AP BIO 3.4-3.7 EXAM QUESTIONS
AND ANSWERS
What is the first law of thermodynamics? - Correct Answers -energy can be transferred
and transformed, but it cannot be created or destroyed
What is the second law of thermodynamics? - Correct Answers -every energy transfer
or transformation increases the entropy of the universe
How is order (entropy) maintained in a system? - Correct Answers -by an input of
energy
How are cellular processes powered? - Correct Answers -by ATP
What is an endergonic reaction? - Correct Answers -rxn with net intake of energy
What is an exergonic reaction? - Correct Answers -rxn with net release of energy
What is energy coupling? - Correct Answers -using an exergonic reaction to initiate an
endergonic
What happens if an organism has a loss of energy or energy flow? - Correct Answers -it
dies
Why does the cell undergo the step-wise function to control energy release through
cellular respiration? - Correct Answers -it allows the cell to capture more energy, more
efficiently
How does the proton concentration affect the pH of the area? - Correct Answers -it
makes it more acidic (lowers it)
Identify two differences between the electron transport chain in prokaryotes and
eukaryotes - Correct Answers -prokaryotes have it in the plasma membrane, eukaryotes
have it in the cristae; in prokaryotes H+ is pumped out of the cell, in eukaryotes it's
pumped into the intermembrane space or the thylakoid space
What is chemiosmosis? - Correct Answers -movement of ions down their
electrochemical gradient
, In a metabolic pathway, how does the product of one reaction relate to the reactants of
the subsequent reaction? - Correct Answers -the products of one rxn become the
substrates of the next
Where does the energy that fuels photosynthesis come from? - Correct Answers -the
sun
What organism first evolved photosynthesis? - Correct Answers -cyanobacteria
Identify one piece of evidence that supports oxygenation to atmosphere from
cyanobacteria - Correct Answers -as cyanobacteria populations increased, atmospheric
oxygen levels increased
What are the light-dependent reactions? - Correct Answers -reactions that use light
energy to drive an ETC which creates ATP and NADPH
Where do the light-dependent reactions take place? - Correct Answers -thylakoid
How is ATP synthesized in the light-dependent reactions? - Correct Answers -the fall of
electrons in the ETC is used to pump hydrogen ions and create a concentration
gradient; this movement of ions back across the membrane through ATP synthase
make ATP
How is NADPH synthesized in the light-dependent reactions? - Correct Answers -high
energy electrons from the ETC bond to NADP+
What is chlorophyll? - Correct Answers -a pigment
How does chlorophyll aid in energy capture? - Correct Answers -it captures the sun's
light energy
Where is chlorophyll located? - Correct Answers -in photosystems in the thylakoid
membrane
What happens to the electrons after absorbing energy from light? - Correct Answers -
they become excited and jump to a primary acceptor
How is the photosystem organized to aid in energy capture? - Correct Answers -an
electron is surrounded by chlorophyll which becomes excited by light energy; when the
chlorophyll is excited, the electron is excited, causing it to jump to a primary acceptor
How is the thylakoid membrane organized to aid in energy capture? - Correct Answers -
it has a lot of surface area which allows for more photosystems which contain
chlorophyll
AND ANSWERS
What is the first law of thermodynamics? - Correct Answers -energy can be transferred
and transformed, but it cannot be created or destroyed
What is the second law of thermodynamics? - Correct Answers -every energy transfer
or transformation increases the entropy of the universe
How is order (entropy) maintained in a system? - Correct Answers -by an input of
energy
How are cellular processes powered? - Correct Answers -by ATP
What is an endergonic reaction? - Correct Answers -rxn with net intake of energy
What is an exergonic reaction? - Correct Answers -rxn with net release of energy
What is energy coupling? - Correct Answers -using an exergonic reaction to initiate an
endergonic
What happens if an organism has a loss of energy or energy flow? - Correct Answers -it
dies
Why does the cell undergo the step-wise function to control energy release through
cellular respiration? - Correct Answers -it allows the cell to capture more energy, more
efficiently
How does the proton concentration affect the pH of the area? - Correct Answers -it
makes it more acidic (lowers it)
Identify two differences between the electron transport chain in prokaryotes and
eukaryotes - Correct Answers -prokaryotes have it in the plasma membrane, eukaryotes
have it in the cristae; in prokaryotes H+ is pumped out of the cell, in eukaryotes it's
pumped into the intermembrane space or the thylakoid space
What is chemiosmosis? - Correct Answers -movement of ions down their
electrochemical gradient
, In a metabolic pathway, how does the product of one reaction relate to the reactants of
the subsequent reaction? - Correct Answers -the products of one rxn become the
substrates of the next
Where does the energy that fuels photosynthesis come from? - Correct Answers -the
sun
What organism first evolved photosynthesis? - Correct Answers -cyanobacteria
Identify one piece of evidence that supports oxygenation to atmosphere from
cyanobacteria - Correct Answers -as cyanobacteria populations increased, atmospheric
oxygen levels increased
What are the light-dependent reactions? - Correct Answers -reactions that use light
energy to drive an ETC which creates ATP and NADPH
Where do the light-dependent reactions take place? - Correct Answers -thylakoid
How is ATP synthesized in the light-dependent reactions? - Correct Answers -the fall of
electrons in the ETC is used to pump hydrogen ions and create a concentration
gradient; this movement of ions back across the membrane through ATP synthase
make ATP
How is NADPH synthesized in the light-dependent reactions? - Correct Answers -high
energy electrons from the ETC bond to NADP+
What is chlorophyll? - Correct Answers -a pigment
How does chlorophyll aid in energy capture? - Correct Answers -it captures the sun's
light energy
Where is chlorophyll located? - Correct Answers -in photosystems in the thylakoid
membrane
What happens to the electrons after absorbing energy from light? - Correct Answers -
they become excited and jump to a primary acceptor
How is the photosystem organized to aid in energy capture? - Correct Answers -an
electron is surrounded by chlorophyll which becomes excited by light energy; when the
chlorophyll is excited, the electron is excited, causing it to jump to a primary acceptor
How is the thylakoid membrane organized to aid in energy capture? - Correct Answers -
it has a lot of surface area which allows for more photosystems which contain
chlorophyll
