Through the catabolism of sugars, fats, and proteins
, a two carbon organic product acetate in the form of acetyl-CoA is produced. Acetyl-CoA along with two equivalents of water (H
2
O) are consumed by the citric acid cycle, producing two equivalents of carbon dioxide (CO
2
) and one equivalent of HS-CoA.
How does acetyl CoA enter the citric acid cycle?
Acetyl CoA
transfers its acetyl group to oxaloacetate to form citrate
and begin the citric acid cycle. The release of carbon dioxide is coupled with the reduction of NAD
+
to NADH in the citric acid cycle.
How many acetyl CoA produced in citric acid cycle?
The citric acid cycle goes around twice for each molecule of glucose that enters cellular respiration because there are two pyruvates—and thus,
two acetyl CoA
start text, C, o, A, end texts—made per glucose.
What is produced during the citric acid cycle?
The citric acid cycle is a series of reactions that produces
two carbon dioxide molecules, one GTP/ATP, and reduced forms of NADH and FADH2
.
Where does citric acid cycle formation occur?
In eukaryotic cells, the citric acid cycle occurs
in the matrix of the mitochondrion
.
How is pyruvate converted to acetyl CoA?
A carboxyl group is removed from pyruvate and released as carbon dioxide. The two-carbon molecule from the first step is oxidized, and NAD+ accepts the electrons to form NADH. The oxidized two-carbon molecule, an acetyl group, is attached to Coenzyme A to form acetyl CoA.
How is acetyl CoA formed after glycolysis?
During the breakdown of pyruvate, electrons are transferred to NAD+ to produce NADH, which will be used by the cell to produce ATP. In the final step of the breakdown of pyruvate,
an acetyl group is transferred to Coenzyme A to produce acetyl CoA
.
How is pyruvate converted to acetyl CoA quizlet?
When one molecule of pyruvate enters pyruvate oxidation in the mitochondrial matrix
, it is converted into one molecule of acetyl-CoA when part of the one pyruvate molecule is oxidized and has some that splits into carbon dioxide.
How does the citric acid cycle produce ATP?
The citric acid cycle, where acetyl CoA is modified in the mitochondria to produce energy precursors in preparation for the next step.
Oxidative phosphorylation, the process where electron transport from the energy precursors from the citric acid cycle (step 3) leads to the phosphorylation of ADP
, producing ATP.
Why citric acid cycle is called TCA cycle?
Citric acid is a so-called tricarboxylic acid, containing three carboxyl groups (COOH)
. Hence the Krebs cycle is sometimes referred to as the tricarboxylic acid (TCA) cycle.
Why is the citric acid cycle called a cycle quizlet?
Why is the krebs cycle called a cycle?
because the process starts over and over again
because the citric acid is reused as the 4 carbon compound over and over again.
Is water produced in the citric acid cycle?
The two main products that result from the breakdown of glucose are carbon dioxide and water. Carbon dioxide is produced during pyruvate dehydrogenase and the Krebs cycle.
Water is formed at the end of the electron transport chain where two electrons (hydrogens) are added to oxygen (the final electron acceptor).
Which are formed during one turn of the citric acid cycle quizlet?
A single “turn” of the citric acid cycle will yield:
1 ATP, 3 NADH, and 1 FADH2
.
What energy intermediates are produced in the citric acid cycle?
During what stage are these intermediates produced? Explanation: The citric acid (Krebs) cycle and glycolysis yield high energy intermediates that can then be used to make ATP. Each turn of the citric acid cycle generates
NADH and FADH
2
, and each cycle of glycolysis generates NADH.
What activates the citric acid cycle?
Calcium as a regulator of the citric acid cycle
Therefore,
the signal that stimulates muscle contraction
is also activating the production of the ATP which sustains it, through the citric acid cycle.
Is acetyl CoA an intermediate of TCA cycle?
Although oxaloacetate and acetyl-CoA are impermeable to mitochondrial membranes
, citrate and other intermediates of the cycle are permeable. Certain rodenticides can interrupt the TCA cycle. Several B vitamins are required as cofactors in the TCA cycle.
Which substances generated in the citric acid cycle participate in the ETC?
Coenzymes including
FAD and NAD+
are reduced in the Krebs cycle, which transfers electrons by the electron transport chain with oxygen as the final acceptor. Three NADH+ and one FADH
2
are generated in one cycle which, on entering the electron transport chain, yields 10 ATP.
What is the conversion of pyruvate to acetyl CoA that must occur prior to the citric acid cycle?
Prior to entry into this cycle,
pyruvate must be converted into a 2-carbon acetyl-CoenzymeA (acetyl-CoA) unit
. Figure 15.2. 1: After glycolysis, two 3-carbon pyruvates enter the mitochondria, where they are converted to two 2-carbon acetyl-CoenzymeA (CoA) molecules. Acetyl-CoA then enters the Krebs Cycle.
What happens to the acetyl-CoA that is produced from pyruvate quizlet?
Used by the citric acid cycle as a fuel. Carbon acetyl groups are converted to CO2 and ATP and electrons (carried by NADH and FADH2) create even MORE electrons. The 2-carbon acetyl group from pyruvate is
taken and attached to Coenzyme A
.
What is citric acid cycle quizlet?
citric acid cycle definition. –
a metabolic pathway that converts carbon atoms to CO2 and, in doing so, conserves metabolic free energy that ultimately drives the synthesis of ATP
. – a central pathway whose intermediates are both precursors and products of a large variety of biological molecules.
Where is pyruvate converted to acetyl coenzyme A?
In eukaryotic cells, the pyruvate molecules produced at the end of glycolysis are transported into
the mitochondria
, which are the sites of cellular respiration. There, pyruvate is transformed into an acetyl group that will be picked up and activated by a carrier compound called coenzyme A (CoA).
