In this Grade 7 Life Science lesson from Chapter 2, students learn how cells capture and release energy through the processes of photosynthesis and cellular respiration. Students explore how chlorophyll in plant chloroplasts converts sunlight, carbon dioxide, and water into glucose, and how both plant and animal cells release chemical energy stored in glucose to fuel their activities. The lesson also introduces fermentation as an additional pathway for energy release, building students' understanding of how all living cells meet their energy needs.
Section 1
Plants Convert Sunlight Into Chemical Energy
Through photosynthesis, plant cells transform sunlight into glucose using chloroplasts containing chlorophyll. This process combines carbon dioxide and water, releasing oxygen as a waste product.
Section 2
Cells Break Down Glucose to Release Energy
Cellular respiration occurs in mitochondria, where cells use oxygen to break glucose into smaller molecules, releasing energy, carbon dioxide, and water. This powers all cell activities in plants and animals.
Section 3
Muscles Generate Energy Without Oxygen
When oxygen is limited during exercise, muscle cells switch to fermentation, producing lactic acid and less energy. This causes burning sensations in muscles until oxygen returns and helps remove waste products.
Section 4
Organisms Create a Natural Energy Cycle
Photosynthesis and cellular respiration form a cycle where oxygen and carbon dioxide exchange between plants and animals. The products of one process become the starting materials for the other.
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Section 1
Plants Convert Sunlight Into Chemical Energy
Through photosynthesis, plant cells transform sunlight into glucose using chloroplasts containing chlorophyll. This process combines carbon dioxide and water, releasing oxygen as a waste product.
Section 2
Cells Break Down Glucose to Release Energy
Cellular respiration occurs in mitochondria, where cells use oxygen to break glucose into smaller molecules, releasing energy, carbon dioxide, and water. This powers all cell activities in plants and animals.
Section 3
Muscles Generate Energy Without Oxygen
When oxygen is limited during exercise, muscle cells switch to fermentation, producing lactic acid and less energy. This causes burning sensations in muscles until oxygen returns and helps remove waste products.
Section 4
Organisms Create a Natural Energy Cycle
Photosynthesis and cellular respiration form a cycle where oxygen and carbon dioxide exchange between plants and animals. The products of one process become the starting materials for the other.
Book overview
Jump across lessons in the current chapter without opening the full course modal.
Continue this chapter