CHAPTER 8910
In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?
3
Which of the following statements is not true of most cellular redox reactions?
A hydrogen atom is transfered to the atom that loses an electron.
What is the net input involved in glycolysis
ADP, glucose and NAD+
ADP
ATP synthase phosphorylates _____
equation photosynthesis
6 CO2 + 6 H2O → C6H12O6 + 6 O2
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?
6 CO2 molecules are required to produce two G3P molecules, which can be combined to make one glucose molecule.
Which of the following substances is/are involved in oxidative phosphorylation?
ADP, ATP, and oxygen a. ADP b. oxygen c. ATP d. None of the listed responses is correct.
In glycolysis, what starts the process of glucose oxidation?
ATP
Which of the following sequences correctly represents the flow of electrons during photosynthesis?
B) H2O NADPH Calvin cycle A) NADPH O2 CO2 C) NADPH chlorophyll Calvin cycle D) H2O photosystem I photosystem II E) NADPH electron transport chain O2
How would anaerobic conditions (when no O2 is present) affect the rate of electron transport and ATP production during oxidative phosphorylation?
Both electron transport and ATP synthesis would stop.
Which of the following does not occur during the Calvin cycle?
C) release of oxygen A) carbon fixation B) oxidation of NADPH D) regeneration of the CO2acceptor E) consumption of ATP
RuBP
Carbon fixation involves the addition of carbon dioxide to _____. NADPH 3-PGA Rubisco G3P RuBP
The light reactions of photosynthesis supply the Calvin cycle with
D) ATP and NADPH A) light energy. B) CO2and ATP. C) H2O and NADPH E) sugar and O2
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is
D) the H+ concentration gradient across the inner mitochondrial membrane. A) the oxidation of glucose and other organic compounds. B) the flow of electrons down the electron transport chain. C) the affinity of oxygen for electrons. E) the transfer of phosphate to ADP.
An enzyme is ________ when it loses its native conformation and its biological activity.
Denatured
water
Early investigators thought the oxygen produced by photosynthetic plants came from carbon dioxide. In fact, it comes from _____.
_______ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.
Electron transport chain
Which of these is not a product of glycolysis?
FADH2
Which process is not part of the cellular respiration pathway that produces large amounts of ATP in a cell?
Fermentation
ATP, NADPH, O2
From the following choices, identify those that are the outputs of the light reactions. (Recall that inputs to chemical reactions are modified over the course of the reaction as they are converted into products. In other words, if something is required for a reaction to occur, and it does not remain in its original form when the reaction is complete, it is an input.) ATP G3P NADP+ ADP glucose CO2 water O2 light NADPH
In glycolysis, the carbon containing compound that functions as the electron donor is what?
Glucose
Which molecule is metabolized in a cell to produce energy for performing work?
Glucose
Which metabolic pathway is common to both fermentation and cellular respiration of a glucose molecule?
Glycolysis
Which step of the cellular respiration pathway can take place in the absence of oxygen?
Glycolysis
Alcohol Fermentation
Glycolysis followed by the conversion of pyruvate to carbon dioxide and ethyl alcohol
Lactic Acid Fermentation
Glycolysis followed by the conversion of pyruvate to lactate, with no release of carbon dioxide
The immediate energy source that drives ATP synthesis by ATP synthase during oxidative phosphorylation is the
H+ concentration across the membrane holding ATP synthase.
During photosynthesis in chloroplasts, O2 is produced from _____ via a series of reactions associated with _____.
H2O ... photosystem II H20...photosystem I CO2...both photosystem I and the Calvin cycle CO2...photosystem II CO2...the Calvin cycle
6
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose?
3
In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules?
The proximate (immediate) source of energy for oxidative phosphorylation is _____.
Kinetic energy that is realeased as hydrogen ions diffuse down their concentration gradient.
What is the compound that functions as the electron acceptor in glycolysis.
NAD+
The light reactions of photosynthesis generate high-energy electrons, which end up in _____. The light reactions also produce _____ and _____.
NADPH ... ATP ... oxygen water...sugar...oxygen oxygen...sugar...ATP chlorophyll...ATP...NADPH ATP...NADPH...oxygen
The final electron acceptor of cellular respiration is _____.
Oxygen
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is what?
Oxygen
The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why?
The Calvin cycle requires products only produced when the photosystems are illuminated At night, no water is available for the Calvin cycle. Carbon dioxide concentrations decrease at night. It is often too cold at nigh for these reactions to take place. Plants usually open their stomata at night.
Reduction
The addition of electrons to a substance involved in a redox reaction
Most CO2 from catabolism is released during?
