Gen Bio 1 L9: Aerobic and Anaerobic Cellular Respiration

• Respiration: A process by which living organisms convert energy stored in food molecules into a usable form of energy called ATP.
• Aerobic: Respiration which occurs in the presence of oxygen and involves a series of chemical reactions that take place in the mitochondria of cells.
• Glycolysis: The first step of aerobic respiration, when a molecule of glucose is broken down into two molecules of pyruvate.
• Anaerobic Respiration: Respiration occurs in the absence of oxygen and is less efficient compared to aerobic respiration.
• Lactic Acid: Fermentation which occurs in some bacteria and animal cells, including our muscle cells.
• 2 Main Types of Respiration: Aerobic and Anaerobic Respiration
• Aerobic respiration: is the most common and efficient form of respiration in living organisms.
• Aerobic Respiration: occurs in the presence of oxygen and involves a series of chemical reactions that take place in the mitochondria of cells.
• Aerobic Respiration (steps): Glycolysis, Krebs Cycle, Electron Transport Chain
• During glycolysis, a molecule of glucose is broken down into two molecules of pyruvate.
• Glycolysis: this process produces a small amount of ATP and NADH (nicotinamide adenine dinucleotide)
• After glycolysis, the pyruvate molecules enter the mitochondria, where they undergo further breakdown in the Krebs Cycle.
• Krebs Cycle: "Citric Acid Cycle"
• Krebs Cycle: generates more ATP, NADH, and FADH2 (flavin adenine dinucleotide).
• Electron Transport Chain: The NADH and FADH2 molecules produced in the previous steps donate their electrons to this chain, located in the inner mitochondrial membrane.
• Electron Transport Chain: consists of a series of protein complexes that transfer electrons and pump protons across the membrane.
• Electron Transport Chain: The energy released from this process is used to generate a large amount of ATP through a process called oxidative phosphorylation.
• Aerobic Respiration: produces a total of 36-38 ATP molecules per molecule of glucose, making it highly efficient in terms of energy production.
• Aerobic Respiration: the primary mode of respiration in most living organisms.
• Anaerobic respiration: occurs in the absence of oxygen and is less efficient compared to aerobic respiration.
• Anaerobic respiration: It is commonly observed in certain microorganisms, some plants, and animal cells during periods of low oxygen availability.
• 2 Main Types of Anaerobic Respiration: Alcoholic and Lactic Acid Fermentation
• Alcoholic Fermentation: this type of anaerobic respiration occurs in yeast and some bacteria.
• Alcoholic Fermentation: during this, pyruvate molecules produced during glycolysis are converted into ethanol (alcohol) and carbon dioxide.
• Alcoholic Fermentation: This process regenerates NAD+ (nicotinamide adenine dinucleotide) for glycolysis to continue.
• Lactic Acid Fermentation: occurs in some bacteria and animal cells, including our muscle cells.
• Lactic Acid Fermentation: In this process, pyruvate molecules are converted into lactic acid.
• Lactic Acid Fermentation: Like alcoholic fermentation, this fermentation also regenerates NAD+ for glycolysis.
• Anaerobic respiration: produces a small amount of ATP compared to aerobic respiration.
• Alcoholic fermentation: only 2 ATP molecules are produced per molecule of glucose
• Lactic Acid fermentation: produces 2 ATP molecules as well.
• Anaerobic Respiration (example): Yeast cells undergo alcoholic fermentation, producing ethanol and carbon dioxide.
• Anaerobic Respiration (example): Some bacteria, such as those found in yogurt production, also undergo lactic acid fermentation.
• During intense exercise, our muscle cells switch to anaerobic respiration, leading to the buildup of lactic acid and causing muscle fatigue.
• Aerobic Respiration (example): Humans, animals, most plants, and many microorganisms undergo this.
• Aerobic Respiration (example): It is the primary mode of respiration in most living organisms.