"

Chapter 6 Summary

Key Takeaways

  • Cellular respiration: An aerobic process that systematically extracts energy from glucose through redox reactions, ultimately producing ATP. This process occurs in distinct stages—glycolysis, the citric acid cycle, and the electron transport chain—each taking place in specific cellular locations, primarily the cytosol and mitochondria.
  • Aerobic Respiration: Cellular respiration systematically extracts energy from glucose in three stages—glycolysis, the citric acid cycle, and the electron transport chain (ETC)—to produce ATP. Glycolysis splits glucose into two pyruvate molecules, yielding a net gain of two ATP and generating NADH. The citric acid cycle further processes pyruvate, releasing carbon dioxide and producing ATP, NADH, and FADH₂. The ETC then transfers electrons from NADH and FADH₂, ultimately producing the majority of ATP through oxidative phosphorylation.
  • Fermentation: Anaerobic respiration allows organisms to generate ATP without oxygen by relying on glycolysis and alternative pathways, such as fermentation, to regenerate NAD+ for continued ATP production. Different organisms utilize lactic acid fermentation, alcohol fermentation, or unique prokaryotic pathways to sustain energy production in oxygen-limited environments.

OpenAI. (2025). ChatGPT. [Large language model]. https://chat.openai.com/chat
Prompt: Summarize the following content into three key takeaways.

Flash Cards

Text Description
  1. Cellular respiration: Process cells use to convert glucose and oxygen into energy (ATP), producing carbon dioxide and water as byproducts
  2. High-energy electrons: Electrons carrying significant energy, often used in cellular processes like the electron transport chain
  3. Redox reactions: Reduction-oxidation reactions; Chemical reactions involving electron transfers, where oxidation (loss of electrons) and reduction (gain of electrons) occur simultaneously
  4. Oxidation: Substance loses electrons during a chemical reaction
  5. Reduction: Substance gains electrons during chemical reaction
  6. Aerobic process: Metabolic process requiring oxygen to generate ATP efficiently (e.g., aerobic cellular respiration)
  7. Glycolysis: Converts glucose into pyruvate; Stage I of cellular respiration
  8. Transition reaction: Converts pyruvate to acetyl-CoA before the citric acid cycle
  9. Citric acid cycle: Converts acetyl coA to CO2; Stage II of cellular respiration
  10. Electron transport chain: Series of proteins in the inner mitochondrial membrane that transfer electrons from NADH and FADH₂ to oxygen, producing ATP; Stage III of cellular respiration
  11. Electrochemical gradient: A gradient created by differences in charge and chemical concentration across a membrane, driving ion movement essential for ATP production
  12. Oxidative phosphorylation: The process of producing ATP using energy from electrons transferred through the electron transport chain
  13. Anaerobic respiration: A form of cellular respiration that occurs without oxygen, producing energy by breaking down glucose through pathways like fermentation.
  14. Fermentation: Anaerobic process that allows cells to produce energy from glucose without using oxygen
  15. Lactic acid fermentation: Form of anaerobic respiration that produces lactic acid; Used by muscle cells during intense exercise and by certain bacteria
  16. Alcohol fermentation: Form of anaerobic respiration that produces ethanol and carbon dioxide; Used by yeast and some bacteria
  17. What is the main function of cellular respiration? To produce ATP for cellular work
  18. Equation for cellular respiration: C6H12O6 + 6O2 → 6CO2 + 6H2O + Chemical Energy (in ATP)
  19. Stages of cellular respiration: Glycolysis, Citric Acid Cycle, Electron Transport Chain
  20. Location of cellular respiration: Cytosol (glycolysis), mitochondrial matrix (citric acid cycle), inner mitochondrial membrane (ETC)
  21. Reactants and products of glycolysis: Reactants: Glucose, NAD+, ATP, ADP. Products: Pyruvate, NADH, ADP, ATP (net gain of 2 ATP)
  22. Reactants and products of transition reaction: Reactants: Pyruvate, NAD+, coenzyme A, Products: Acetyl coA, CO2, NADH
  23. Where is most of the energy from glucose stored after the citric acid cycle? Stored in high-energy electrons transported by electron carriers (NADH, FADH2)
  24. Reactants and products of citric acid cycle: Reactants: Acetic acid, NAD+, FAD, ADP,  Products: Carbon dioxide, NADH, FADH2, ATP
  25. Reactants and products of electron transport chain: Reactants: NADH, FADH2, ADP, O2, Products: NAD+, FAD, ATP, H2O
  26. Which stage of cellular respiration produces the most ATP?  Electron transport chain
  27. What is the source of potential energy that drives the production of ATP in the ETC? Electrochemical gradient; Concentration gradient of H+ across the inner membrane of a mitochondrion
  28. Enzyme that creates ATP by adding a phosphate group to ADP as hydrogen ions flow through it: ATP synthase
  29. Max energy yield from 1 glucose in cellular respiration? 38 ATP
  30. Two main types of fermentation: Lactic acid fermentation and Alcohol fermentation
  31. Energy yield from 1 glucose in anaerobic respiration? 2 ATP
  32. How many ATP are produced in each stage of cellular respiration?Glycolysis – 2, Transition Reaction – 0, Citric Acid Cycle – 2, Electron Transport Chain – max 34
  33. Why is oxygen needed in cellular respiration? Acts as final electron acceptor; Pulls electrons out of the electron transport chain, forming water
  34. Which stage of cellular respiration occurs in fermentation? Glycolysis

OpenAI. (2025). ChatGPT. [Large language model]. https://chat.openai.com/chat
Prompt: Can you give me brief summaries of these key terms.

License

Icon for the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License

Biology Essentials 1 Copyright © 2025 by Kari Moreland is licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License, except where otherwise noted.

Share This Book