CELL RESPIRATION
THE KREBS CYCLE
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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acetyl CoA combines with the four carbon compound to create a six carbon compound
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A four carbon compound is transformed and ready to accept another acetyl CoA
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CO2 is released from a five carbon compound to form a four carbon compound
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CO2 is released from a six carbon compound to form a five carbon compound
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Detailed explanation-1: -In the first step of the cycle, acetyl CoAstart text, C, o, A, end text combines with a four-carbon acceptor molecule, oxaloacetate, to form a six-carbon molecule called citrate.
Detailed explanation-2: -Citric acid or citrate is a 6 carbon molecule that is produced when acetyl-CoA joins with a 4 carbon molecule called oxaloacetate to enter the Krebs cycle. For this reason the Krebs cycle is often referred to as the citric acid cycle.
Detailed explanation-3: -The Krebs cycle itself actually begins when acetyl-CoA combines with a four-carbon molecule called OAA (oxaloacetate) (see Figure above). This produces citric acid, which has six carbonatoms.
Detailed explanation-4: -Krebs cycle or TCA cycle takes place in the matrix of mitochondria under aerobic condition. Step 1: The first step is the condensation of acetyl CoA with 4-carbon compound oxaloacetate to form 6C citrate, coenzyme A is released. The reaction is catalysed by citrate synthase.
Detailed explanation-5: -Products and Functions of the Krebs Cycle For one cycle, two molecules of carbon, three molecules of NADH, one molecule of FADH2 and one molecule of ATP or GTP are produced. Each glucose molecule produces two molecules of acetyl CoA, enough for two cycles.