The citric acid cycle
d
What is the biological significance of the light-independent reactions of photosynthesis? a. They convert ATP to sugar. b. They generate ATP and NADPH. c. They make oxygen. d. They convert carbon dioxide to sugar.
photosynthesis
Which process produces oxygen?
a
Which set of reactions uses H2O and produces O2? a. The light-dependent reactions b. The light-independent reactions
red, green
_____ has a longer wavelength than _____. Blue ... green Green ... yellow Yellow ... red Violet ... blue Red ... green
Photosystem II
_____ splits water into 1/2 O2, H+, and e- .
Of the metabolic pathways listed below, which is the only pathway found in all organisms?
a. glycolysis b. cellular respiration c. the electron transport chain d. the citric acid cycle e. fermentation
Most of the ATP produced in cellular respiration comes from which of the following processes?
a. oxidative phosphorylation b. substrate-level phosphorylation c. the citric acid cycle d. reduction of NADH e. glycolysis
Starting with one molecule of glucose, the "net" products of glycolysis are a) 2 NAD+, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. b) 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O. c) 6 CO2, 6 H2O, 2 ATP, and 2 pyruvate. d) 6 CO2, 6 H2O, 36 ATP, and 2 citrate. e) 2 FADH2, 2 pyruvate, 4 ATP, and 2 H2O.
b) 2 NADH, 2 H+, 2 pyruvate, 2 ATP, and 2 H2O.
Which of these is NOT a product of glycolysis? a) pyruvate b) FADH2 c) NADH d) ATP
b) FADH2
Carbon fixation involves the addition of carbon dioxide to _____. a) Rubisco b) RuBP c) 3-PGA d) G3P e) NADPH
b) RuBP
Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step _____.
b. enables the cell to recycle the reduced NADH to oxidized NAD+ a. extracts a bit more energy from glucose c. enables the cell to make pyruvate into substances it can use d. prevents pyruvate from accumulating e. removes poisonous oxygen from the environment
In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH2 are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle?
b. two ATP, six NADH, two FADH2 a. about 38 ATP c. four ATP, six NADH, two FADH2 d. one ATP, three NADH, one FADH2 e. three ATP, three NADH, one FADH2
During glycolysis, when glucose is catabolized to pyruvate, most of the energy of glucose is a) transferred directly to ATP. b) used to phosphorylate fructose to form fructose-6-phosphate. c) retained in the pyruvate. d) transferred to ADP, forming ATP. e) stored in the NADH produced.
c) retained in the pyruvate.
In a plant cell, where are the ATP synthase complexes located? a) plasma membrane b) inner mitochondrial membrane c) thylakoid membrane and inner mitochondrial membrane d) thylakoid membrane, plasma membrane and inner mitochondrial membrane e) thylakoid membrane
c) thylakoid membrane and inner mitochondrial membrane
When hydrogen ions are pumped from the mitochondrial matrix across the inner membrane and into the intermembrane space, the result is the a) reduction of NAD+. b) restoration of the Na+/K+ balance across the membrane. c) formation of ATP. d) creation of a proton gradient. e) lowering of pH in the mitochondrial matrix.
d) creation of a proton gradient.
As a result of its involvement in a reaction, an enzyme _____. a) permanently alters its shape. b) loses energy c) is used up d) loses a phosphate group e) is unchanged
e) is unchanged
Muscle tissues make lactate from pyruvate to do which of the following?
e. regenerate NAD+ a. speed up the rate of glycolysis b. utilize the energy in pyruvate c. produce additional CO2 d. get rid of pyruvate produced by glycolysis
Calvin cycle
energy from ATP, electrons from NADPH, and carbon from carbon dioxide are combined to produce sugar molecules.
none
energy input required? water-> P680+
required
energy input required? P700 -> Fd (ferredoxin)
sugar-phosphate backbone
in DNA and RNA, alternating chain of sugar and phosohate
In photosynthesis, what is the fate of the oxygen atoms present in CO2? They end up _____.
in sugar molecules and in water as molecular oxygen as molecular oxygen and in sugar molecules in water in sugar molecules
ferridoxin
iron containing compound that acts as the primary electron acceptor in photosystem; the passes electron off to a series of proteins to the cytochrome complex
RNA polymerase
large molecular complex, links together RNA chain
DNA polymerase
large molecule complex, assembles DNA
Which set of reactions uses H2O and produces O2?
light dependent
The energy used to produce ATP in the light reactions of photosynthesis comes from ___.
movement of H+ through a membrane fluorescence the oxidation of sugar molecules carbon fixation splitting water
Molecular oxygen is produced during _____.
noncyclic electron flow during the light reactions glycolysis cyclic electron flow during the light reactions the Calvin cycle re-energization of electrons by PSI
light dependent reactions
occur in thylakoid membranes that contain an array of proteins and chlorophyl/ other pigments (photosystem) absorbs light and initiates the reactions 1) photosystem 1: excited electrons used to produce nadph 2) photosystem II used to produce ATP oxygen gas released to environment
In mechanism, photophosphorylation is most similar to
oxidative phosphorylation in cellular respiration substrate-level phosphorylation in glycolysis reduction of NADP+ carbon fixation. the Calvin cycle
Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+.
