Bio 3 Exam 2
The citric acid cycle consists of the oxidation of _______ to produce _______.
acetyl CoA; CO 2, NADH, and FADH 2
Organisms that can survive on carbon dioxide as their principal carbon source are called ______.
autotrophs
Enzymes affect the transition state of a chemical reaction by
binding to substrates providing a surface on which reactions converting substrate to product can occur more rapidly altering the conformation of substrate to approach that of the transition state
Each photocenter in a chloroplast consists of hundreds of antenna pigment molecules that absorb light and transfer energy to a reaction center
chlorophyll.
enzymes act by
decreasing activation energy
the hydrolysis of ATP to ADP and phosphate allows glucose 6 phosphate to be synthesized from glucose and phosphate because the
enzymatic coupling of these two reactions allows energy of ATP hydrolysis to drive the syntehsis of glucose-6-phosphate
Under anaerobic conditions, NADH produced by glycolysis is recycled by a reaction that produces NAD + and
ethanol or lactate
In chloroplasts, a proton gradient is established with a higher concentration of protons found in the ______ and a lower concentration in the ______.
thylakoid lumen, stroma
Light-dependent generation of ATP in photosynthesis occurs in the
thylakoid membrane.
The chloroplast internal membrane is organized into flattened membranous sacs called _________; they, in turn, are arranged in orderly stacks called _______ that contain energy-transducing machinery.
thylakoids, grana
The role of cytochrome c in the electron transport chain is to
transfer electrons from complex III to complex IV.
Fatty acids are broken down in a stepwise process, _______ carbon(s) at a time.
two
Light is captured by _______ different photosystems associated with the thylakoid membranes of chloroplasts.
two
What substance is presently used as the source of electrons for photosynthesis in green plants and cyanobacteria?
water
Coenzyme Q carries electrons from complex _______ to complex _______.
I; III
How many carbons from 13 original glucose molecules enter the Krebs cycle in the absence of oxygen?
0
Glycolysis yields a net gain of _______ ATP molecules per molecule of glucose
2
When electrons from the cofactors reduced by breakdown of one glucose are transferred to oxygen in mitochondria, the process is coupled to the formation of _______ molecules of ATP.
32-34
The light-dependent reactions of photosynthesis provide the light-independent reactions with ______.
ATP and NADPH.
Which of the following is a product of glycolysis that is transported into the mitochondria?
Pyruvate
Photosynthesis uses light energy to chemically convert
CO 2 and H 2O into C 6H 12O 6 and O 2.
Which is the role of the enzyme Rubisco?
Condensation of ribulose 1,5 bisphosphate with carbon dioxide and splitting of a six-carbon product during the Calvin cycle.
Most of the ATP derived from the breakdown of glucose in aerobic cells is derived from glycolysis.
False
What is produced when the electrons leave the electron transport chain of mitochondria and bind to the final electron acceptor for that chain?
H2O
ATP is synthesized in photosynthesis by which of the following means?
Light energy absorbed by photosystems I and II generate energetic electrons that cause the cytochrome bf complex to pump protons across the thylakoid membrane; these protons drive ATP synthase to synthesize ATP.
Together, glycolysis and the citric acid cycle (also known as the Krebs cycle) directly generate two molecules of ATP and two molecules of GTP. Most of the energy derived from the oxidation of glucose comes from the oxidation of the _______ generated from _______.
NADH; the citric acid cycle
What is the plant cell's primary source of reducing power?
NADPH
What is the driving force for photolysis?
NADPH ?
What happens to the carbons of pyruvate that do NOT enter the Krebs cycle?
They are converted to CO2.
Most of the ATP derived from the breakdown of glucose in anaerobic cells is derived from glycolysis
True
The Calvin cycle is involved in the synthesis of _______ from _______.
glucose; carbon dioxide
A stronger oxidizing agent exhibits ___________.
greater electron affinity
What color does chlorophyll reflect?
green
like other catalysts, enzymes
increase rate of reactions without being consumed in reactions do not alter the chemical equilibrium between reactants and products
the free energy change of a reaction is determined by the
intrinsic properties of reactants and products concentrations of reactants and products temperature of reactants and products
NADH produced in glycolysis yields fewer ATP molecules than that produced in the citric acid cycle because
its electrons are shuttled across the mitochondrial inner membrane to complex II.
Which three organelles in a leaf are found closely associated with each other and cooperate with each other in such a way that products of one organelle serve as substrates in another?
mitochondria, chloroplasts, peroxisomes
The ATP synthases of mitochondria and chloroplasts are examples of _______ proteins in which polypeptide rotation provides a mechanical coupling to ATP synthesis.
motor
In photosynthesis, all of the following reactions are directly dependent on light except
nitrogen fixation.
What waste product of photolysis is released to the environment?
oxygen
The electron carrier that transports electrons from cytochrome bf to photosystem I where NADP + is reduced to NADPH is
plastocyanin
Under aerobic conditions, the NADH formed during glycolysis
provides additional energy by donating its electrons to the electron transport chain
Under aerobic conditions, the end product of glycolysis is
pyruvate.
coenzymes are
small molecules that work with an enzyme to enhance reaction rate
The dark reactions occur in the
stroma.
The direct formation of ATP by the transfer of a phosphate group from a donor molecule to ADP is called ________.
substrate-level phosphorylation
The inner mitochondrial membrane contains proteins that
synthesize ATP. B. pump protons. C. transport pyruvate and fatty acids. D. All of the above
Protons are freely permeable across
the outer, but not the inner, mitochondrial membrane
