Photosynthesis and Cellular Respiration Quiz
Study Sheet
Quiz Date: ________________
Know this information.
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All living things need a source of energy to carry on their life activities.
Food provides the energy living things need to survive.
Photosynthesis:
 During the process of photosynthesis, plants and other organisms use energy from
sunlight to make their own food.
 The food-making process of plants, some protists, and some bacteria is called
photosynthesis.
 Photosynthesis is the process by which plants and some other organisms convert
carbon dioxide and water into oxygen and organic compounds known as sugars.
 Oxygen is a by-product of the process of photosynthesis. Most of the oxygen on our
planet is produced during photosynthesis.
 Glucose is a simple sugar produced during photosynthesis.
 Autotrophs are organisms that can make their own food.
 Heterotrophs cannot make their own food. Heterotrophs depend on plants and other
photosynthetic organisms for a food source, or they eat other organisms that eat
autotrophs.
 The process of photosynthesis is powered by sunlight.
 The sunlight is absorbed by a green pigment in leaves called chlorophyll. (A
pigment is a chemical that absorbs some wave lengths of light and reflects others.)
 Organelles called chloroplasts contain chlorophyll. It is in the chloroplasts that
carbon dioxide and water are converted into glucose and oxygen. (Water vapor is
also produced during photosynthesis.)
 The raw materials of photosynthesis are water and carbon dioxide.
 Water enters the plant through its roots. It moves upward in the stem to the leaves where photosynthesis occurs.
 Carbon dioxide enters the plant through tiny openings in the leaves called stomata
(singular = stoma). Guard cells surrounding the stomata regulate the amount of
carbon dioxide coming into the leaves. (The guard cells also regulate the amount of
water vapor and oxygen that leave the cell as by-products of photosynthesis.)
Cellular Respiration:
 The process by which organisms get energy from food is called cellular respiration.
 During cellular respiration, cells break down simple organic food molecules such as
glucose and release the energy they contain.
 This process is called cellular respiration because it happens in cells. The
mitochondria are the organelles most responsible for cellular respiration.
 The raw materials of cellular respiration are glucose and oxygen.
 The products of cellular respiration are carbon dioxide, water, and energy.
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The energy created by cellular respiration is stored in a molecule called ATP.
Fermentation is a kind of cellular respiration that does not require oxygen.
Fermentation is an anaerobic process. That means it takes place without oxygen.
(Aerobic means “with oxygen.)
Fermentation of yeast results in alcohol as a by-product.
When the human body is involved in strenuous exercise and the lungs cannot provide
the muscles with oxygen fast enough to meet its needs, lactic acid builds up. This is a
type of fermentation. Anaerobic respiration is not as efficient as aerobic respiration.
It produces far less energy.
Comparing Photosynthesis and Cellular Respiration:
 The raw materials of photosynthesis are the products of cellular respiration.
 The raw materials of cellular respiration are the products of photosynthesis.
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These two processes are thought of as opposite processes and complementary because
the raw materials of one are the products of the other. Together, photosynthesis and
cellular respiration form a cycle that keeps the levels of carbon dioxide and oxygen
fairly constant in the atmosphere.