R E S O U R C E L I B R A R Y A RT I C L E Calvin Cycle Illustration. The Calvin cycle is a process that plants and algae use to turn carbon dioxide from the air into sugar, the food autotrophs need to grow. G R A D E S 6 - 12+ S U B J E C T S Biology, Chemistry C O N T E N T S 1 Image For the complete illustrations with media resources, visit: http://www.nationalgeographic.org/media/calvincycle/ The Calvin cycle is a process that plants and algae use to turn carbon dioxide from the air into sugar, the food autotrophs need to grow. Every living thing on Earth depends on the Calvin cycle. Plants depend on the Calvin cycle for energy and food. Other organisms, including herbivores, also depend on it indirectly because they depend on plants for food. Even organisms that eat other organisms, such as carnivores, depend on the Calvin cycle. Without it, they wouldn't have the food, energy, and nutrients they need to survive. The Calvin cycle has four main steps: carbon fixation, reduction phase, carbohydrate formation, and regeneration phase. Energy to fuel chemical reactions in this sugar-generating process is provided by ATP and NADPH, chemical compounds which contain the energy plants have captured from sunlight. Vocabulary Part of Term Definition Speech air noun layer of gases surrounding Earth. plural (singular: alga) diverse group of aquatic organisms, the largest of which algae noun are seaweeds. (adenosine triphosphate) chemical found in most living cells and used for ATP noun energy. organism that can produce its own food and nutrients from chemicals in autotroph noun the atmosphere, usually through photosynthesis or chemosynthesis. person who studies the properties and reactions of chemicals in living or biochemist noun once-living material. series of reactions that take place during photosynthesis, where carbon Calvin cycle noun dioxide and water from the atmosphere are converted into sugar. carbohydratenoun type of sugar that is an important nutrient for most organisms. greenhouse gas produced by animals during respiration and used by carbon noun plants during photosynthesis. Carbon dioxide is also the byproduct of dioxide burning fossil fuels. carbon method plants use to attach carbon dioxide from the atmosphere to a noun fixation chemical (RuBP) in order to start the process of photosynthesis. carnivore noun organism that eats meat. chemical process that involves a change in atoms, ions, or molecules of the noun reaction substances (reagents) involved. energy noun capacity to do work. material, usually of plant or animal origin, that living organisms use to food noun obtain nutrients. herbivore noun organism that eats mainly plants and other producers. (nicotinamide adenine dinucleotide phosphate) chemical found in most NADPH noun living cells and used for energy. nutrient noun substance an organism needs for energy, growth, and life. organism that produces its own food through photosynthesis and whose plant noun cells have walls. reduction second step in the Calvin cycle of photosynthesis, where energy reacts noun phase with chemicals to create the simple sugar G3P. fourth and final step in the Calvin cycle of photosynthesis, where energy regeneration noun and sugar interact to form the molecule RuBP, allowing the cycle to start phase again. Part of Term Definition Speech type of chemical compound that is sweet-tasting and in some form sugar noun essential to life. Articles & Profiles Nobelprize.org: Melvin Calvin Science Matters @ Berkeley: Melvin Calvin © 1996–2021 National Geographic Society. All rights reserved..