photosytem I
What is the oxidizing agent in the following reaction?
pyruvate oxygen NAD+ NADH lactate
Most of the electrons removed from glucose by cellular respiration are used for which of the following processes?
reducing NAD+ to NADH in glycolysis and the citric acid cycle and producing a proton gradient for ATP synthesis in the mitochondria a. reducing NAD+ to NADH in glycolysis and the citric acid cycle b. producing a proton gradient for ATP synthesis in the mitochondria c. driving substrate-level phosphorylation in glycolysis producing a proton gradient for ATP synthesis in the mitochondria ad driving substrate-level phosphorylation in glycolysis
Which process is most directly by light energy?
removal of electrons from chlorophyll molecules. carbon fixation in the stroma. ATP synthesis. reduction of NADP+ molecules. creation of a pH gradient by pumping protons across the thylakoid membrane.
RNA splicing
removal of introns; joining exons together
genetic code
set of rules that dictates correspondence of RNA codons and amino acids
triplet code
set of three-nucleotide-long "words"; specify amino acids
terminator
special sequence of DNA, makes end of a gene
The calvin cycle occurs in the
stroma matrix stomata thylakoid lumen thylakoid membrane
molecular biology
study of molecular basis of genes and gene expression
transcription
synthesis of RNA on DNA template
translation
synthesis of a polypeptide
Jaganford and Uribe experiment
test chemiosmotic hypothesis by preparing chloroplast memb vesicles 1) grounding up leaves in small fragments 2) from these fragments extract membrane material that formed many tiny spherical vesicles Many of the vesicles were composed of peices of chloroplast membranes. Although not know at the time these vesicles contained the protein ATP synthase found in chloroplasts. 3) scientists prepared a solution of hydrogen ions adjusted ph 4 and the vesicles were placed in it 4) protons slowly crossed the membrane until the solution inside the vesicles was also pH 4 5) the solution outside because pH 8 by reducing proton concentration 6) ADP and inorg phosphate were also introduced and atp produced
If a compound that allows protons to freely diffuse across membranes is added to cells that are actively metabolizing glucose via cellular respiration, which of the following processes would stop?
the chemiosmotic synthesis of ATP a. ATP synthesis b. electron transport c. glycolysis d. All of the listed responses are correct.
Rubisco is ___?
the enzyme in plants that first captures CO2 to begin the Calvin cycle the enzyme responsible for splitting H2O to produce O2 in photosynthesis the first stable intermediate in C4 photosynthesis the enzyme that forms a 4-carbon compound in CAM photosynthesis
What structure is formed by the reaction center, light-harvesting complexes, and primary electron acceptors that cluster, and is located in the thylakoid membrane?
the photosystem the electron transport chain NADP+ reductase ATP synthase the fluorescence center
visible light
the wavelengths that our eyes see as different colors--is only a small fraction of the spectrum.
When chloroplast pigments absorb light ___.
their electrons become excited their photons become excited the Calvin cycle is triggered they become reduced they lose potential energy
codons
three nucleotide sequence in mRNA
start codon
three-nucleotide sequence where tRNA binds
semi conservative model
type of DNA replication, one old strand and one new strand are usesd
tRNA
type of RNA that functions as an interpreter
ribosomal RNA
type of RNA that makes up ribosomes
light independent reaction
use ATP and NADPH to reduce CO2 from the atmosphere to sugar through set of reactions called Calvin cycle
bacteriophage (phage)
virus that infects bacteria
A _______, such as a vitamin, binds to an enzyme and plays a role in catalysis.
Cofactor
H2O, O2
In the light reactions, light energy is used to oxidize _____ to ______
input/ output of calvin cycle
Input: ATP, NADPH, CO2 Output: ADP, G3P, NADP+ Neither input nor output: Light, glucose, O2
input/ output of light reactions
Input: Water, NADP+, ADP, light Output: O2, NADPH, ATP Neither: Glucose, CO2, G3P
What is the role of NADP+ in photosynthesis?
It is reduced and then carries electrons to the Calvin cycle. As a component of photosystem II, it catalyzes the hydrolysis of water. It acts as the primary electron acceptor for the photosystems. As part of the electron transport chain, it manufactures ATP. It assists chlorophyll in capturing light.
In muscle cells, fermentation produces what?
Lactate and NAD+
Which of the following statements is true of the bonds in a water molecule?
Oxygen holds electrons more tightly than hydrogen does, and the net charge is zero.
Where do the reactions of the citric acid cycle occur in eukaryotic cells?
c. the matrix of the mitochondrion a. across the inner membrane of the mitochondrion b. the intermembrane space of the mitochondrion d. the cytosol e. the cristae of the mitochondrion
exons
coding regions
In the Calvin cycle, how many ATP molecules are required to regenerate RuBP from five G3P molecules? a) 1 b) 2 c) 4 d) 5 e) 3
e) 3
Energized electrons from ____ enter an electron transport chain and are then used to reduce NADP+.
