2.2.7—Heat generation
- Syllabus
- First assessment 2026
- Objective
- 2.2.7
- Level
- SL
Respiration Disperses Some Energy as Heat
Respiration is not 100% efficient: some chemical energy becomes dispersed heat rather than usable chemical energy or biomass.
Heat still exists, so energy is not destroyed, but once dispersed it is unavailable to the organism for growth or transfer as biomass.
A cell uses glucose for movement; part becomes usable chemical energy and part leaves as heat to the surroundings.
Respiration spends part of it on cell work and disperses part as heat.
Heat is transformed and dispersed; it is not energy destroyed.