ESSENTIAL CELL BIOLOGY CHAPTER
#14 EXAM QUESTIONS WITH VERIFIED
ANSWERS
Cristae - ANSWER-A series of infoldings that make up the inner mitochondrial
membrane. These worlds greatly increase the surface area of the membrane.
Chlorophyll - ANSWER-Light-absorbing green pigment that plays a central part in
photosynthesis.
Respiratory Enzyme Complex - ANSWER-Set of proteins in the inner mitochondrial
membrane that facilitates that transfer of high-energy electrons from NADH to water
while pumping protons into the inter membrane space.
NADH Dehydrogenase Complex - ANSWER-The first respiratory complex in the ETC
that accepts electrons from NADH in the form of a hydride ion which is then converted
into a proton and two high-energy electrons.
Cytochrome c Oxidase - ANSWER-Protein complex that serves as the final electron
carrier in the respiratory chain; removes electrons from cytochrome c and passes them
to O2 to produce H2O.
Electrochemical Gradient - ANSWER-Driving force that determines which way an ion
will move across a membrane; consists of a combined influence of the ion's
concentration gradient and the membrane potential.
Redox Reaction - ANSWER-A reaction in which electrons are transferred from one
chemical species to another. An oxidation-reduction reaction.
Redox Pair - ANSWER-Two molecules that can be interconverted by the gain or loss of
an electron; for example, NADH and NAD+.
Redox Potential - ANSWER-A measure of the tendency of a given redox pair to donate
or accept electrons.
Quinone - ANSWER-Small, lipid-soluble, mobile electron carrier molecules found in the
respiratory and photosynthetic electron-transport chains.
Iron-Sulfur Center - ANSWER-Metal complex found in electron carriers that operate
early in the electron-transport chain; has a relatively weak affinity for electrons.
Cytochrome - ANSWER-Membrane-bound, colored, heme-containing protein that
transfers electrons during cellular respiration and photosynthesis.
, Cytochrome c - ANSWER-A small protein that accepts electrons from the cytochrome c
reductase complex and transfers them to the cytochrome c oxidase complex, has a
redox potential of +230 mV.
Photosynthesis - ANSWER-The process by which plants, algae and some bacteria use
the energy of sunlight to drive the synthesis of organic molecules from carbon dioxide
and water.
Chloroplast - ANSWER-Specialized organelle in algae and plats that contains
chlorophyll and serves as the site in which photosynthesis takes place.
Carbon Fixation - ANSWER-Process by which green plants and other photosynthetic
organisms incorporate carbon atoms from atmospheric carbon dioxide into sugars. The
second stage of photosynthesis.
Stroma - ANSWER-In a chloroplast, the large interior space that contains the enzymes
needed to incorporate CO2 into sugars during the carbon-fixation stage of
photosynthesis; equivalent to the matrix of mitochondria.
Thylakoid - ANSWER-In a chloroplast, the flattened dislike sac whose membranes
contain the proteins and pigments that convert light energy into chemical energy during
photosynthesis. They are arranged in stacks called grana.
Thylakoid Space - ANSWER-The space inside each thylakoid that is connected with
that of other thylakoids.
Light Reactions - ANSWER-In photosynthesis, the set of reactions that converts the
energy of sunlight into chemical energy in the form of ATP and NADPH.
Dark Reactions - ANSWER-In photosynthesis, the set of reactions that produce sugars
from CO2; these reactions, also called carbon fixation, can occur in the absence of
sunlight.
Glyceraldehyde 3-Phosphate - ANSWER-A three carbon sugar that is exported to the
cytosol where it is then used to produce sucrose and a large number of other organic
molecules in the leaves of a plant.
Photosystem - ANSWER-Large multi protein complex containing chlorophyll that
captures light energy and converts it into chemical energy; consists of a set of antenna
complexes and a reaction center.
Antenna Complex - ANSWER-In chloroplasts and photosynthetic bacteria, the part of
the membrane-bound photosystem that captures energy from sunlight; contains an
array of proteins that bind hundreds of chlorophyll molecules and other photosensitive
pigments.
