All UK Exam Boards included

Link reaction and Krebs cycle

Download Topic

The pyruvate proceeds to being oxidised to a compound called acetyl coenzyme A upon reaction with coenzyme A which results in the production of yet another NADH and, voila! a carbon dioxide molecule, our first ever CO2; please welcome it graciously…

 

So far we’ve got 2 ATP, 3 NADH and 1 CO2 – not that impressive, onwards and upwards!

 

P.S.: the pyruvate –> acetyl-CoA step isn’t part of glycolysis, (it’s called the link reaction) I just tagged it along to have 3 steps overall rather than 4. Magic numbers and all that.

 

2. The citric acid (Krebs) cycle

The previously produced acetyl-CoA gets oxidised to carbon dioxide, while NAD continues to be reduced to NADH. The CO2 gets eliminated when we exhale, while the NADH is passed onto the next and final step of aerobic respiration.

 

The Krebs cycle is a series of reduction-oxidation reactions (redox reactions) which produce multiple coenzymes. Coenzymes are molecules which assist enzymes in their catalysing activity.

 

 

 

 

 

Sorry! There are no posts.

Sorry! There are no posts.

Your Reviews

I got A* in A-level biology (Cambridge), thanks! I love your videos

Sherif Negm Facebook

Good topic notes and cool videos. I'll definitely recommend it to my students.

Seema Sehgal AQA Examiner and biology teacher on LinkedIn

OFF TOPIC : I just want to say that your website is brilliant, thank you!!

Anonymous YouTube

You explain everything so simply! 

SecretDuck The Student Room

Hi! I have recently finished my first year doing biology at uni and I subscribed to you back when I was doing AQA A levels (glad I don’t live in Wales after watching this vid lol) and you and your website helped me so much. Just wanted to say it’s so nice to see you

Mr Peanutbutter YouTube