Chapter_7-CELLULAR RESPIRATION

Cellular Respiration

1. Energy Carrier

  • The biochemical compound that carries energy in all living systems is ATP (Adenosine Triphosphate), which is the primary energy currency of all cells.

2. Requirements for Cellular Respiration

  • Aerobic cellular respiration requires oxygen.

  • Anaerobic cellular respiration does not require oxygen.

3. Equation for Aerobic Cellular Respiration

  • The equation for aerobic cellular respiration:C6H12O6 + O2= C02 + H20 + ATPThis reaction indicates that glucose and oxygen are converted into carbon dioxide, water, and usable energy in the form of ATP.

4. Glycolysis

  • Glycolysis involves the breakdown of glucose. Glucose is broken down into 2 parts of a 3-carbon molecule.

  • Glycolysis occurs in the cytoplasm of both prokaryotic and eukaryotic cells.

  • Inputs: Glucose

  • Outputs: ATP, pyruvate (3-carbon molecule)

5. Aerobic Respiration

  • Aerobic respiration is the process where cells break down glucose to generate energy in the form of ATP in the presence of oxygen.

  • It consists of the Krebs cycle and the electron transport chain (ETC).

  • Inputs: Glucose, Oxygen

  • Outputs: ATP, Carbon dioxide, Water

  • Location: Krebs cycle and ETC

6. Fermentation (Anaerobic Respiration)

  • Fermentation is an anaerobic process, meaning it happens without oxygen.

  • It allows cells to produce ATP when aerobic respiration is not possible.

  • Inputs: Glucose.

  • Outputs: Varies depending on organism (e.g., lactic acid, alcohol, CO2CO_2).

  • Location: Cytoplasm.

7. Purpose of Krebs Cycle and ETC

  • The Krebs cycle is a crucial step in cellular respiration, the process by which cells convert glucose and other nutrients into usable energy in the form of ATP.

  • The electron transport chain generates lots of ATP.

8. Electron Acceptor and Products of ETC

  • The molecule that accepts electrons at the end of the ETC is oxygen, which generates water.

  • Products: ATP, H2OH_2O, NAD+NAD^+, FAD

9. Benefits and Drawbacks of Aerobic and Anaerobic Respiration

  • Aerobic Respiration:

    • Benefits: High energy yield, sustained energy production, important for multicellular organisms, maintains homeostasis of glucose concentration in the body by breaking it down.

    • Drawbacks: Requires oxygen, slower process, produces reactive oxygen species.

  • Anaerobic Respiration:

    • Benefits: Allows ATP production without oxygen.

    • Drawbacks: Cannot make lots of ATP.

10. Cellular Respiration Processes and Equation

  • Aerobic:(Glucose -> Glycolysis -> Pyruvate -> Krebs Cycle -> Electron Transport Chain and Chemiosmosis)

  • Anaerobic:(Glucose -> Glycolysis -> Fermentation)

  • Cellular Respiration Equation: C6H12O6 + 6O2 -> 6CO2 + 6H2O + Energy (ATP)

  • Krebs cycle is also called the Citric Acid Cycle.

11. Events in ETC by Chemiosmosis

  • Movement of Hydrogen ions (H+H^+) through the membrane protein ATP synthase, driven by the concentration gradient (high to low).

  • This process produces lots of ATP by oxidative phosphorylation.

12. ATP Production

  • The body makes ATP in two ways:

    • Substrate-level phosphorylation.

    • Oxidative phosphorylation, which happens in the mitochondria by cellular respiration.

  • Without chemiosmosis, ATP will not be generated, despite the proton gradient.

13. Oxygen Consumption and Metabolic Rate

  • Oxygen consumption can be used as a measure of metabolic rate because oxygen is necessary for cellular respiration, which makes ATP by oxidative phosphorylation. Oxygen is needed for the ETC.

14. Similarities Between Photosynthesis and Respiration

  • Electron Transport Chain.

  • Chemiosmosis.

  • Fermentation.

15. Glycolysis: True or False

  • True: Glycolysis can occur with or without oxygen.

  • False: Glycolysis occurs in the mitochondria.

  • True: Glycolysis is the first step in both aerobic and anaerobic respiration.

  • True: Glycolysis produces 2 ATP, 2 NADH, and 2 pyruvate.

16. Cramps During Exercise

  • Cramps during exercise are caused by fermentation as it produces lactic acid, which is then stored in your muscles, causing cramps and soreness.

17. Source of Carbon Dioxide in Blood

  • Most of the carbon dioxide normally present in human blood comes from cellular respiration, especially the Krebs cycle.

  • When pyruvate becomes acetyl-CoA, it produces carbon dioxide, and the Krebs cycle also produces large amounts of carbon dioxide.

18. Energy Currency of Cells

  • The energy currency used by cells is ATP.

19. Role of NADH & FADH2

  • NADH and FADH2 are electron carrier proteins.

  • They deliver electrons and hydrogen ions into the electron transport chain.

  • Hydrogen and electrons are the most important matter for ATP production.

20. Purpose of Cellular Respiration

  • The purpose of cellular respiration is to break down glucose to make ATP in the mitochondria.

21. Conditions for Anaerobic Respiration

  • Anaerobic respiration (fermentation) occurs under conditions of no oxygen.

22. Energy Yield of Respiration Processes

  • Aerobic cellular respiration with oxygen yields more energy.

  • Aerobic cellular respiration with oxygen produces 36 ATP by chemiosmosis via ATP synthase in the ETC.

23. Products of Anaerobic Respiration

  • Products of anaerobic respiration (fermentation) if the organism is a plant, bacteria, or fungi: Lactic Acid, alcohol, carbon dioxide, and ATP.

24. Location of Krebs Cycle

  • The Krebs/citric acid cycle occurs in the matrix of the mitochondria.

25. Organisms Performing Cellular Respiration

  • All living organisms perform cellular respiration, except viruses (which are not living organisms).

26. First Process in Cells

  • Glycolysis is the first process to happen when food molecules enter into a cell.

27. Next Step if Oxygen is Present

  • Krebs cycle occurs next if oxygen is present in the cell.

28. Chemiosmosis Involves

  • Chemiosmosis involves the movement of hydrogen ions through the membrane protein called ATP synthase by the concentration gradient.

29. Removal from Pyruvate

  • One carbon is removed from pyruvate during its conversion into an acetyl group.

  • This carbon becomes a carbon dioxide molecule, which causes us to breathe out.

30. Location of Glycolysis

  • Glycolysis happens in the cytoplasm.