ATP and Aerobic Cellular Respiration

Introduction

• ATP is the energy currency used by cells, stands for adenosine triphosphate.
• Cells constantly perform processes like active transport that require ATP.
• Both prokaryotic and eukaryotic cells need to produce ATP.

Aerobic Cellular Respiration

• Focuses on ATP production in eukaryotic cells (e.g., protists, fungi, animals, plants).
• Occurs in cells with membrane-bound organelles such as the nucleus and mitochondria.
• Mitochondria play a crucial role.

Overall Equation

• Reactants (inputs) are on the left; products (outputs) are on the right.
• Similar to photosynthesis, but not direct opposites.
• Photosynthesis produces glucose; respiration breaks down glucose to make ATP.

Step-by-Step Process

1. Glycolysis

• Occurs in the cytoplasm; an anaerobic process.
• Converts glucose into pyruvate, yielding 2 ATP and 2 NADH.
• Pyruvate is transported into the mitochondria for further processing.

2. Krebs Cycle (Citric Acid Cycle)

• Occurs in the mitochondrial matrix; considered aerobic.
• Produces 2 ATP, 6 NADH, 2 FADH2, and releases carbon dioxide.
• NADH and FADH2 are coenzymes that assist in electron transfer.

3. Electron Transport Chain and Chemiosmosis

• Occurs in the inner mitochondrial membrane; requires oxygen.
• Electrons from NADH and FADH2 create a proton gradient.
• Protons move through ATP synthase to produce ATP from ADP.
• Oxygen serves as the final electron acceptor, forming water.

ATP Yield

• Varies based on several factors, including proton gradient.
• Electron transport chain and chemiosmosis produce 26-34 ATP per glucose.
• Total ATP yield, including glycolysis and Krebs Cycle, is estimated at 30-38 ATP per glucose.

Alternative Pathways

• In absence of oxygen, some cells use fermentation to produce ATP.
• Fermentation is less efficient than aerobic respiration.

Importance of ATP

• ATP production is essential for cell survival.
• Cyanide can block ATP production by affecting the electron transport chain.
• Research on mitochondrial diseases is crucial and ongoing.

Conclusion

• Understanding ATP production is vital for comprehending cellular processes.
• Encouragement for continued curiosity and research into cellular metabolism.