Table of Contents
- 1 How does NADH get into the mitochondrion?
- 2 How does NADH cross outer mitochondrial membrane?
- 3 What is NADH shuttle?
- 4 How does NADH produced in the cytoplasm get converted to ATP in the mitochondria?
- 5 How do we get NADH from cytosol to mitochondria?
- 6 What process allows electrons from cytoplasmic NADH to enter mitochondria?
- 7 How does Malate enter the mitochondria?
- 8 How do the electron shuttles that bring NADH into the mitochondria function?
How does NADH get into the mitochondrion?
The shuttle that transports NADH into the mitochondrion is termed the malate-aspartate shuttle (Fig. 7-8), since it relies on specific transporters for malate and aspartate in the mitochondrial inner membrane. OAA in the cytosol is reduced to malate, regenerating NAD+ from NADH.
How does NADH cross outer mitochondrial membrane?
Therefore, reducing equivalents (i.e., electrons) from NADH, rather than NADH itself, are carried across mitochondrial membranes by either malate (Mal) or glycerol 3-phosphate (Fig. 36-1), thus allowing for cytoplasmic NAD+ reformation, and for NADH and/or FADH2 utilization in the mitochondrial ETC.
How NADH can cross inner mitochondrial membrane?
Effective transport of nadh into the mitochondria—the malate-aspartate shuttle. Malate is transported into the mitochondria in exchange for α-ketoglutarate. Inside the mitochondria, malate is oxidized by malic dehydrogenase to provide the NADH which is used as a substrate for the electron transport chain.
What is NADH shuttle?
The NADH shuttle system, which transports the substrate for oxidative metabolism directly from the cytosol to the mitochondrial electron transport chain, has been shown to be essential for glucose-induced activation of mitochondrial metabolism and insulin secretion in adult β-cells.
How does NADH produced in the cytoplasm get converted to ATP in the mitochondria?
The process in which ATP is formed as electrons are transferred from NADH and FADH2 to O2 by a series of electron carriers (over 10 redox centers in 4 enzyme complexes). Carried out by respiratory assemblies in the inner membrane of mitochondria. Oxidation of NADH produces 3 ATP. Oxidation of FADH2 produces 2 ATP.
What does NADH do in mitochondria?
At various chemical reactions, the NAD+ picks up an electron from glucose, at which point it becomes NADH. Then NADH, along with another molecule flavin adenine dinucleotide (FADH2) will ultimately transport the electrons to the mitochondria, where the cell can harvest energy stored in the electrons.
How do we get NADH from cytosol to mitochondria?
Although most NADH molecules are produced by TCA cycle inside of mitochondria, those by glycolysis are in cytosol. Mitochondrial inner membrane does not have any direct NADH transport system. Must rely on “shuttle” systems for transporting the reducing equivalents of cytosolic NADH into mitochondria.
What process allows electrons from cytoplasmic NADH to enter mitochondria?
The malate shuttle allows the mitochondria to move electrons from NADH without the consumption of metabolites and it uses two antiporters to transport metabolites and keep balance within the mitochondrial matrix and cytoplasm. The inner ring primary function is not to move electrons but regenerate the metabolites.
How does acetyl CoA enter the mitochondria?
Acetyl-CoA is first made in the mitochondria either by the removal of hydrogen from a molecule pyruvate or by the oxidation of other fatty acids. This is a delicate balancing act. Acetyl-CoA is moved through the mitochondrial membrane, and enters the cytoplasm of the cell, as the molecule citrate.
How does Malate enter the mitochondria?
Malate is transported, via the malate-α-ketoglutarate translocase, to the mitochondrial matrix, where it is oxidized to oxaloacetate, accompanied by the formation of NADH, which, by respiratory chain oxidation, produces three molecules of ATP.
How do the electron shuttles that bring NADH into the mitochondria function?
The mitochondrial shuttles are systems used to transport reducing agents across the inner mitochondrial membrane. NADH as well as NAD+ cannot cross the membrane, but it can reduce another molecule like FAD and [QH2] that can cross the membrane, so that its electrons can reach the electron transport chain.
What happens to the NADH produced in glycolysis why does it need to get into the mitochondria?
NADH is the reduced version of NAD+, an electron carrier. The role of NADH is to carry electrons into the electron transport chain to generate a chemiosmotic gradient that will be used for oxidative phosphorylation.