AP Biology
Mrs. Ward’s Class
UNIT 3 STUDY GUIDE
This unit is 12-16% of the AP Exam. The content on enzymes is the foundation for many concepts we will learn in
this course. If you don’t have a good understanding of the concepts in this unit, you may have significant
challenges in later units.
Chapter 6: An Introduction to Metabolism
Vocabulary:
activation energy
active site
allosteric regulation
anabolic pathway
catabolic pathway
catalyst
chemical energy
coenzyme
cofactor
competitive inhibitor
cooperativity
endergonic reaction
enzyme
enzyme-substrate complex
exergonic reaction
feedback inhibition
free energy
induced fit
metabolic pathway
metabolism
non-competitive inhibitor
substrate
Learning Objectives:
Metabolism, Energy, and Life
 Explain the role of catabolic and anabolic pathways in cellular metabolism.
 Distinguish between exergonic and endergonic reactions.
Enzymes
 Describe the function of enzymes in biological systems.
 Explain how enzyme structure determines enzyme specificity.
 Explain the induced-fit model of enzyme function
 Describe the catalytic cycle of an enzyme.
 Explain how substrate concentration affects the rate of an enzyme-catalyzed reaction.
 Describe the influence of cofactors and coenzymes on enzyme activity.
 Explain why the three-dimensional structure of an enzyme is the key to its activity, and the role that
temperature, pH, and inhibitors play in altering enzyme activity.
The Control of Metabolism
 Explain how metabolic pathways are regulated.
 Describe how allosteric regulators may inhibit or stimulate the activity of an enzyme.
 Explain how feedback inhibition prevents a cell from wasting chemical resources.
 Describe how localization of enzymes within a cell may help order metabolism.
Chapter 7: Cellular Respiration & Fermentation
Vocabulary:
acetyl CoA
aerobic
alcohol fermentation
anaerobic
ATP synthase
cellular respiration
chemiosmosis
citric acid cycle
electron transport chain
FAD/FADH2
fermentation
glycolysis
lactic acid fermentation
NAD+/NADH
oxidation
oxidative phosphorylation
oxidizing agent
redox reaction
reducing agent
reduction
substrate-level phosphorylation
AP Biology
Mrs. Ward’s Class
Learning Objectives:
Principles of Energy Harvest
 Distinguish between fermentation and cellular respiration.
 Write the chemical equation for cellular respiration.
 Explain how ATP is recycled in cells.
 Define oxidation and reduction.
 Explain how redox reactions are involved in energy exchanges.
 Describe the role of NADH and FADH2 in the electron transport chain during respiration.
The Process of Cellular Respiration
 Describe the cellular regions where glycolysis, the Krebs cycle, and the electron transport chain occur.
 Describe how the carbon skeleton of glucose changes as it proceeds through glycolysis.
 Explain why ATP is required for the energy investment phase of glycolysis.
 Identify where substrate-level phosphorylation and the reduction of NAD+ occur in glycolysis.
 Describe where pyruvate is oxidized to acetyl CoA, what molecules are produced, and how this process
links glycolysis to the Krebs cycle.
 Explain how the exergonic "slide" of electrons down the electron transport chain is coupled to the
endergonic production of ATP by chemiosmosis.
 Describe the process of chemiosmosis.
 Explain how membrane structure is related to membrane function in chemiosmosis.
 Summarize the net ATP yield from the oxidation of a glucose molecule by constructing an ATP ledger that
includes coenzyme production during the different stages of glycolysis and cellular respiration.
Related Metabolic Processes
 Explain why fermentation is necessary.
 Compare the fate of pyruvate in alcohol fermentation and lactic acid fermentation.
 Compare the processes of fermentation and cellular respiration.
 Describe evidence that the first prokaryotes produced ATP by glycolysis.
 Describe how food molecules other than glucose can be oxidized to make ATP.
 Explain how glycolysis and the Krebs cycle can contribute to anabolic pathways.
 Explain how ATP production is controlled by the cell and what role the allosteric enzyme,
phosphofructokinase, plays in the process.
Chapter 8: Photosynthesis
Vocabulary:
absorption spectrum
action spectrum
autotroph
Calvin cycle
CAM plant
carbon cycle
carbon fixation
carotenoids
chlorophyll a
chlorophyll b
chloroplast
cyclic electron flow
cyclic photophosphorylation
global warming
glyceraldehyde-3-phosphate
(G3P)
guard cells
light reactions
mesophyll cell
mesophyll
NADP+
noncyclic electron flow
photon
photorespiration
photosynthesis
photosystem I
photosystem II
primary electron acceptor
reaction center
rubisco
stomata
stroma
thylakoid
AP Biology
Mrs. Ward’s Class
Learning Objectives:
Photosynthesis in Nature
 Distinguish between autotrophic and heterotrophic nutrition.
 Describe the structure of chloroplasts and indicate their locations within plant cells. Describe where
most chloroplasts are located in a leaf.
 Explain how chloroplast structure relates to its function.
 Write a summary equation for photosynthesis.
The Pathways of Photosynthesis
 Explain the role of redox reactions in photosynthesis.
 Describe in general the two main stages of photosynthesis.
 Describe the relationship between an action spectrum and an absorption spectrum.
 Explain why the absorption spectrum for chlorophyll differs from the action spectrum for
photosynthesis.
 List the wavelengths of light that are most effective for photosynthesis.
 Explain what happens when chlorophyll or accessory pigments absorb photons.
 List the components of a photosystem and explain their functions.
Science as a Process
 Trace electron flow through photosystems II and I.
 Compare cyclic and noncyclic electron flow and explain the relationship between these components
of the light reactions.
 Describe important differences in chemiosmosis between oxidative phosphorylation in mitochondria
and photophosphorylation in chloroplasts.
 Summarize the carbon-fixing reactions of the Calvin cycle and describe changes that occur in the
carbon skeletons of intermediates.
 Describe the role of ATP and NADPH in the Calvin cycle.
 Describe what happens to rubisco when the O2 concentration is much higher than CO2.
 Describe the major consequences of photorespiration.
 Describe two important photosynthetic adaptations that minimize photorespiration.
 Describe the fate of photosynthetic products.
 Explain how photosynthesis is affected by various environmental factors.
 Explain how photosynthesis interacts with other metabolic pathways.
Chapter 42: Ecosystems & Energy, Concept 42.4
Vocabulary:
biogeochemical cycle
ecosystem
Learning Objectives:
 Describe the carbon cycle and explain the importance of carbon to all living organisms.
 Explain how decomposition affects the rate of nutrient cycling in ecosystems.
 Describe how increased atmospheric concentrations of carbon dioxide could affect Earth.
 Describe how human interference might alter the biosphere.