Courses
Teacher-curated, self-paced courses. Looking for a guided sequence through a full topic? See Learning Paths.
4 courses
What Photosynthesis Is and Where It Happens
Biology · High School (11–12) · Photosynthesis
FreeCh 10 · 1/4
How did people find out that plants make their own food? Here you follow the early experiments, learn the overall reaction, and look inside the chloroplast. Then you separate the pigments of a leaf and read the absorption and action spectra.
3Lessons11Problems2Python Labs1Question Set1Mock Test
The Light Reactions
Biology · High School (11–12) · Photosynthesis
FreeCh 10 · 2/4
Light is caught by two photosystems, water is split, and electrons run down a chain in a zig-zag called the Z scheme. Here you see how that run builds a proton gradient, and how the gradient makes ATP while NADPH is formed.
3Lessons10Problems2Python Labs1Question Set1Mock Test
The Calvin Cycle, C4 Plants and Limiting Factors
Biology · High School (11–12) · Photosynthesis
FreeCh 10 · 3/4
ATP and NADPH from the light reactions are spent in the stroma to build sugar. Here you count the turns of the Calvin cycle, follow carbon through a maize leaf, see why RuBisCO sometimes makes a costly mistake, and learn which factors set the pace of photosynthesis.
3Lessons10Problems2Python Labs1Question Set1Mock Test
Photosynthesis in Depth: Counting, Comparing and Reading Graphs
Biology · High School (11–12) · Photosynthesis
StandardFirst lesson freeExtra course
Beyond the textbook: a full account of the ATP, NADPH, carbon and photons that photosynthesis spends, a point-by-point comparison of the C3 and C4 pathways, and the reading of limiting-factor graphs and classic experiments. Twelve harder problems and a full timed mock exam.
3Lessons12Problems2Python Labs1Question Set1Mock Test
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Nutrition: How Living Things Get Food
Biology · High School (9–10), General · Nutrition, Digestive System, Photosynthesis
FreeCh 4 · 1/3
Green plants make their own food from light, water and carbon dioxide. Animals and fungi take theirs from others, in different ways. Follow both, and then trace a meal through the human digestive system.
3Lessons12Problems2Python Labs1Question Set1Mock Test