Aerobic and Anaerobic Respiration

Aerobic vs anaerobic respiration, lactic acid cramps, and how yeast makes bread rise. Class 7 Science with quiz.

Class 7 ScienceClass 7 / Grade 7Ages 9–12
Lesson
💪 Aerobic and Anaerobic Respiration
Sprint vs jog — two types of respiration!🏃 Aerobic (with O₂)Glucose + O₂→ CO₂ + H₂O + ATPLots of energy (38 ATP)Complete breakdownsustained exercise💨 Anaerobic (no O₂)Glucose (no oxygen)→ lactic acid + ATPLess energy (2 ATP)Causes muscle crampsbrief intense bursts

Respiration can happen in two ways. Aerobic respiration uses oxygen to completely break down glucose, producing large amounts of energy — thirty-eight ATP molecules per glucose. This is the normal mode during resting or moderate exercise. Anaerobic respiration does not use oxygen — it breaks glucose down incompletely, producing far less energy — only two ATP — along with lactic acid. This emergency mode kicks in during intense exercise when oxygen cannot be delivered fast enough.

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