Aaaaaaand I FINALLY freaking understand it now!!!! Your videos should be required lectures for our A&P/ biology/ science classes. Better than any other “teaching” method in my classes. Thank you! 🙏
How in the world did the scientists figure all this stuff out? It's truly marvelous. Thanks for the B-complex heads-up! Maybe I'm missing something here, but are the phosphates lost or depleted in this process?
Super helpful video (as are the others you've done about cellular respiration). Thanks! One question, though. My textbook says that "*after* moving into the mitochondrial matrix, the pyruvic acid (or pyruvate) is converted into a 2-carbon compound called Acetyl coenzyme A (Acetyl CoA)." Most other sources I'm finding say the same. However, if I understand correctly, this video is saying that this happens *before* moving into the mitochondria, and that the pyruvate molecule actually needs CoA to be able to cross the mitochondria membrane. I'm curious about this difference. Thanks.
1. First reaction of the citric acid cycle is the condensation of acetyl-CoA with oxaloacetate to yield citrate, catalvzed by citrate synthase. 2. Citrate is converted to isocitrate by an enzyme aconitase. This conversion takes place in two steps: - Dehvdration to cis-aconitate - Rehydration to isocitrate. 3. Isocitrate undergoes dehydrogenation and decarboxy-lation in the presence of isocitrate dehydrogenase to form a-ketoglutarate. The formation of NADH and liberation of CO, occurs at this stage. 4. Next a-ketoglutarate undergoes oxidative decarboxy-lation, catalyzed by a multi-enzyme complex, a-ketoglutarate dehydrogenase, an a-ketoglutarate dehydrogenase complex requires thiamine pyro-phosphate (TPP), Lipoate, NAD, FAD and coenzyme-A and results in the formation of succinyl-CoA, a high energy compound, this reaction is physiologically irreversible. At this stage, second NADH is produced along with liberation of second CO, molecule. 5. Succinyl-CoA is converted to succinate by the enzyme succinate thiokinase. This reaction is coupled with the phosphorylation of GDP to GTP. This is a substrate level phosphorylation. This GTP is converted to ATP. 6. Succinate is oxidized further by succinate dehydrogenase to fumarate with the production of FADH,. 7. Next, fumarase catalyzes the addition of water to fumarate to give malate. 8. Malate is converted to oxaloacetate by malate dehydro-genase, and requires NAD*. The synthesis of third NADH occurs at this stage. The oxaloacetate is regenerated which can combine with another molecule of acetyl-CoA and continue the cycle.
Thank you for explaining the kreb cycle. I have mercury poisoning and figured out because I had no more citric acid in me my body goes into a metabolic acidosis and citric acid reversed this but now I am needing a lot of sugar to function which explains the glucose process in the krebs cycle.
This is great. Now I can whistle glycolysis (632) and the Krebs cycle (66544444). If I use sharps for CoA then it's (63#2) and (665#44444). You can even interleave them so it's (63#2) (665#44444) (665#44444) and repeat to represent a glycolysis causing two turns of the TCA cycle. The Music of Life!
I am obliged to thank you from the core of my heart for your teaching and efforts. I can't thank you enough but still... Thanks a lot my dearest sir. ❤️🥰
I would like to suggest a small correction in the 3rd reaction where iso-citrate should convert into oxalo succinate before alpha-ketoglutarate dehydrogenase
This reminded me why I left premed, as many of my peers are just graduating as MDs and entering residency i felt a pang of regret switching to accounting
Hi Dr. Mike, Question, If the CoA is used for move carbon molecules around, why is it needed when the Alpha Ketogluterate moves to being a 4 carbon molecule ( Succinyl CoA)? It seems like it is snapped on, and then snapped off again? I don't see it being needed anywhere else in the Kreb Cycle ( other than at the begining when AcetylCoA enters mitochondria)?
I have read various texts and articles on pyruvate's entrance to the mitochondria.... some say the conversion to acetyl-CoA happens in the mitochondial matrix (i think in one of your other videos - either glycolysis or kreb's you mention it "jumping" into the mitochondria), others say it needs to happen in the cytoplasm before (like you do in this video) - do you have any research you can point me towards that supports the need for Acetyl-CoA formation before entering the mitochondria?
