How many ATPs are synthesized for every cytoplasmic NADH...

Labs

Want to see this concept in action?

NEW

Explore this concept interactively to see how it behaves as you change inputs.

View Labs

Key Concepts

Glycerophosphate Shuttle

This shuttle is a mechanism by which electrons from cytosolic NADH are transferred to mitochondrial FAD, bypassing the direct entry of NADH into the mitochondrial matrix. By converting the reducing equivalents to FADH2, the shuttle provides a means to oxidize cytosolic NADH, albeit at the cost of a reduced ATP yield due to the lower energy retention in FADH2 compared to NADH.

Electron Transport Chain Coupling

Electrons from reducing agents such as NADH and FADH2 enter the electron transport chain at different points, resulting in distinct proton pumping actions across the mitochondrial inner membrane. Since FADH2 donates electrons downstream of Complex I, its oxidation results in fewer protons being pumped and consequently a lower ATP yield compared to electrons entering as NADH.

ATP Yield Variability in Shuttle Systems

The conversion of cytosolic NADH to mitochondrial FADH2 via the glycerophosphate shuttle leads to a reduction in the number of ATP molecules synthesized per molecule of NADH. This illustrates how the cell’s method of transferring reducing equivalents influences the bioenergetic efficiency of oxidative phosphorylation, with the glycerophosphate shuttle typically supporting the synthesis of approximately 1.5 ATP molecules per cytosolic NADH.

Transcript

Please give Ace some feedback