Anaerobic

• Q: What is the first step in anaerobic respiration?

  A: The breakdown of glucose to pyruvate in glycolysis.
• Q: How is glucose initially phosphorylated in glycolysis?

  A: Using two molecules of ATP.
• Q: What happens after glucose is split in glycolysis?

  A: It forms two molecules of phosphorylated 3-carbon compounds.
• Q: During anaerobic respiration, what is produced when the 3-carbon compounds are oxidized?

  A: NADH is produced by passing electrons to NAD.
• Q: How many ATP molecules are produced per 3-carbon compound in glycolysis?

  A: Two ATP molecules per 3-carbon compound, resulting in four ATP in total.
• Q: How many ATP molecules are produced per 3-carbon compound in glycolysis?

  A: Two ATP molecules per 3-carbon compound, resulting in four ATP in total.
• Q: What is the net yield of ATP per glucose molecule in anaerobic respiration?

  A: net yield of 2x ATP per glucose molecule.
• Q: What happens to pyruvate in the absence of oxygen?

  A: Pyruvate is converted into lactate by using electrons from NADH.
• Q: Why is the conversion of pyruvate to lactate important in anaerobic respiration?

  A: It regenerates NAD, which is necessary for glycolysis to continue.
• ATP Yield in Anaerobic Respiration

  2 ATP molecules per glucose molecule
• There are two types of anaerobic respiration: fermentation and alcoholic fermentation.
• Alcoholic fermentation produces ethanol as a waste product instead of lactic acid.
• In yeast cells, the breakdown of glucose results in the production of carbon dioxide (CO2) and ethanol (C2H5OH).
• Anaerobic respiration


  A metabolic process that occurs in the absence of oxygen, where the body breaks down glucose to produce energy
• Purpose of anaerobic respiration


  provide energy in the absence of oxygen
• Anaerobic respiration


  • Occurs when the body needs energy quickly, such as during high-intensity exercises or muscle contractions
  • Glucose is broken down into pyruvate, releasing a small amount of ATP (adenosine triphosphate) and NADH
  • Occurs in the cytoplasm of cells, notably in muscle cells and red blood cells
  • Cells switch to anaerobic respiration when they become oxygen-deprived
  • Produces some energy, but not as efficient as aerobic respiration
• ATP yield in anaerobic respiration

  2 ATP molecules per glucose molecule
• Anaerobic respiration process


  1. Glucose is broken down into 2 pyruvate molecules and 2 NADH molecules

  2. Each pyruvate molecule yields 1 ATP molecule through substrate-level phosphorylation

  3. Total ATP yield per glucose molecule is 2 ATP molecules
• Glycolysis Initiation


  Glucose phosphorylated using 2 ATP
• Splitting of Glucose


  Forms two phosphorylated 3-carbon compounds
• Oxidation


  Compounds oxidized, producing NADH
• ATP Production


  Phosphorylated compounds convert ADP to ATP (4 ATP total)
• Net ATP Yield


  2 ATP used initially, net yield of 2 ATP per glucose
• Pyruvate Conversion (Without Oxygen)

  1. Pyruvate converts to lactate

  2. Regenerates NAD for glycolysis continuation
• Limited Energy Yield


  A anaerobic respiration produces limited energy, yielding only 2 ATP molecules per glucose molecule.
• Lactic Acid Buildup


  Anaerobic respiration produces lactic acid as a byproduct, which can lead to acidosis and muscle fatigue.
• Disadvantages of anaerobic respiration↓

  • only 2% efficient
  • (2ATP/Glucose, wherease aerobic is 38ATP/glucose)
  • as lactate dissolves in cytoplasm it forms lactic acid, dropping pH of cell (acidic!!)
  • acidic means there's too many H+ ions , inhibiting the enzymes that catalyse glycolysis, eventually stopping it so less ATP produced