CHAPTER 5 Highlights 111
Key Concepts
Study CHAPTER HIGHLIGHTS
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Key Terms
Section 1
photosynthesis (94)
autotroph (94)
heterotroph (95)
cellular respiration (95)Section 2
pigment (98)
chlorophyll (98)
carotenoid (98)
thylakoid (99)
electron transport chain (100)
NADPH(101)
carbon dioxide fixation(102)
Calvin cycle (102)Section 3
aerobic (104)
anaerobic (104)
glycolysis(105)
NADH(105)
Krebs cycle (106)
FADH 2 (107)
fermentation (108)BIOLOGYBIOLOGY
Unit 2, Unit 3—Use Topics 1– 6 in these units to
review the key concepts and terms in this chapter.Energy and Living Things
Energy from sunlight flows through living systems, from
autotrophs to heterotrophs.
Photosynthesis and cellular respiration form a cycle
because one process uses the products of the other.
ATP supplies cells with energy needed for metabolism.Photosynthesis
Photosynthesis has three stages. First, energy is captured
from sunlight. Second, energy is temporarily stored in ATP
and NADPH. Third, organic compounds are made using
ATP, NADPH, and carbon dioxide.
Pigments absorb light energy during photosynthesis.
Electrons excited by light travel through electron transport
chains, in which ATP and NADPH are produced.
Through carbon dioxide fixation, often by the Calvin cycle,
carbon dioxide in the atmosphere is used to make organic
compounds, which store energy.
Photosynthesis is directly affected by environmental factors
such as the intensity of light, the concentration of carbon
dioxide, and temperature.Cellular Respiration
Cellular respiration has two stages. First, glucose is broken
down to pyruvate during glycolysis, making some ATP.
Second, a large amount of ATP is made during aerobic
respiration. When oxygen is not present, NAD+is recycled
during the anaerobic process of fermentation.
The Krebs cycle is a series of reactions that produce
energy-storing molecules during aerobic respiration.
During aerobic respiration, large amounts of ATP are made
in an electron transport chain.
When oxygen is not present, fermentation follows glycolysis,
regenerating NAD+needed for glycolysis to continue.