Lecture Notes: ATP and Cellular Respiration

Introduction

• Discussion on morning routines; varying energy levels
• Cells require constant energy for processes such as active transport
• ATP (adenosine triphosphate) is the energy currency of the cell
• ATP is a nucleic acid with three phosphates

Importance of ATP

• All cells need to produce ATP
• ATP production varies between cell types: prokaryotic vs. eukaryotic
• Focus on aerobic cellular respiration in eukaryotic cells, specifically in mitochondria

Aerobic Cellular Respiration

• Goal: Produce ATP
• Equation: Reactants on left, products on right; similar to photosynthesis

Photosynthesis vs. Respiration

• Photosynthesis creates glucose; cellular respiration breaks it down for ATP
• Germinating beans use stored glucose before photosynthesis capability develops

Cellular Respiration Steps

Step 1: Glycolysis

• Location: Cytoplasm
• Anaerobic process (no oxygen required)
• Converts glucose to pyruvate
• Products: 2 pyruvate, 2 ATP, 2 NADH
• NADH: Coenzyme, transfers electrons for ATP production

Intermediate Step

• Pyruvate transported to mitochondrial matrix
• Pyruvate oxidized to acetyl CoA
• Products: 2 acetyl CoA, CO2, 2 NADH

Step 2: Krebs Cycle (Citric Acid Cycle)

• Location: Mitochondrial matrix
• Considered aerobic, reliant on oxygen-related processes
• Products: 2 ATP, 6 NADH, 2 FADH2, CO2
• FADH2: Another coenzyme aiding in electron transfer

Step 3: Electron Transport Chain and Chemiosmosis

• Location: Inner mitochondrial membrane
• Requires oxygen
• Electrons transferred from NADH and FADH2 to protein complexes
• Proton gradient created across the membrane
• ATP synthase uses gradient to convert ADP to ATP
• Oxygen is the final electron acceptor, producing water

ATP Yield

• Variable range for ATP produced per glucose molecule
• Electron transport chain and chemiosmosis: 26-34 ATP
• Total range adding Krebs and glycolysis: 30-38 ATP

Alternative Pathways

• Fermentation: Occurs in absence of oxygen, less efficient
• Cyanide can block electron transport chain, halting ATP production

Mitochondrial Research

• Importance of research on mitochondrial diseases
• Understanding of treatment continues to grow

Conclusion: ATP production is vital for cell survival, and processes like cellular respiration and fermentation are crucial for energy generation.