Video Transcript
The link reaction occurs in between
glycolysis and the Krebs cycle. What is the primary product of the
link reaction?
Cellular respiration is the process
used by cells to release energy from sugars. The general overall equation for
cellular respiration is glucose plus oxygen goes to carbon dioxide plus water. Energy is released in the form of
ATP. The equation given here seems quite
simple, but the actual process is slightly more complicated.
Cellular respiration occurs in four
main stages: glycolysis, the link reaction, the Krebs cycle, and finally oxidative
phosphorylation. We can see that the link reaction
occurs in between glycolysis and the Krebs cycle, so it links them. The products of glycolysis become
the reactants of the link reaction. The name the link reaction is a bit
misleading. It actually refers to a series of
reactions that converts one compound into another. Let’s have a look at the link
reaction in more detail.
First, a three-carbon compound
called pyruvate loses a carbon in the form of carbon dioxide. This converts pyruvate into a
two-carbon compound. Next, this two-carbon compound
donates electrons and a hydrogen ion to the coenzyme NAD plus to form reduced
NAD. Finally, a molecule called coenzyme
A bonds to the two-carbon compound. This newly formed compound is
called acetyl coenzyme A.
So we have our correct answer. The primary product of the link
reaction is acetyl coenzyme A.