Sir I have book in which Isocitrate converts into oxalosuccinate then after into alpha ketoglutarate( both in the presence of Isocitrate dehydrogenase )
I love the video! I just have one question. What about reducing power? When NAD+ turns into NADH shouldn't a hydrogen atom be oxidized so that the NAD+ takes an electron and a neutral hydrogen atom attaches to the NAD+ to make NADH? I was just double-checking to get your response on the subject.
I got a question! In the link reaction we used to take pyruvate into the matrix, so the link reaction actually happens inside thi mitochondria, however you said that acetyl CoA enters to the mitochondria after the link reaction!!which got me confused, I'll appreciate it if someone explains it to me
As a fat adapted human for 10 years (low carb not keto) I’m most interested in free fatty acids and the kreb cycle. Found this on internet. @Fatty acids are oxidized through fatty acid or β-oxidation into two-carbon acetyl CoA molecules, which can then enter the Krebs cycle to generate ATP. If excess acetyl CoA is created and overloads the capacity of the Krebs cycle, the acetyl CoA can be used to synthesize ketone bodies.” Two acetyl COA….. let’s go!
I was burnt out and your video helped me feel passionate about the sciences again. Thank you.
Your arms did it for me.
Are you kidding?
This explanation is so clear and a great level of detail for students - not too little, not too much.
ur the most jacked biology teacher I love it
Aaaaaaand I FINALLY freaking understand it now!!!!
Your videos should be required lectures for our A&P/ biology/ science classes.
Better than any other “teaching” method in my classes. Thank you! 🙏
Studying for MCAT and this video was more helpful than the explanation during my biochem class. Much appreciated.
me too
My mind is completely blown. This is the best explanation of the krebs cycle I've seen. Thank you!
This explanation was so comprehensive and easy to understand that i want to be asked about it in the exam now
Thank you so much Doctor Mike
im from india and it's so crazy how students from all over theh world r relying on yt videos😭😭
Reading is nice and all, but visual diagrams coupled with verbal explanation is nice
Just what i needed back to back! glycolysis and kreb cycle💪🏼🙌🏼
subscribed
I'll come back again 👏👏👏
How in the world did the scientists figure all this stuff out? It's truly marvelous. Thanks for the B-complex heads-up! Maybe I'm missing something here, but are the phosphates lost or depleted in this process?
Coming back to this video for the 1000th time cause i always forget and watch it again
I understood this 18 min video compared to the hour lecture my Professor tried explaining it, you are a life saver
Adding in the carbon diagram changes my understanding of the cycle completely. How simple yet effective!
I'm having an exam tomorrow and I must say this has raised my confidence to a new level
I learned this better in less than 18 minutes than I have in several semesters of college level bio. Ferris Bueller, you're my hero.
the MOST helpful explanation of the the kreb's cycle! The explanation using the carbon atoms made this finally make sense for me! Thank you :)
Super helpful video (as are the others you've done about cellular respiration). Thanks! One question, though. My textbook says that "*after* moving into the mitochondrial matrix, the pyruvic acid (or pyruvate) is converted into a 2-carbon compound called Acetyl coenzyme A (Acetyl CoA)." Most other sources I'm finding say the same. However, if I understand correctly, this video is saying that this happens *before* moving into the mitochondria, and that the pyruvate molecule actually needs CoA to be able to cross the mitochondria membrane. I'm curious about this difference. Thanks.
Best expalantion of the acid citric cycle I have ever seen.
1. First reaction of the citric acid cycle is the condensation of acetyl-CoA with oxaloacetate to yield citrate, catalvzed by citrate synthase.
2. Citrate is converted to isocitrate by an enzyme aconitase. This conversion takes place in two steps:
- Dehvdration to cis-aconitate
- Rehydration to isocitrate.
3. Isocitrate undergoes dehydrogenation and decarboxy-lation in the presence of isocitrate dehydrogenase to form a-ketoglutarate. The formation of NADH and liberation of CO, occurs at this stage.
