Talk:MitoPedia: Terms and abbreviations

Summary of first Core Energy Metabolism lecture series

Core Energy Metabolism implies processes such as Respiration and Fermentation, both of which are involved in ATP production.

Respiration is the process of oxidative phosphorylation, where a chemisosmotic potential drives ATP synthesis.

Fermentation is the process of substrate-level phosphorylation, whereby ATP is derived from internally produced electron acceptors without a chemisomotic gradient.

Both processes are functionally related to maintain REDOX balance.

Whereas respiration involving burning of oxygen leads to profound heat production, fermentation is less effective due to lower enthropy.

In humans, in internal cell respiration, electrons are transferred from reduced Carbon substrates to the final electron acceptor oxygen.

Aerobic fermentation can proceed in the presence of oxygen. Negative effects of fermentation are acidification and energy deprivation.

Oxic and anoxic are terms to describe oxygen conditions in an environment.

Aerobic and anaerobic are terms used to refer to cell metabolism.

Chemisomotic coupling is one of the earliest events in single cells, i.e. bacteria, in evolution.

All single cells have a membrane-bound ATP-synthase.

ATP is produced by using gradients, wherby a chemisomotic potential is generated by Na- and proton pumps.

Protons are expelled into the cytosol, then move back into the intermembrane space. ATP is pulled out by ANT.

LEAK vs. SLIP hypothesis

Electron transport can be partially uncoupled, loosely coupled, dyscoupled or uncoupled. Protons are pumped out of the matrix and outside compartment. Where is the LEAK and how does it take place against a gradient? Different hypotheses exist on the nature vs. the quantification of LEAK. Is it dependent on oxygen flux?

Whereas LEAK seems to be a property of the membrane, SLIP seems to be a property of the pump, continuing at high ATP concentrations.

Temperature occurs to influence these properties, as membrane fluidity is affected. Experiments at 25°C favor SLIP - experiments at 37°C favor LEAK.

Sports reserach experiments are done at 22°C, although they rather should be done at 40°C implying high heat production inside myocytes during exercise.