Aerobic vs Anaerobic Respiration Quiz

Aerobic vs Anaerobic Respiration

• Aerobic respiration uses oxygen, while anaerobic respiration does not.
• Aerobic respiration is common in most plants and animals, including humans, birds, and other mammals.
• Anaerobic respiration occurs in lower plants, microorganisms, and some animal cells. It is crucial for survival in oxygen-deficient environments.

Comparison of Aerobic and Anaerobic Respiration

• Aerobic respiration releases more energy (36-38 ATP molecules) than anaerobic respiration (2 ATP molecules).
• Aerobic respiration occurs in the cytoplasm and mitochondria, while anaerobic respiration occurs primarily in the cytoplasm.
• The reactants for aerobic respiration are glucose and oxygen, while the reactants for anaerobic respiration are glucose and electron acceptors.
• The products of aerobic respiration are carbon dioxide, water, and ATP, while the products of anaerobic respiration are carbon dioxide, ethanol or lactic acid, and ATP.
• Aerobic respiration involves complete combustion of glucose, while anaerobic respiration involves incomplete combustion.

Stages of Cellular Respiration

• Cellular respiration is a process of energy conversion where carbohydrates are broken down into carbon dioxide, water, and energy (ATP).
• It takes place in both the cytosol and mitochondria of cells.
• Cellular respiration is divided into four main stages: glycolysis, transformation of pyruvate, the Krebs cycle, and oxidative phosphorylation.

Glycolysis

• Glycolysis occurs in the cytosol.
• It breaks down a 6-carbon glucose molecule into two 3-carbon pyruvate molecules.
• Glycolysis is the first step in the metabolism of glucose and occurs in both aerobic and anaerobic organisms.

Krebs Cycle

• The Krebs Cycle (citric acid cycle) takes place in the mitochondria.
• It involves a series of eight steps that oxidize pyruvate to carbon dioxide, generating ATP, NADH, FADH2, and other metabolic intermediates.
• The cycle begins with the addition of acetyl-CoA to oxaloacetate, forming citrate.
• The cycle then proceeds through a series of reactions that involve oxidation, decarboxylation, and substrate-level phosphorylation.

Oxidative Phosphorylation

• Oxidative phosphorylation is the final stage of cellular respiration and occurs in the inner mitochondrial membrane.
• It involves the transfer of electrons from NADH and FADH2 to oxygen, generating a proton gradient across the inner mitochondrial membrane.
• The proton gradient drives the synthesis of ATP by the enzyme ATP synthase.
• This process is responsible for the majority of ATP generated during cellular respiration.

Role of Oxygen in Respiration

• Oxygen is the final electron acceptor in the electron transport chain, accepting electrons from NADH and FADH2.
• This allows for the production of ATP as the electrons move through the chain, driving the proton gradient.

Lactate Fermentation

• In the absence of oxygen, pyruvate is reduced to lactate in a process called lactic acid fermentation.
• This occurs in muscle cells during intense exercise and in certain microorganisms.
• Lactate accumulation in muscles contributes to muscle fatigue.

Alcoholic Fermentation

• In alcoholic fermentation, pyruvate is converted anaerobically into ethanol and CO2.
• This process is used in the production of alcoholic beverages, bread, and other fermented products.

Advantages and Disadvantages of Fermentation and Aerobic Respiration

Fermentation

• Advantages:
  • Produces ATP in the absence of oxygen.
  • Can be used to produce useful products such as ethanol and lactic acid.
• Disadvantages:
  • Produces less ATP than aerobic respiration.
  • Can lead to the accumulation of lactic acid or ethanol, which can be harmful in high concentrations.

Aerobic Respiration

• Advantages:
  • Produces significantly more ATP than fermentation.
  • Is efficient in using energy from glucose.
• Disadvantages:
  • Requires oxygen.
  • Can produce harmful reactive oxygen species.