Intro to Citric Acid Cycle - Video Tutorials & Practice Problems
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Intro to Citric Acid Cycle Concept 1
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Now, the citric acid cycle is also known as the CREB cycle or the TC A cycle. And it's a central stage in energy generation from food. Now, here it oxidizes the acetyl group of acetyl coa. So here this represents our acetyl coa when we say the aceto group is this portion that is in orange. And it does this to produce high energy molecules such as a TPN A DH and FA DH too. We're talking about this. Now, remember we say that this is broken down into four stages. We have our proteins, carbohydrates and lipids undergoing digestion in the first stage. And they're broken down into amino acids, monosaccharide and fatty acids. In the second stage, we then form our aceto code A which then goes into our citric acid cycle or crab cycle for stage three to create N A DH and FA DH two. Now the N A DH and FA DH two are utilized in the etc or electron transport chain to produce energy required for a TP synthesis. So remember in stage three, these are generated and they go directly into the electron transport chain of stage four in order to generate a lot of a TP. Right. So, keep this in mind, these are the basic steps when it comes to food metabolism. And now we're gonna pay a little bit more attention to the creb cycle or citric acid cycle.
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Intro to Citric Acid Cycle Example 1
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Which of the following statements about the citric acid cycle is incorrect. The carbon dioxide produced from the citric acid cycle is a product of oxidation. That is true. Remember we have a seo going into the citric acid cycle, we make N A DH fa DH two. But we also create energy and carbon dioxide biid. The citric acid cycle oxidize the acetyl group of the acetyl coa to produce energy. This is true oxidation reactions in the citric acid cycle produce co enzymes. N ad positive NF ad this is not true. We oxidize our PSEO coa in order to reduce these two to create N A DH plus fa DH two. So this is incorrect. Then finally, the citric acid cycle is part of the common metabolic pathway. Remember the common metabolic pathway is stages three and stage four of our food metabolism. The citric acid being part of stage three means that it is part of the common metabolic pathway. So this is true, right. So here, the only statement that is incorrect would be option C
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Phases of the Citric Acid Cycle Concept 2
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Now, the citric acid cycle consists of multiple steps which can be grouped into three phases. Now, here we're going to say the first phase is our citrate formation here, the acetyl group from the acetyl coa. So we're starting out with the acetyl coa here reacts with R oxo acetate. So reacts with this in order to form our citrate here, this is a cyclic metabolic pathway. So this here is interacting with what's coming into the citric acid cycle in the form of acetyl coa B deals with succinyl coa formation. Here we're gonna have the is summarization, an oxidation reaction that convert our citrate into succinyl succinyl coa. So here's succinyl coa. Now here as a result of this in, in this stage, we have also the production of N A DH plus carbon dioxide. Now going into stage C or the third stage. Here we have oxo acetate regeneration. So here we're gonna say we have the hydrolysis and oxidation reactions convert our succinyl coa back into oxy acetate here. So basically, we're going for Sinoa, we're going towards oxy aetate as a result of this. We're also creating an A DH fa DH two and some A TP in the form of energy. I remember this N A DH and fa DH two later on will go into the etc or electron transport chain to create even more energy in the form of A TP.
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Phases of the Citric Acid Cycle Example 2
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Identify each of the following statements about the citric acid cycle as true or false. So for a, it says phase c of the citric acid cycle includes reactions that regenerate oyo aide. That is true because then it reacts with acetyl coa at the beginning of the citric acid cycle to create citrate. Which leads us to the next statement. The first phase of the citric acid cycle yes. Uses acetyl coa and oxalacetate to produce citrate. This is true. The citric acid cycle relies on reduction reactions to produce high energy molecules. That is not true. It relies on oxidation reactions to produce high energy molecules in the form of N A DH plus fa DH two. And then finally, oxidation reactions in phase C produce CO2. No. In phase C, we're producing an A DH fa DH two as well as A TP. So this would be false, right? So this is how we could describe each of the statements within this given example. Question.
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Problem
Problem
Which one of the following substances is a part of both phases A and C of the citric acid cycle?
A
Succinyl CoA
B
Oxaloacetate
C
Acetyl CoA
D
Citrate
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