Photosystem I
_____ splits water into 1/2 O2, H+, and e- .
Photosystem II
Chlorophyll can be found in _____.
Photosystems I and II
What is the oxidizing agent in the following reaction? Pyruvate + NADH + H+ S Lactate + NAD+
Pyruvate
In fermentation ______ is reduced and ______ is oxidized .
Pyruvate and NADH
Among the products of glycolysis, which compounds contain energy that can be used by other biological reactions?
Pyruvate, ATP and NADH
What is the net input involved in the formation of acetyl CoA?
Pyruvate, NAD+ and coenzyme A
compare red and green wavelength
Red has a longer wavelength than green.
When a compound accepts (gains) electrons, that compound becomes ______. Such a compound is often referred to as an electron acceptor.
Reduced
Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose?
Regneration of RuBP
In a catalyzed reaction a reactant is often called a _______.
Substrate
Oxidation
The loss of electrons from a substance involved in a redox reaction
Where does the formation of acetyl CoA take place?
The mitochondrial matrix
Proton-Motive Force
The potential energy stored in the form of an electrochemical gradient, generated by the pumping of hydrogen ions across a biological membrane during chemiosmosis
Oxidative Phosphorylation
The production of ATP using energy derived from the redox reactions of an electron transport chain; the third major stage of Cellular Respiration
In mitochondrial electron transport, what is the direct role of O2?
To function as the final electron acceptor in the electron transport chain.
For each glucose that enters glycolysis, _____ acetyl CoA enter the citric acid cycle.
Two
In the Calvin cycle, CO2 is combined with ___
a 5-carbon compound to form an unstable 6-carbon compound, which decomposes into two-3-carbon compounds a 7-carbon compound to form two 4-carbon compounds a 5-carbon compound to form a stable 6-carbon that can be converted directly to glucose. two 2-carbon compounds to form a 5-carbon compound. a 2-carbon compound to form a 3-carbon compound.
In glycolysis there is a net gain of _____ ATP. a) 2 b) 3 c) 5 d) 1 e) 4
a) 2
Which of the following are products of the light reactions of photosynthesis that are utilized in the Calvin cycle? a) ATP and NADPH b) electrons and H+ c) ADP, Pi, and NADP+ d) H2O and O2 e) CO2 and glucose
a) ATP and NADPH
In the absence of oxygen, yeast cells can obtain energy by fermentation, resulting in the production of a) ATP, CO2, and ethanol (ethyl alcohol). b) ATP, pyruvate, and acetyl CoA. c) ATP, pyruvate, and oxygen. d) ATP, CO2, and lactate. e) ATP, NADH, and pyruvate.
a) ATP, CO2, and ethanol (ethyl alcohol).
Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2?
b. the combination of the citric acid cycle and electron transport a. the electron transport chain c. the combination of glycolysis and the citric acid cycle d. glycolysis e. the citric acid cycle
Where do the enzymatic reactions of the Calvin cycle take place? a) thylakoid membranes b) outer membrane of the chloroplast c) electron transport chain d) thylakoid space e) stroma of the chloroplast
e) stroma of the chloroplast
Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis?
he light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions.
introns
non-coding regions, intervening
_____ splits water into 1/2 O2, H+, and e- .
photosystem II
In a rosebush, chlorophyll is located in _____.
thylakoids, which are in chloroplasts in the mesophyll cells of a leaf chloroplast, which are in mesophyll cells in the thylakoids of a leaf. mesophyll cells, found within the thylakoids of a leaf's chloroplasts. chlorolasts, which are in thylakoids in the mesophyll cells of a leaf. thylakoids, which are in mesophyll cells in the chloroplast of a leaf
mRNA
type of RNA that encodes DNA to ribosomes
requires input of energy? 1) Water to P680+ 2) P680 to Pq (plastoquinone) 3) Pq to P700+ 4) P700 to Fd (ferredoxin) 5) Fd to NADP+
1) no 2) yes 3) no 4) yes 5) no
Fermentation
A catabolic process that makes a limited amount of ATP from glucose without an electron transport chain and that produces a characteristic end product, such as ethyl alcohol or lactic acid
Citric Acid Cycle
A chemical cycle involving eight steps that completes the metabolic breakdown of glucose molecules begun in glycolysis by oxidizing pyruvate to carbon dioxide; occurs within the mitochondrion in eukaryotic cells and the cytosol of prokaryotes; the second major stage in cellular respiration.
