Respiration 7 Science — Revision Notes
Respiration is the process by which organisms release energy from food molecules through oxidation, providing ATP for cellular functions. Both aerobic and
TL;DR: Respiration is the process by which organisms release energy from food molecules through oxidation, providing ATP for cellular functions. Both aerobic…
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Respiration is the process by which organisms release energy from food molecules through oxidation, providing ATP for cellular functions. Both aerobic and
Key Points to Remember
- Respiration is a series of chemical reactions that release energy from organic compounds
- Aerobic respiration requires oxygen and occurs in mitochondria, producing maximum ATP
- Anaerobic respiration occurs without oxygen in the cytoplasm, producing less ATP
- Glucose is the primary substrate for respiration in most organisms
- Glycolysis breaks down glucose into pyruvate, producing 2 ATP molecules
- Krebs cycle occurs in the mitochondrial matrix and releases carbon dioxide and energy
- Electron transport chain in inner mitochondrial membrane produces the majority of ATP
- Fermentation is anaerobic respiration producing lactate or ethanol depending on organism
- Lactic acid fermentation occurs in muscles during intense exercise
- Alcoholic fermentation occurs in yeast and bacteria, producing ethanol and carbon dioxide
- Respiration releases carbon dioxide and water as byproducts
- Respiratory rate increases with exercise, temperature, and metabolic demand
Important Formulas
- Aerobic Respiration: C₆H₁₂O₆ + 6O₂ → 6CO₂ + 6H₂O + Energy (ATP)
- Anaerobic Respiration: C₆H₁₂O₆ → 2C₂H₅OH + 2CO₂ + Energy (less ATP)
Key Terms
- Respiration: Process of breaking down food molecules to release energy in the form of ATP
- Aerobic Respiration: Respiration requiring oxygen, producing maximum ATP energy from glucose
- Anaerobic Respiration: Respiration without oxygen, producing less ATP than aerobic respiration
- Glycolysis: First stage of respiration that breaks glucose into pyruvate
- Krebs Cycle: Cycle occurring in mitochondria that oxidizes pyruvate and releases energy
- Fermentation: Anaerobic process producing lactate or ethanol without complete oxidation
Frequently Asked Questions
What is the difference between aerobic and anaerobic respiration?
Aerobic respiration requires oxygen and produces approximately 38 ATP per glucose molecule. Anaerobic respiration lacks oxygen and produces only 2 ATP, but occurs when oxygen is limited
Why do muscles produce lactic acid during intense exercise?
During intense exercise, muscles demand more ATP than aerobic respiration can supply. Cells switch to anaerobic fermentation, producing lactic acid as a byproduct, which causes muscle fatigue
How is fermentation used in industry?
Fermentation is used in brewing to produce alcohol, in yogurt production for lactic acid, and in bread making where CO₂ from fermentation makes dough rise
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