Cellular Respiration
Aligned to HS-LS1-7 — Next Generation Science Standards.
What this lesson teaches
Cells break the bonds in glucose and combine it with oxygen, releasing carbon dioxide and water. Rearranging these bonds results in a net transfer of energy the cell captures as ATP.
Worked examples
Example 1
A sprinting runner's muscle cells break down glucose with oxygen; the released energy powers contraction, and the runner exhales the carbon dioxide produced.
Example 2
Cellular respiration is roughly photosynthesis reversed, which is why the two together form a closed loop of matter.
Example 3
Without enough oxygen the cell switches to fermentation, gets far less energy per glucose, and builds up lactate — the burn in a sprint.
Practice questions
- Write the reactants and products of aerobic cellular respiration.
- Illustrate how breaking and reforming bonds results in a net release of usable energy.
- Explain how photosynthesis and respiration are nearly opposite processes that cycle the same atoms.
Watch the lesson
Every lesson comes with a video taught in English and Spanish — the same video the QR code in the printed workbook opens.
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Respiración celular
Las células rompen los enlaces de la glucosa y la combinan con oxígeno, liberando dióxido de carbono y agua. La reorganización de estos enlaces produce una transferencia neta de energía que la célula capta en forma de ATP.
Ejemplo 1: Las células musculares de un corredor a toda velocidad descomponen la glucosa con oxígeno; la energía liberada impulsa la contracción, y el corredor exhala el dióxido de carbono producido.
Ejemplo 2: La respiración celular es más o menos la fotosíntesis al revés, por eso las dos juntas forman un ciclo cerrado de materia.
Ejemplo 3: Sin oxígeno suficiente la célula cambia a fermentación, obtiene mucha menos energía por glucosa y acumula lactato — el ardor de un sprint.
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