ATP Synthase
A complex of several membrane proteins that provide a port through which protons diffuse. Found in the inner mitochondrial membrane of eukaryotic cells and in the plasma membrane of prokaryotes
Anabolic pathway
A metabolic pathway that consumes energy to synthesize a complex molecule from simpler compounds
Catabolic Pathway
A metabolic pathway that releases energy by breaking down complex molecules to simpler compounds
Beta Oxidation
A metabolic sequence that breaks fatty acids down to two-carbon fragments that enter the citric acid cycle as acetyl CoA
Electron Transport Chain
A sequence of electron carrier molecules that shuttle electrons during the redox reactions that release energy used to make ATP
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
A) The pH of the matrix increases B) ATP synthase pumps protons by active transport. C) The electrons gain free energy. D) The cytochromes phosphorylate ADP to form ATP. E) NAD+is oxidized.
One function of both alcohol fermentation and lactic acid fermentation is to a) oxidize NADH to NAD+. b) reduce FADH2 to FAD+. c) reduce FAD+ to FADH2. d) reduce NAD+ to NADH. e) none of the above
A) oxidize NADH to NAD+
The final electron acceptor of the electron transport chain that functions in aerobic oxidative phosphorylation is
A) oxygen B) water. C) NAD+. D) pyruvate. E) ADP.
Of the following, which occurs during the Calvin cycle?
ATP is hydrolyzed and NADPH is oxidized ATP is reduced and NADPH is oxidized. ATP is oxidized and NADPH is reduced. Noncyclic electron flow produces the materials required for the fixation of carbon from carbon dioxide Light energy is converted to chemical energy
What phosphorylates ADP to make ATP?
ATP synthase
Chloroplast membrane vesicles are equilibrated in a simple solution of pH 5. The solution is then adjusted to pH 8. Which of the following conclusions can be drawn from these experimental conditions?
ATP will not be produced because there is no ADP and inorganic phosphate in the solution.
What is the net output of oxidative phosphorylation?
ATP, NAD+ and Water
What is the net output of glycolysis?
ATP, NADH and pyruvate
What enters the citric acid cycle?
Acetyl CoA
What is not a product of the citric acid cycle?
Acetyl CoA
What is the net input involved in the citric acid cycle?
Acetyl CoA, NAD+ and ADP.
What is the net ouput of the formation of acetyl CoA?
Acetyl CoA, NADH and CO2
A substrate binds to an enzyme at the __________, where the reaction occurs.
Active site
NADPH
After 3-PGA is phosphorylated, it is reduced by _____. NADPH CO2 NADP+ ATP ADP
Glyceraldehyde-3-phosphate (G3P) is produced in the stroma of chloroplast. Which of the following statements is most true about this compound?
All of these are correct For every three molecules of CO2, six molecules of G3P are formed but only one molecule exits the cycle to be used by the plant cell. For every three molecules of CO2, six molecules of G3P are formed but five molecules must be recycled to regenerate three molecules of RuBP. It is a 3-carbon sugar It is produced from glucose during glycolysis.
The use of non-C3 and non-Cam plants as crops may be limited in some regions because on hot, dry days, they close their stomata. What happens as a results of closing their stomata?
All of these are true It prevents carbon dioxide from entering the leaf. it reduces water loss. It builds up oxygen from the light reactions in the leaf. In a process called photorespiration, rubisco binds oxygen instead of carbon dioxide.
Chemiosmosis
An energy-coupling mechanism that uses energy stored in the form of a hydrogen ion gradient across a membrane to drive cellular work, such as the synthesis of ATP.
Cytochrome
An iron-containing protein that is a component of electron transport chains in the mitochondia and chloroplasts of eukaryotic cells and the plasma membrans of prokaryotic cells
Facultative Anaerobe
An organism that makes ATP by aerobic respiration if oxygen is present but switches to anaerobic respiration or fermentation if oxygen is not present.
Obligate Anaerobe
An organism that only carries out fermentation or anaerobic respiration. Such organisms cannot use oxygen.
Which terms describe two atoms when they form a bond in which electrons are completely transferred from one atom to the other?
Anion and Cation
Which of the following statements is a correct distinction between autotrophs and heterotrophs?
Autotrophs, but not heterotrophs, can nourish themselves beginning with CO2 and other nutrients that are inorganic Cellular respiration is unique to heterotrophs Only heterotrophs have mitochondria Only heterotrophs require chemical compounds from the environment Only heterotrophs require oxygen
Of the following, which occurs during the Calvin cycle?
CO2 is reduced ATP and NADPH are synthesized. Light energy is converted to chemical energy. Excited electrons are conveyed from chlorophyll to an electron acceptor. Photons are absorbed.
An enzyme is considered a ________ because it speeds up chemical reactions without being used up.
Catalyst
When properly aligned, the enzyme and substrate form an enzyme-substrate (ES) ______.
Complex
Which metabolic pathway is common to both cellular respiration and fermentation?
D) glycolysis A) the oxidation of pyruvate to acetyl CoA B) the citric acid cycle C) oxidative phosphorylation E) chemiosmosis
pigments in chloroplast
Different pigments absorb light of different wavelengths. One pigment, chlorophyll a, absorbs mainly blue-violet and red light. This molecule participates directly in the light reactions. Another molecule, chlorophyll b, absorbs mainly blue and orange light. We do not see these absorbed colors when we look at a leaf. Instead, we see the green wavelengths that are reflected back from the leaf or transmitted through it.