#14 EXAM QUESTIONS WITH VERIFIED
ANSWERS
Cristae - ANSWER-A series of infoldings that make up the inner mitochondrial
membrane. These worlds greatly increase the surface area of the membrane.
Chlorophyll - ANSWER-Light-absorbing green pigment that plays a central part in
photosynthesis.
Respiratory Enzyme Complex - ANSWER-Set of proteins in the inner mitochondrial
membrane that facilitates that transfer of high-energy electrons from NADH to water
while pumping protons into the inter membrane space.
NADH Dehydrogenase Complex - ANSWER-The first respiratory complex in the ETC
that accepts electrons from NADH in the form of a hydride ion which is then converted
into a proton and two high-energy electrons.
Cytochrome c Oxidase - ANSWER-Protein complex that serves as the final electron
carrier in the respiratory chain; removes electrons from cytochrome c and passes them
to O2 to produce H2O.
Electrochemical Gradient - ANSWER-Driving force that determines which way an ion
will move across a membrane; consists of a combined influence of the ion's
concentration gradient and the membrane potential.
Redox Reaction - ANSWER-A reaction in which electrons are transferred from one
chemical species to another. An oxidation-reduction reaction.
Redox Pair - ANSWER-Two molecules that can be interconverted by the gain or loss of
an electron; for example, NADH and NAD+.
Redox Potential - ANSWER-A measure of the tendency of a given redox pair to donate
or accept electrons.
Quinone - ANSWER-Small, lipid-soluble, mobile electron carrier molecules found in the
respiratory and photosynthetic electron-transport chains.
Iron-Sulfur Center - ANSWER-Metal complex found in electron carriers that operate
early in the electron-transport chain; has a relatively weak affinity for electrons.
Cytochrome - ANSWER-Membrane-bound, colored, heme-containing protein that
transfers electrons during cellular respiration and photosynthesis.
, Cytochrome c - ANSWER-A small protein that accepts electrons from the cytochrome c
reductase complex and transfers them to the cytochrome c oxidase complex, has a
redox potential of +230 mV.
Photosynthesis - ANSWER-The process by which plants, algae and some bacteria use
the energy of sunlight to drive the synthesis of organic molecules from carbon dioxide
and water.
Chloroplast - ANSWER-Specialized organelle in algae and plats that contains
chlorophyll and serves as the site in which photosynthesis takes place.
Carbon Fixation - ANSWER-Process by which green plants and other photosynthetic
organisms incorporate carbon atoms from atmospheric carbon dioxide into sugars. The
second stage of photosynthesis.
Stroma - ANSWER-In a chloroplast, the large interior space that contains the enzymes
needed to incorporate CO2 into sugars during the carbon-fixation stage of
photosynthesis; equivalent to the matrix of mitochondria.
Thylakoid - ANSWER-In a chloroplast, the flattened dislike sac whose membranes
contain the proteins and pigments that convert light energy into chemical energy during
photosynthesis. They are arranged in stacks called grana.
Thylakoid Space - ANSWER-The space inside each thylakoid that is connected with
that of other thylakoids.
Light Reactions - ANSWER-In photosynthesis, the set of reactions that converts the
energy of sunlight into chemical energy in the form of ATP and NADPH.
Dark Reactions - ANSWER-In photosynthesis, the set of reactions that produce sugars
from CO2; these reactions, also called carbon fixation, can occur in the absence of
sunlight.
Glyceraldehyde 3-Phosphate - ANSWER-A three carbon sugar that is exported to the
cytosol where it is then used to produce sucrose and a large number of other organic
molecules in the leaves of a plant.
Photosystem - ANSWER-Large multi protein complex containing chlorophyll that
captures light energy and converts it into chemical energy; consists of a set of antenna
complexes and a reaction center.
Antenna Complex - ANSWER-In chloroplasts and photosynthetic bacteria, the part of
the membrane-bound photosystem that captures energy from sunlight; contains an
array of proteins that bind hundreds of chlorophyll molecules and other photosensitive
pigments.