4. Next a-ketoglutarate undergoes oxidative decarboxy-lation, catalyzed by a multi-enzyme complex, a-ketoglutarate dehydrogenase, an a-ketoglutarate dehydrogenase complex requires thiamine pyro-phosphate (TPP), Lipoate, NAD, FAD and coenzyme-A and results in the formation of succinyl-CoA, a high energy compound, this reaction is physiologically irreversible. At this stage, second NADH is produced along with liberation of second CO, molecule.
5. Succinyl-CoA is converted to succinate by the enzyme succinate thiokinase. This reaction is coupled with the phosphorylation of GDP to GTP. This is a substrate level phosphorylation. This GTP is converted to ATP.
6. Succinate is oxidized further by succinate dehydrogenase to fumarate with the production of FADH,.
7. Next, fumarase catalyzes the addition of water to fumarate to give malate.
8. Malate is converted to oxaloacetate by malate dehydro-genase, and requires NAD*. The synthesis of third NADH occurs at this stage. The oxaloacetate is regenerated which can combine with another molecule of acetyl-CoA and continue the cycle.
"Everyone's favorite...." It wasn't until after I watched this video. Thank You, Dr. Mike! I am inspired to be like you someday
Love that you also included info about how B vitamins fit in and fatty acids/ketones! Thank you!
Thank you so much for being such amazing teachers on here as well as your podcast! Would you consider doing a whole video on the PDH complex?
Thank you for explaining the kreb cycle. I have mercury poisoning and figured out because I had no more citric acid in me my body goes into a metabolic acidosis and citric acid reversed this but now I am needing a lot of sugar to function which explains the glucose process in the krebs cycle.
Your videos are such a big help🥺❤
Great lecture Mike👍Any thoughts on reverse Krebs cycle that takes place in cancer cells ? thanks
THANK YOU SO MUCH FOR MAKING THESE!!!
Your lectures make me so happy, because I am sure that will understand the topic , thank you sir
I am just watching to comprehend everything because today's lecture I was if I am watching news
This is great. Now I can whistle glycolysis (632) and the Krebs cycle (66544444). If I use sharps for CoA then it's (63#2) and (665#44444).
You can even interleave them so it's (63#2) (665#44444) (665#44444) and repeat to represent a glycolysis causing two turns of the TCA cycle. The Music of Life!
every time I watch this it makes more and more sense. Such a great explanation
Thanks sir, ur videos didn't just helped me a lot academically ,it also makes my day!! You're voice just sounds so cheerful & relaxing
I like that you simplified it .................... really clear !
Thank you very much!
Very detailed and informative video, God Bless You
your videos are the best on yt for medical study. kind regards!
All I get is that it’s good to eat eggs. Right? (B vits).
only God can reward you Dr. The best explanation ❤
Thanks as always you make difficult thing sound easy all the way from Zambia Africa salute you Dr mike🎉🎉
Thank you! 😊
I like how he throws in how all this works on the macro scale.
I am obliged to thank you from the core of my heart for your teaching and efforts. I can't thank you enough but still... Thanks a lot my dearest sir. ❤️🥰
Fantastic work!!!! It helped a ton!
Amazing video just made the topic so easy to understand thank you somuch ❤❤😊 God bless you always
Fantastic! Thank you for sharing this complex process is detail. I will return to it later for reference. Subscribed!
I wish you have had a free online MCAT prep course which covers improtant topics
❤ Thanks, can you explain how to retain all needed elements and how to add them to the body
Thank you so much for this doc!!
Thank you! I enjoyed the video very much! ✨
I hope you guys will have more videos about biochemistry!
Dr Mike you're the goat for saving me in ap bio . cheers 🙌
What about the Candle cycle and the use of fat rather than glucose on a Carnivore diet
Your video definitely helped! I have an exam next week, so hopefully I can ace it now lol
Bro I pay 50 for tutorial and I still dont understand. BUT here its for free and now I feel like Im ready for the test tomorrow
Great lecture
4 NADH = 24. ( 2X4)= 8×3=24+ 4(2FADH)+ 2ATP...total 30 + 8 glycolysis = 38
BRILLIANT! Thanks.