How is photosynthesis similar in C4 plants and CAM plants?
E. In both cases, rubisco is not used to fix carbon initially. A. In both cases, only photosystem I is used. B. Both types of plants make most of their sugar in the dark. C. Both types of plants make sugar without the Calvin cycle. D. In both cases, thylakoids are not involved in photosynthesis.
Which term describes the degree to which an element attracts electrons?
Electronegativity
electrons
Energized _____ from photosystem I are used to reduce NADP+.
flow of electrons photosynthesis
Energized electrons from photosystem I are passed down an electron transport chain and added to NADP+ to form NADPH. Meanwhile, energized electrons from photosystem II are passed through another electron transport chain. Their energy is used to pump hydrogen ions (H+) from the stroma into the thylakoid compartment, creating a concentration gradient. Electrons leaving this electron transport chain enter photosystem I, replenishing its lost electrons. Photosystem II replenishes its electrons by splitting water. Hydrogen ions and oxygen are released into the thylakoid compartment. This is where the oxygen gas generated by photosynthesis comes from.
Engelmann was able to determine which wavelengths (colors) of light are most effective at driving photosynthesis with aerotactic bateria (O seeking)
First, Engelmann used a prism to disperse white light from the sun into the colors (wavelengths) of the visible spectrum. Then, using a microscope, he illuminated a filament of green algae with the visible spectrum. The photosynthetic pigments in the alga absorbed some of the wavelengths of light, using the absorbed energy to drive the reactions of photosynthesis, including oxygen production. Engelmann used his recently discovered aerotactic bacteria to determine which wavelengths of light caused the alga to photosynthesize most. Because the aerotactic bacteria were attracted to areas of highest oxygen concentration, they congregated around the regions of the alga that photosynthesized the most. He then counted the bacteria associated with each region of the alga illuminated by the various colors of light. Engelmann found that some wavelengths of light attracted more bacteria, suggesting that these wavelengths drive more photosynthesis than others.
What assumptions did Engelmann make in order to conclude that red and violet-blue light were more effective than green light in driving photosynthesis? Select the two that apply.
For Engelmann to be able to draw meaningful conclusions from his experiment, he had to assume that the number of bacteria at any location on the slide was proportional to the amount of oxygen produced by the alga at that location. If this were not the case, the distribution of the bacteria around the alga would be of no use in determining the amount of photosynthesis that occurs at each wavelength. Similarly, it was necessary for Engelmann to assume that the distribution of chloroplasts among the cells in the algal filament was approximately equal. Fewer chloroplasts in one cell compared to another would mean a lower potential for oxygen production at any color.
NADP+, ADP, water, light
From the following choices, identify those that are the inputs of the light reactions. NADP+ ADP water light ATP NADPH O2 glucose CO2 G3P
NADP+, ADP, water, light
From the following choices, identify those that are the inputs of the light reactions. (Recall that inputs to chemical reactions are modified over the course of the reaction as they are converted into products. In other words, if something is required for a reaction to occur, and it does not remain in its original form when the reaction is complete, it is an input.) ATP G3P NADP+ ADP glucose CO2 water O2 light NADPH
ATP, NADPH, O2
From the following choices, identify those that are the outputs of the light reactions. NADP+ ADP water light ATP NADPH O2 glucose CO2 G3P
Which of the following groups of organisms contains only heterotrophs?
Fungi multicellular algae Bacteria unicellular algea Protozoa
Under anaerobic conditions (a lack of oxygen), the conversion of pyruvate to acetyl CoA stops. Why does this occur?
In the absence of oxygen, electron transport stops. NADH is no longer converted to NAD+, which is needed for the first three stages of cellular respiration.
Which red line shows the same action spectrum corrected for the unequal number of photons emitted across the visible spectrum?
Instead, the sun emits the most photons in the yellow part of the spectrum, with relatively fewer photons emitted in the red and violet-blue parts of the spectrum. Thus, the red and violet-blue regions of Engelmann's action spectrum were measured with fewer photons than in the yellow part of the spectrum.
What kind of bond is formed when lithium and fluorine combine to form lithium fluoride?
Ionic
What is the role of NADP+ in photosynthesis?
It forms NADPH to be used in the Calvin cycle. It from part of photosystem II It is the primary electron acceptor. It absorbs light energy. It helps produce ATP from the light reactions
If significant amounts of materials are removed from the citric acid cycle to produce amino acids for protein synthesis, which of the following will result?
Less ATP will be produced by the cell, less CO2 will be produced by the cell, and the four-carbon compound that combines with acetyl CoA will have to be made by some other process. a. Less ATP will be produced by the cell. b. Less CO2 will be produced by the cell. c. The four-carbon compound that combines with acetyl CoA will have to be made by some other process. Less ATP will be produced by the cell and less CO2 will be produced by the cell.
