreak havoc on our atmosphere. Also fun stuff. Yeah. Not really... But I digress, the acetyl group is now oxidized. 

Oops, side note. Redox reactions. They are more complex than I'm about to describe them, but for now this is all you have to know. Or all I'm going to tell you. Remember these two words, OIL RIG. Got it? Good. 

Oil stands for: oxidizing is losing

And rig stands for: reduction is gaining. 

Now what do I mean by that? Well oxidizing is losing hydrogens and electrons and gaining oxygen, and reduction is gaining hydrogens and electrons, and you guessed it, losing oxygen. Also important to note, if something is reduced something else was oxidized. In other words, they always happen together. 

Back to the link reaction. The acetyl group is oxidized forming reduced NAD+. And reduced NAD+ is NADH. 

Finally the acetyl group combines with coenzyme A (CoA) to form Acetyl CoA. 

Also, remember this process happens twice, because there are two pyruvate molecules produced for every one molecule of glucose. 

In summary (what is produced in the link reaction) 

No ATP produced 

2 NADH molecules

2 Acetyl CoA

In summary (what have we produced in total thus far)

4 NADH molecules 

2 ATP 

2 Acetyl CoA