Transcript Chapter 6: Photosynthesis

Chapter 6: Photosynthesis &
Chapter 7: Cellular Respiration
• I. Energy and Living Things
–A. Building Molecules That Store
Energy
• 1. Autotrophs make their own food
by using energy from sunlight or
inorganic substances to build organic
compounds.
• 2. Many autotrophs make food by
the process of photosynthesis.
• B. Breaking Down Food for
Energy
–1. Energy from sunlight flows
through living systems, from
autotrophs to heterotrophs.
–2. Heterotrophs release the
energy in food through the
process of cellular respiration.
• C. Transfer of Energy to ATP
–1. Cellular respiration releases
much of the energy in food to
make ATP, the energy “currency”
inside cells.
–2. Enough energy is released from
ATP to drive most of a cell’s
activities.
• D. ATP Releases Energy
–1. ATP supplies cells with energy
needed for metabolism.
–2. Energy is released upon the
breakdown of ATP to ADP.
H20 + ATP  ADP + P + energy
• II. Photosynthesis
–A. Using the Energy in Sunlight
• 1. The 3 Stages of Photosynthesis
–a. First, energy is captured from
sunlight.
–b. Second, energy is temporarily
stored in ATP and NADPH.
–c. Third, organic compounds are
made using ATP, NADPH, and
carbon dioxide.
• B. Stage One: Absorption of Light Energy
–1. Pigments- such as chlorophyll,
absorb light energy during
photosynthesis.
–2. Production of Oxygen- During
photosynthesis, water molecules are
split to release oxygen by an enzyme
inside structures called thylakoids.
• C. Stage Two: Conversion of Light
Energy
–1. Electron Transport ChainsElectrons excited by light travel
through electron transport chains,
in which ATP and NADPH are
produced.
• D. Stage Three: Storage of Energy
– 1. Calvin Cycle- Through carbon dioxide
fixation, often by the Calvin cycle, carbon
dioxide in the atmosphere is used to make
organic compounds, which store energy.
– 2. Factors that Affect Photosynthesis by the
environmental
• a. the intensity of light
• b. the concentration of carbon dioxide
• c. the temperature
• III. Cellular Respiration
• A. Cellular Energy
–1. The Stages of Cellular
Respiration
•a. There are two stages.
–2. Glycolysis
•a. Is the first stage of cellular
respiration
• B. Stage One: Breakdown of Glucose
– 1. Aerobic and Anaerobic Respiration
• a. The second stage of cellular respiration is either
• 1. aerobic respiration (in the presence of oxygen)
or
• 2. anaerobic respiration (in the absence of
oxygen).
• 3. A large amount of ATP is made during aerobic
respiration.
• 4. NAD+ is recycled during the anaerobic process
of fermentation.
• 2. Glycolysis- Glucose is broken down to pyruvate
during glycolysis, making some ATP.
• C. Stage Two: Production of ATP
–1. Krebs Cycle- is a series of
reactions that produce energystoring molecules during aerobic
respiration.
–2. Electron Transport ChainDuring aerobic respiration, large
amounts of ATP are made in an
electron transport chain.
• D. Fermentation in the Absence of Oxygen
– 1. Fermentation When oxygen is not present,
fermentation follows glycolysis, regenerating NAD+
needed for glycolysis to continue.
– 2. Lactic Acid Fermentation
•
a. Pyruvate is converted to lactate.
– 3. Alcoholic Fermentation- pyruvate is broken
down to ethanol, releasing carbon dioxide.
– 4. Production of ATP although a small amount of
ATP is made during fermentation, most of a cell’s
ATP is made during aerobic respiration.