Lecture Notes: Aerobic Cellular Respiration and ATP Production

Introduction

• Discussion on morning routines and energy levels.
• Cells continuously perform processes needing energy (ATP) unlike humans.
• ATP: Adenosine Triphosphate
  • Nucleic acid with three phosphates.
  • Energy currency for cells.

ATP Production in Cells

• All cells (prokaryotic & eukaryotic) must produce ATP.
• Differences in ATP production process based on cell type.

Aerobic Cellular Respiration

• Focus on eukaryotic cells with organelles like nucleus and mitochondria.
• Eukaryotic cells include protists, fungi, animals, and plants.

Importance of Mitochondria

• Central to aerobic respiration process in eukaryotes.

Overview of Aerobic Cellular Respiration Equation

• Reactants on the left; products on the right.
• Similar to photosynthesis but not opposite.
• Glucose as a product in photosynthesis; reactant in respiration.

Fun Fact: Bean Seeds

• Germinating beans rely on stored glucose for ATP until photosynthesis begins.

Glycolysis (Step #1)

• Occurs in cytoplasm; anaerobic process.
• Converts glucose to pyruvate.
• Net yield: 2 pyruvate, 2 ATP, 2 NADH.
• NADH: A coenzyme that transfers electrons.

Intermediate Step

• Pyruvate transported to mitochondria.
• Converted to acetyl CoA, releasing CO2, producing NADH.

Krebs Cycle / Citric Acid Cycle (Step #2)

• Occurs in mitochondrial matrix; aerobic process.
• Produces 2 ATP, 6 NADH, 2 FADH2, and releases CO2.
• FADH2: Coenzyme similar to NADH.

Electron Transport Chain and Chemiosmosis (Step #3)

• Occurs in inner mitochondrial membrane; requires oxygen.
• Electrons from NADH and FADH2 generate a proton gradient.
• ATP synthase enzyme uses gradient to convert ADP to ATP.
• Oxygen final electron acceptor, forming water.
• High ATP yield: Range of 26-34 ATP from this step; total 30-38 ATP.

Variation in ATP Production

• ATP yield varies due to factors like proton gradient.
• Important to understand range rather than memorize specific numbers.

Fermentation: Alternative ATP Production

• Occurs when no oxygen is available, though less efficient.

Importance of ATP Production

• Critical cellular function, impacted by toxins like cyanide.

Mitochondrial Research

• Ongoing research into mitochondrial diseases.