Hey everyone. So here we can say that biochemical systems most commonly employ 2 methods to produce energy. Now in the first one, we have oxidation reactions. And they produce energy in the form of electron carriers, so we're talking about the production of NADH and FADH2. If we take a look here, we have step 8 of our citric acid cycle where we have malate being changed into oxaloacetate. Here, we have NAD+. It's going to gain electrons to become NADH, and through the use of our substrate, malate, and our enzyme, Malate dehydrogenase, we create Oxaloacetate. Remember, when we talk about dehydrogenases as enzymes, we're talking about oxidation reactions. Over here, this represents step 6 of our Citric Acid Cycle where we have Succinate being changed into Fumarate. Again, we're using a dehydrogenase, so this is an oxidation that's occurring. In this case though, we have FAD becoming FADH2. Remember, FAD to FADH2 will be utilized in order to create a pi bond. In this case, we created a Pi bond between these two carbons which transforms our succinate into fumarate. Now, next, we're going to say we have what's called cleavage reactions or just simply hydrolysis. We're going to have the cleavage or hydrolysis of high energy bonds to release energy stored in them. A great way to look at this is the cleaving of our phosphate bonds in ATP to release energy. So here we have ATP, we include our water, here it's going to help break one of these bonds, releasing an inorganic phosphate, and in the process, because we're breaking that high energy bond, we're gonna release ATP. So here's the ATP that's released. So just remember, when it comes to these biochemical systems, biochemical reactions, there's mainly 2 major ways to produce energy, either through oxidation reactions or through cleavage/hydrolysis.
Energy Production In Biochemical Pathways - Online Tutor, Practice Problems & Exam Prep
Energy Production In Biochemical Pathways Concept 1
Video transcript
Energy Production In Biochemical Pathways Example 1
Video transcript
Here it says, identify the following biochemical reaction would use energy or produce energy. In this reaction, we have isocitrate plus NAD+. We're using the enzyme isocitrate dehydrogenase. This creates alpha-ketoglutarate, carbon dioxide, NADH plus H+. Now, here, we're going to say that we're using a dehydrogenase. Remember, this is the enzyme of choice for an oxidation reaction. And we're going to say this is an oxidation reaction because we've produced NADH. Remember these NADH, FADH2 productions for these oxidation reactions will make energy, so this is going to produce energy. This particular reaction itself represents reaction 3 or step 3 in the Krebs cycle or citric acid cycle. Okay? So here, because we're using a dehydrogenase, this is an oxidation reaction. We're making NADH which is an electron carrier. This is indicative of a biochemical reaction that's going to produce energy.
Which of the following biochemical reactions would not produce energy?
ATP + H2O → ADP + HOPO32− + H+
6-phosphogluconate + NADP+ → ribulose-5-phosphate + CO2 + NADPH
Pyruvate + NAD+ + HS–CoA → Acetyl CoA + CO2 + NADH
Glucose + ATP → glucose-6-phosphate + ADP + H+