This video helped me a lot thank u
wonderful i love your lectures
Another great video. Thanks.
Like a piece of cake. Thanks.
Man I like your videos. They are great
Thanks for this amazing video
is ionic aluminum and arsenic a required trace element in the Krebs cycle?
Well done on the explanation 😊😊😊
thank you doctor mike!
Mike
“ Everyone’s favourite “
I’d strongly disagree.😂😂😂
Best krebs cycle explanation
Thank you
Bro said everyone's favourite
😂😂
Most handsome Biology tutor to ever exist 🍁🌷
I would like to suggest a small correction in the 3rd reaction where iso-citrate should convert into oxalo succinate before alpha-ketoglutarate dehydrogenase
brilliant, just brilliant.
Thank you u real made biochem easy for me 🙏
I appreciate the last bit on ketones
This reminded me why I left premed, as many of my peers are just graduating as MDs and entering residency i felt a pang of regret switching to accounting
wdym
@@anayahhussain7118 The complicated material and memorizing random unrelated facts
Hi Dr. Mike, Question, If the CoA is used for move carbon molecules around, why is it needed when the Alpha Ketogluterate moves to being a 4 carbon molecule ( Succinyl CoA)? It seems like it is snapped on, and then snapped off again? I don't see it being needed anywhere else in the Kreb Cycle ( other than at the begining when AcetylCoA enters mitochondria)?
swear you need to come teach oat my school because idk why they make it so difficult when they could have just said what you said
I have read various texts and articles on pyruvate's entrance to the mitochondria.... some say the conversion to acetyl-CoA happens in the mitochondial matrix (i think in one of your other videos - either glycolysis or kreb's you mention it "jumping" into the mitochondria), others say it needs to happen in the cytoplasm before (like you do in this video) - do you have any research you can point me towards that supports the need for Acetyl-CoA formation before entering the mitochondria?
Sir I have book in which Isocitrate converts into oxalosuccinate then after into alpha ketoglutarate( both in the presence of Isocitrate dehydrogenase )
Needed to mention that there is no requirement for exogenous glucose as we produce all that is needed via gluconeogenesis.
very nice! thank you
What would be the clinical consequences of inhibiting the enzyme iso-citrate Dehydrogenase?
Midterm tomorrow, must learn
I love the video! I just have one question. What about reducing power? When NAD+ turns into NADH shouldn't a hydrogen atom be oxidized so that the NAD+ takes an electron and a neutral hydrogen atom attaches to the NAD+ to make NADH? I was just double-checking to get your response on the subject.
Thank you ❤
How much this guy benching?
Excellent 👍
I always look for my favorite and Versatile Doc. Dr. Mike...
does the anaerobic glycolysis need B vitamins as well to turn Pyruvate into Lactate?
Дякую! Найкраще пояснення Циклу Кребса. Я не лікар, але все зрозуміло. Особливо як кетони використовують клитини мозку...
Thank you sir
Sir can you Explain us the urea cyle
No way this man is soo good😂.
Love your content
Thank you! 😊
Thank you very much sirs
I got a question! In the link reaction we used to take pyruvate into the matrix, so the link reaction actually happens inside thi mitochondria, however you said that acetyl CoA enters to the mitochondria after the link reaction!!which got me confused, I'll appreciate it if someone explains it to me
The ampersand is a notifier
NVM I GET IT NOWW TYSM!!!
Amazing
i tried to understand this process felt boring so left i will try it later again
As a fat adapted human for 10 years (low carb not keto) I’m most interested in free fatty acids and the kreb cycle. Found this on internet.
@Fatty acids are oxidized through fatty acid or β-oxidation into two-carbon acetyl CoA molecules, which can then enter the Krebs cycle to generate ATP. If excess acetyl CoA is created and overloads the capacity of the Krebs cycle, the acetyl CoA can be used to synthesize ketone bodies.”
Two acetyl COA….. let’s go!
Seems like all of these explanations involve glucose, but doesn’t your body burn fat most of the time?
I think my school is a living in a big complication 😢!!!!!!