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Overview of Glycolysis

• Glycolysis is the process of breaking down glucose to produce energy.

• Initial input: 2 ATP consumed to initiate the process.

Starting with Glucose

• 6-carbon Glucose Structure: Considered as the main substrate.

• ATP Investment:

  • Two ATP molecules are used to add energy to the glucose before splitting it.

  • This step might seem counterintuitive; however, it's crucial for subsequent energy production.

Splitting the Molecule

• The 6-carbon glucose is split into:

  • Two 3-carbon molecules: This transition is essential for further pathways in cellular respiration.

Pyruvate Oxidation

• Occurs if oxygen is present:

  • Key process: Pyruvate oxidation follows glycolysis.

  • Involves the removal of electrons and hydrogen atoms from the pyruvate.

  • Key Outputs:

    • CO2: Two carbon dioxide molecules are released.

    • NADH: Reduced form of NAD+ generated from the process.

    • FADH2: Another electron carrier produced.

    • ATP: One ATP molecule is generated.

Citric Acid Cycle (Krebs Cycle)

• After pyruvate oxidation, the remaining molecule (acetyl CoA) enters the Krebs cycle.

• Main outputs for each glucose comprised of:

  • 6 NADH: Electron carrier for further energy production.

  • 4 CO2: Waste product released.

  • 2 FADH2: Another reduced electron carrier.

  • 2 ATP: Direct energy yield from the cycle.

Regeneration of Oxaloacetate

• Essential for the continuation of the Krebs cycle:

  • Each cycle must regenerate oxaloacetate to keep the process moving.

  • This regeneration allows acetyl CoA (which comes from pyruvate) to continually enter the cycle.

Enzyme Reference: Phosphofructokinase (PFK)

• PFK is an important regulatory enzyme in Glycolysis.

• Plays a significant role in controlling the flow of carbon through the energy production path.

Additional Remarks

• Throughout this metabolic pathway, each step is crucial for transforming glucose into usable cellular energy.