00:01
This question is about the reactions in the citric acid cycle.
00:05
We're asked how many reactions there are and then to name them.
00:09
So i think the easiest way to answer this question is to actually name them first and then count how many steps we have.
00:19
Figure 26 .8 is a great reference for understanding this process and seeing it in more detail than i can write out here for us.
00:27
But we'll just go through a quick summary of what is involved in the citric acid cycle.
00:34
The book has these broken down by steps, so i'm just going to follow that format as we're going through.
00:41
So the first step, acetyl -coa enters the citric acid cycle by combining with oxaloacetate.
01:03
There's a series of reactions that's involved in this, but eventually this will form citrate.
01:14
In the second step, citrate is converted to its isomer called isocitrate.
01:31
In the third step, isocitrate undergoes oxidation and decarboxillation at the same time.
01:40
So we'll put citrate.
02:00
And remember that decarboxylation just means a process that leads to the loss of co2 from a carboxal group.
02:10
This step will have one co2 that is generated and this is one of the co2 molecules that you'll actually read out.
02:24
All right.
02:25
Steps four and five are grouped together in this book...