在PURE系统中从Pyruvate中再生ATP

Pyruvate is the end product of glycolysis, where glucose is oxidized to pyruvate, simultaneously reducing NAD+ to NADH. Two molecules of ATP are also produced by substrate-level phosphorylation.
In aerobic organisms, pyruvate is metabolized via the citric acid cycle to produce reduced coenzymes NADH and FADH2. These coenzymes are then oxidized in the electron transport chain to produce ATP and, in the process, regenerate the NAD+ and FAD. As seen in some cell types and organisms, fermentation...

So far, glycolysis has cost the cell two ATP molecules and produced two small, three-carbon sugar molecules. These molecules will proceed through the second half of the pathway, and sufficient energy will be extracted to pay back the two ATP molecules used as an initial investment and produce a profit for the cell of two additional ATP molecules and two even higher-energy NADH molecules.
Step 1 - 5: Glycolysis Preparatory Phase
The first phase of glycolysis has 5 steps where the glucose is...

Glycolysis, the Embden-Meyerhof pathway, is a central metabolic pathway involved in glucose catabolism. It is highly conserved across most organisms, reflecting its fundamental role in cellular energy production. This process occurs in the cytoplasm and can function both in the presence and absence of oxygen, making it versatile for various organisms and environmental conditions.Stages of GlycolysisGlycolysis is a ten-step pathway that converts glucose into pyruvate, generating a net gain of...

After glycolysis, the charged pyruvate molecules enter the mitochondria via active transport and undergo three enzymatic reactions. These reactions ensure that pyruvate can enter the next metabolic pathway so that energy stored in the pyruvate molecules can be harnessed by the cells.
First, the enzyme pyruvate dehydrogenase removes the carboxyl group from pyruvate and releases it as carbon dioxide. The stripped molecule is then oxidized and releases electrons, which are then picked up by NAD+...

Cellular respiration produces 30 - 32 ATP per glucose molecule. Although most of the ATP results from oxidative phosphorylation and the electron transport chain (ETC), 4 ATP are gained beforehand (2 from glycolysis and 2 from the citric acid cycle).
The ETC is embedded in the inner mitochondrial membrane and is comprised of four main protein complexes and an ATP synthase. NADH and FADH2 pass electrons to these complexes, which pump protons into the intermembrane space. This distribution of...

ATP is a highly unstable molecule. Unless quickly used to perform work, ATP spontaneously dissociates into ADP and inorganic phosphate (Pi), and the free energy released during this process is lost as heat. The energy released by ATP hydrolysis is used to perform work inside the cell and depends on a strategy called energy coupling. Cells couple the exergonic reaction of ATP hydrolysis with endergonic reactions, allowing them to proceed.
One example of energy coupling using ATP involves a...