The reduced form of the electron acceptor in glycolysis is what?
NADH
During electron transport, energy from _____ is used to pump hydrogen ions into the _____.
NADH and FADH2 and intermembrane space
Which of the following statements about the electron transport chain is true?
NADH and FADH2 donate their electrons to the chain.
What is the net input in oxidative phosphorylation?
NADH, ADP and O2
What is the net output of the citric acid cycle?
NADH, CO2, ATP and coenzyme A
NAD+ / NADH
Nicotinamde adenine dinucleotide: A coenzyme that can accept an election and acts as an electron carrier in the electron transport chain
In cellular respiration, most ATP molecules are produced by _____.
Oxidative Phosphorylation
When a compound donates (loses) electrons, that compound becomes _______. Such a compound is often referred to as an electron donor.
Oxidized
chemiosmotic hypothesis
Peter Mitchell proposed that ATP synthesis is powered by the potential energy stored in a gradient of protons across a membrane; the flow of electrons through an electron transport chain generates a proton gradient that leads to the synthesis of ATP.
In mitochondria, exergonic redox reactions.
Provide the energy that establishes the proton gradient.
Once the electron donor in glycolysis gives up its electrons, it is oxidized to a compound called what?
Pyruvate
For each glucose that enters glycolysis, _____ NADH + H+ are produced by the citric acid cycle.
Six
An enzyme is considered ________ because of its ability to recognize the shape of a particular molecule.
Specific
In glycolysis, ATP molecules are produced by what?
Substrate level phosphorylation
In the citric acid cycle, ATP molecules are produced by what
Substrate level phosporylation
electromagnetic energy
Sunlight is a type of energy called radiation, or electromagnetic energy. Electromagnetic energy travels through space in a manner similar to the motion of waves in water.
a
Suppose that the concentration of CO2 available for the Calvin cycle decreased by 50% (because the stomata closed to conserve water). Which statement correctly describes how O2 production would be affected? (Assume that the light intensity does not change.) a. The rate of O2 production would decrease because the rate of ADP and NADP+ production by the Calvin cycle would decrease. b. The rate of O2 production would remain the same because the light reactions are independent of the Calvin cycle. c. The rate of O2 production would remain the same because the light intensity did not change. d. The rate of O2 production would decrease because the rate of G3P production by the Calvin cycle would decrease.
Where does the citric acid cycle take place?
The Mitochondrial Matrix
In cellular respiration, a series of molecules forming an electron transport chain alternately accepts and then donates electrons. What is the advantage of such an electron transport chain?
The advantage of an electron transport chain is that a small amount of energy is released with the transfer of an electron between each pair of intermediates.
Cellular Respiration
The catabolic pathways of aerobic and anaerobic respiration, which break down organic molecules for the production of ATP
Where does glycolysis take place?
The cytosol
wave length
The distance between the crests of two adjacent waves
Oxidizing Agent
The electron acceptor in a redox reaction
Reducing Agent
The electron donor in a redox reaction
CO2, G3P
The electrons derived from this oxidation reaction in the Calvin cycle are used to reduce ______ to ________
NADP+, NADPH
The electrons derived from this oxidation reaction in the light reactions are used to reduce ______ to ________
thylakoid
The energy released as electrons are passed along the electron transport chain is used to pump protons into the ______ compartment.
Acetyl CoA
The entry compound for the citric acid cycle in cellular respiration, formed from a fragment of pyruvate attached to a coenzyme
Substrate-Level Phosphorylation
The formation of ATP by an enzyme directly transferring a phosphate group to ADP from and intermediate substrate in catabolism
Which of the following statements accurately describes the function of a metabolic pathway involved in cellular respiration?
The function of glycolysis is to begin catabolism by breaking glucose into two molecules of pyruvate, with a net yield of two ATP.
How will a healthy individual's ATP production change during an eight-hour fast?
The individuals ATP production will no change significantly
Where does oxidative phosphorylation occur?
The inner mitochondrial membrane
e
The light reactions of photosynthesis use _____ and produce _____. a. NADPH ... oxygen b. NADPH ... NADP+ c. carbon dioxide ... oxygen d. carbon dioxide ... sugar e. water ... NADPH
Which of the following statements correctly describes the relationship between the light reactions and the Calvin cycle?
The light reactions produce ATP and NADPH, both of which are used in the Calvin cycle The light reactions produce carbon dioxide and water, all of which are used in the Calvin cycle The light reactions produce ATP and NADPH, both of which are used in the Calvin cycle. The light reactions produce water, ATP, NADPH, all of which are used in the Calvin cycle.
pigments
The molecules that absorb only certain wavelengths of light energy from the Sun in order to begin the photosynthetic reactions are called _____.
Aerobic Respiration
The most efficient catabolic pathway that consumes oxygen and organic molecules, producing ATP. Carried out in most eukaryotic cells and many prokaryotic organisms.
