The electrons are passed
through a series of chemical reactions
, with a small amount of free energy used at three points to transport hydrogen ions across the membrane. This contributes to the gradient used in chemiosmosis.
What carries electrons in the citric acid cycle?
The citric acid cycle involves eight chemical reactions that produce carbon dioxide, ATP, NADH and FADH2. The
NADH and FADH2
are electron carriers that can be used by the electron transport chain (ETC).
Where does the citric acid cycle and electron transport chain occur?
The citric acid cycle takes place
in the mitochondrial matrix
. Glycolysis takes place in the cytosol, and the electron transport chain involves both the intermembrane space and the inner mitochondrial membrane. Pyruvate from glycolysis is transported into the mitochondrial matrix for the citric acid cycle.
How many electrons are transferred from one acetyl group during the citric acid cycle?
8 electrons
are transferred from the acetyl group to the NAD+ and FAD coenzymes of the citric acid cycle. The citric acid cycle produces 3 NADH and 1 FADH2, and each coenzyme gains two electrons when reduced.
Where does the NAD+ come from in citric acid cycle?
NAD+ becomes NADH
when two electrons and a hydrogen are added to the molecule
. One molecule of glucose can form 10 molecules NADH. NAD+ accepts electrons and hydrogen during the processes of glycolysis, pyruvate oxidation and the citric acid cycle as well as the breakdown of fatty acids.
What is produced during the citric acid cycle quizlet?
The citric acid cycle generates
3 molecules of NADH, 1 molecule of FADH2, and 1 molecule of GTP(ATP) per acetyl-sCoA
that enters the cycle. Thus, in total, from each round of the citric acid cycle approximately 10 molecules of ATP are produced.
What are the steps in the electron transport chain?
- Generation of a proton gradient across the mitochondrial membrane. Proton accumulation occurs in the intermembrane space of mitochondria.
- Reduction of molecular oxygen and formation of water. …
- ATP synthesis by chemiosmosis.
Which of the eight reactions of the citric acid cycle are?
The eight steps of the citric acid cycle are a series of
redox, dehydration, hydration, and decarboxylation
reactions. Each turn of the cycle forms one GTP or ATP as well as three NADH molecules and one FADH2 molecule, which will be used in further steps of cellular respiration to produce ATP for the cell.
What molecules will carry the electrons to the electron transport chain?
The electron transport chain and ATP synthase are embedded in the inner mitochondrial membrane.
NADH and FADH2
made in the citric acid cycle (in the mitochondrial matrix) deposit their electrons into the electron transport chain at complexes I and II, respectively.
Why is the citric acid cycle a cyclic pathway?
Why is the citric acid cycle a cyclic pathway rather than a linear pathway?
It is easier to remove electrons and produce CO2 from compounds with three or more carbon atoms than from a two-carbon compound such as acetyl CoA
.
Where does the electron transport chain occur?
The electron transport chain is a series of four protein complexes that couple redox reactions, creating an electrochemical gradient that leads to the creation of ATP in a complete system named oxidative phosphorylation. It occurs in
mitochondria in both cellular respiration and photosynthesis
.
How many oxidation reactions occur during the citric acid cycle?
There are
four
redox reactions in the Krebs cycle.
When electrons are transferred to oxygen in the final step of the electron transport chain a molecule of is produced?
The process of forming ATP from the electron transport chain is known as oxidative phosphorylation. Electrons carried by NADH + H
+
and FADH
2
are transferred to oxygen via a series of electron carriers, and
ATPs are formed
. Three ATPs are formed from each NADH + H
+
, and two ATPs are formed for each FADH
2
in eukaryotes.
What are the products from one turn of the citric acid cycle?
Overall, one turn of the citric acid cycle releases two carbon dioxide molecules and produces
three NADHstart text, N, A, D, H, end text, one FADH2
start text, F, A, D, H, end text, start subscript, 2, end subscript, and one ATPstart text, A, T, P, end text or GTPstart text, G, T, P, end text.
Which type of reaction occurs when Succinyl CoA is converted to succinate in the citric acid cycle?
Carbohydrate metabolism
The conversion of succinyl-CoA to succinate yields the only high-energy phosphate bond to be formed directly in the course of the cycle. This reaction is an example of a
substrate level phosphorylation
(page 228).
What happens during electron transport?
During electron transport,
energy is used to pump hydrogen ions across the mitochondrial inner membrane, from the matrix into the intermembrane space
. A chemiosmotic gradient causes hydrogen ions to flow back across the mitochondrial membrane into the matrix, through ATP synthase, producing ATP.
What goes into mitochondrial electron transport?
The electron transport chain is a series of electron transporters embedded in the inner mitochondrial membrane that shuttles electrons from
NADH and FADH
2
to molecular oxygen. In the process, protons are pumped from the mitochondrial matrix to the intermembrane space, and oxygen is reduced to form water.
How is citric acid produced?
Citric acid is the most important organic acid produced in tonnage and is extensively used in food and pharmaceutical industries. It is produced mainly by
submerged fermentation using Aspergillus niger or Candida sp. from different sources of carbohydrates, such as molasses and starch based media
.
How many decarboxylation reactions are in the citric acid cycle?
As a result, at
two steps
, decarboxylation occurs in the Krebs cycle.
What are the reactions in the citric acid cycle?
The overall reaction for the citric acid cycle is as follows:
acetyl-CoA + 3 NAD+ + FAD + GDP + P + 2H2O = CoA-SH + 3NADH + FADH2 + 3H+ + GTP + 2CO2
. Many molecules in the citric acid cycle serve as key precursors for other molecules needed by cells.
What is the first reaction of the citric acid cycle?
The first reaction in the citric acid cycle is
binding
.
