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Photosynthesis. Chapter 8. What is energy?. the ability to do work. Autotrophs and heterotrophs. Plants and some other types of organisms are able to use light energy from the sun to produce food .
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Photosynthesis Chapter 8
What is energy? • the ability to do work
Autotrophs and heterotrophs • Plants and some other types of organisms are able to use light energy from the sun to produce food. - autotroph (producer): organisms such as plants, which use the sun to make their own food through photosynthesis - heterotroph (consumer): other organisms, such as animals, that cannot use the sun’s energy directly and must eat other organisms for food
Chemical Energy and ATP • Energy comes in many forms, including light, heat, and electricity • Energy can also be stored in chemical compounds!
Adenosine triphosphate (ATP) • ATP is the chemical compound that living things use to store up energy • made up of: - adenine (N containing compound) - ribose (5 C sugar) - 3 phosphate groups
Adenosine diphosphate (ADP) • “Used” ATP • contains: - adenine (N containing compound) - ribose (5 C sugar) - 2 phosphate groups 2
ADP vs. ATP • Cells release the energy in ATP by removing a phosphate group and turning it into ADP. Cells can “re-charge” the ADP molecules by reconnecting the phosphate group through respiration.
ATP • cells use ATP for active transport and movement
ATP and Glucose • Cells must get energy from Carbohydrates to recharge the ATP • a single molecule of glucose (sugar) stores more that 90X the chemical energy of one ATP!
Photosynthesis vs. chemosynthesis • photosynthesis: plants use the energy of sunlight to convert water and carbon dioxide into oxygen and high energy carbohydrates such as sugars and starches • chemosynthesis: a similar process to photosynthesis, but it uses heat and sulfur compounds instead of sunlight. Found in some bacteria, especially deep in the ocean near volcanic vents.
The Photosynthesis Equation reactants products • MEMORIZE THIS!
Light and Pigments • Plants use a pigment called chlorophyll to trap the light. This is what gives them their green color. • pigments: light absorbing molecules found in plants that gather the sun’s energy
Light and Pigments • Chlorophyll is not the only pigment • Carotenoids: plants also contain red, yellow, and orange pigments that absorb other wavelengths of light. We see these pigments in fall leaves
Inside a Chloroplast • photosynthesis takes place inside a chloroplast
Inside a Chloroplast • chloroplasts contain thylakoids, a sac-like photosynthetic membrane • thylakoids contain pigments & proteins to capture the energy in sunlight • thylakoids are arranged in stacks called grana (singular: granum) • the gel-like matrix that surrounds the grana is called the stroma
Inside a Chloroplast • photosynthesis is divided into two stages: 1. light-dependent: reaction that requires light. It releases Oxygen into the air. 2. Calvin Cycle: Does not require light. It creates the carbohydrates molecules
Light-Dependent Reactions • Part One of Photosynthesis: light dependent reactions use light to produce O2 gas and create a small amount of ATP
The Calvin Cycle • Part Two of Photosynthesis is the Calvin Cycle. It does not require light. • Plants use the energy from the ATP made in the light reactions to build sugars that can be stored for a long time • In photosynthesis, 6 CO2 molecules are used to produce 1 6–carbon sugar molecule (C6H12O6)
Factors Affecting Photosynthesis • availability of water: too little water will slow or stop photosynthesis • temperature: optimum (most photosynthesis occurs) temperatures between 0C and 35C • intensity of light: more light, more photosynthesis
Question 1 • Which of the following are autotrophs? a. impalas b. plants c. leopards d. mushrooms
Question 2 • One of the principal compounds that living things use to store energy isa. DNA b. ATPc. H2Od. CO2
Question 3 • In addition to light and chlorophyll, photosynthesis requires a. water and oxygenb. water and sugarsc. oxygen and carbon dioxided. water and carbon dioxide
Question 4 • The leaves of a plant appear green because chlorophyll a. reflects blue lightb. absorbs blue lightc. does not absorb green lightd. absorbs green light
Question 5 • The products of photosynthesis are a. sugars and oxygenb. sugars and carbon dioxidec. water and carbon dioxided. hydrogen and oxygen
Question 6 • Which organelle contains chlorophyll? a. b. c. d.
Question 7 • The first process in the light-dependent reactions of photosynthesis is a. light absorptionb. electron transportc. oxygen productiond. ATP formation
Question 8 • Which substance from the light-dependent reactions of photosynthesis is a source of energy for the Calvin cycle?a. ADP b. ATP c. H2O d. pyruvic acid
Question 9 • The light-independent reactions of photosynthesis are also known as the a. Calvin cycleb. Priestley cyclec. Ingenhousz cycled. van Helmont cycle
Question 10 • Which equation best summarizes the process of photosynthesis? a. b. c. d.