Krebs cycle / Citric acid cycle / TCA cycle & ATP count Mnemonic series # 9
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Krebs cycle / Citric acid
Krebs cycle / Citric acid cycle / TCA cycle & ATP count Mnemonic series # 9
The citric acid cycle (also known as the Krebs Cycle or TCA cycle/Tricarboxylic Acid Cycle) is actually a part of the much larger process called cellular respiration, the process where your body harvests energy from the food you eat. Yes, t he citric acid cycle has the same citric acid found in oranges and other citrus fruits!
The citric acid cycle is called a cycle because the starting molecule, oxaloacetate (which has 4 carbons), is regenerated at the end of the cycle. Throughout the citric acid cycle, oxaloacetate is progressively transformed into several different molecules (as carbon atoms are added to and removed from it), but at the end of the cycle it always turns back into oxaloacetate to be used again. Energy can be captured from this cycle because several of the steps are energetically favourable. When a step is favoured, it means that the products of the reaction have lower energy than the reactants. The difference in energy between the products and the reactants is the energy that is released when the reaction takes place (see enzyme kinetics). The released energy is captured as the electron shuttles (NAD^\text{+}
+
start superscript, plus, end superscript and FAD) are reduced to NADH and FADH_{2}
2
start subscript, 2, end subscript .
To start the cycle, an enzyme fuses acetyl CoA and oxaloacetate together so that citric acid is formed (a 2-carbon molecule + a 4-carbon molecule = a 6-carbon molecule!). This is the first molecule that is made in the cycle and is where the cycle gets its name. Enzymes then proceed to speed up (or “catalyze”) a sequence of rearrangements that convert the newly made citric acid molecule into a series of slightly different molecules. These enzymes only change the rate that these rearrangements occur, not the outcome.
here the products of Citric acid cycle
Oxaloacetate
citrate
isocitrate
alpha-keto glutarate
succinyl CoA
succinate
fumarate
malate
From one citric acid cycle, the following products are formed:
1 GTP
3 NADH
1 FADH_{2}
2 CO2
The citric acid cycle (also known as the Krebs Cycle or TCA cycle/Tricarboxylic Acid Cycle) is actually a part of the much larger process called cellular respiration, the process where your body harvests energy from the food you eat. Yes, t he citric acid cycle has the same citric acid found in oranges and other citrus fruits!
The citric acid cycle is called a cycle because the starting molecule, oxaloacetate (which has 4 carbons), is regenerated at the end of the cycle. Throughout the citric acid cycle, oxaloacetate is progressively transformed into several different molecules (as carbon atoms are added to and removed from it), but at the end of the cycle it always turns back into oxaloacetate to be used again. Energy can be captured from this cycle because several of the steps are energetically favourable. When a step is favoured, it means that the products of the reaction have lower energy than the reactants. The difference in energy between the products and the reactants is the energy that is released when the reaction takes place (see enzyme kinetics). The released energy is captured as the electron shuttles (NAD^\text{+}
+
start superscript, plus, end superscript and FAD) are reduced to NADH and FADH_{2}
2
start subscript, 2, end subscript .
To start the cycle, an enzyme fuses acetyl CoA and oxaloacetate together so that citric acid is formed (a 2-carbon molecule + a 4-carbon molecule = a 6-carbon molecule!). This is the first molecule that is made in the cycle and is where the cycle gets its name. Enzymes then proceed to speed up (or “catalyze”) a sequence of rearrangements that convert the newly made citric acid molecule into a series of slightly different molecules. These enzymes only change the rate that these rearrangements occur, not the outcome.
here the products of Citric acid cycle
Oxaloacetate
citrate
isocitrate
alpha-keto glutarate
succinyl CoA
succinate
fumarate
malate
From one citric acid cycle, the following products are formed:
1 GTP
3 NADH
1 FADH_{2}
2 CO2
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در تاریخ 1396/06/08 منتشر شده
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