If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result?
The muscle cells will have more trouble making enough ATP to meet their energy requirements, the cells will not be able to carry out oxidative phosphorylation, and the cells will consume glucose at an increased rate. a. The muscle cells will have more trouble making enough ATP to meet their energy requirements. b. The cells will not be able to carry out oxidative phosphorylation. c. The cells will consume glucose at an increased rate.
When electrons flow along the electron transport chains of mitochondria, which of the following changes occurs?
The pH of the matrix increases
true or false? The region of ATP synthase that catalyzes the production of ATP from ADP and inorganic phosphate spans the chloroplast membrane.
The region of ATP synthase that catalyzes ATP production protrudes out of, but does not span, the chloroplast membrane; the region that spans the membrane is an ion channel through which protons can pass.
Glycolysis
The splitting of glucose into pyruvate. Occurs in almost all living cells, serving as the starting point for fermentation or cellular respiration
Anaerobic Respiration
The use of inorganic molecules other than oxygen to accept electrons at the "downhill" end of electron transport chains
CARBONS IN calvin cycle
To produce 1 molecule of G3P (which contains 3 carbons), the Calvin cycle must take up 3 molecules of CO2 (1 carbon atom each). The 3 CO2 molecules are added to 3 RuBP molecules (which contain 15 total carbon atoms), next producing 6 molecules of 3-PGA (18 total carbon atoms). In reducing 3-PGA to G3P (Phase 2), there is no addition or removal of carbon atoms. At the end of Phase 2, 1 of the 6 G3P molecules is output from the cycle, removing 3 of the 18 carbons. The remaining 5 G3P molecules (15 total carbon atoms) enter Phase 3, where they are converted to 3 molecules of R5P. Finally, the R5P is converted to RuBP without the addition or loss of carbon atoms.
True or false? The potential energy in an ATP molecule is derived mainly from its three phosphate groups.
True
True or false? The reactions that generate the largest amounts of ATP during cellular respiration take place in the mitochondria.
True
true
True or false? The light-dependent reactions of photosynthesis use water and produce oxygen
True or false: Cellular respiration and breathing differ in that cellular respiration is at the cellular level, whereas breathing is at the organismal level.
True.
Each Glucose produces how many pyruvates?
Two
How many NADH are produced by glycolysis?
Two
In glycolysis, there is a net gain of ______ ATP.
Two
Why are C4 plants more suited to hot climates than C3 plants?
Unlike C3 plants, they keep fixing carbon dioxide even when the concentration of carbon dioxide in the leaf is low. They do not close their stomata in hot, dry weather. The same cells that bind carbon dioxide perform the Calvin cycle. They evolved in cold weather but migrated to the tropics, where they were more suitable. They suspend photosynthesis in the heat.
oxygen
What important molecule that is needed for cellular respiration is released when water is split in the light reactions of photosynthesis? chlorophyll oxygen rubisco carbon dioxide
b
What is the importance of the light-independent reactions in terms of carbon flow in the biosphere? a. The light-independent reactions turn sugar into ATP for energy. b. The light-independent reactions turn CO2, a gas, into usable carbon in the form of sugars. c. The light-independent reactions use CO2 to make ATP. d. The light-independent reactions turn glucose, a sugar, into CO2 gas.
a
Which of the following molecules is the primary product of photosystem I? a. NADPH b. ATP c. Carbon dioxide d. Oxygen
b
Which of the following reactions ensures that the Calvin cycle can make a continuous supply of glucose? a. Carbon fixation b. Regneration of RuBP c. Production of G3P d. Production of 3-phosphoglycerate
c
Which of the following statements best describes the relationship between the light-dependent and light-independent reactions of photosynthesis? a. The light-independent reactions release energy, and the light-dependent reactions require energy. b. The light-dependent reactions produce carbon dioxide, which is then used by the light-independent reactions. c. The light-dependent reactions produce ATP and NADPH, which are then used by the light-independent reactions. d. The light-dependent reactions pass electrons through an electron transport chain to the light-independent reactions.
c
Which of these equations best summarizes photosynthesis? a. H2O → 2 H+ + 1/2 O2 + 2e- b. 6 CO2 + 6 O2 → C6H12O6 + 6 H2O c. 6 CO2 + 6 H2O → C6H12O6 + 6 O2 d. C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy e. C6H12O6 + 6 O2 → 6 CO2 + 12 H2O
You have a large, healthy philodendron that you carelessly leave in total darkness while you are away on vacation. You are surprised to find that it is still alive when you return. What has the plant been using for an energy source while in the dark?
While it did have access to light before you left, the plant stored energy in the form of sugars or starch, and it was able to derive energy from those during your vacation. None of these. When light energy is not available, plants can derive energy from inorganic molecules. Even though the plant received no visible light, it was able to use the short-wave part of the electromagnetic spectrum (gamma rays and X-rays) to carry out photosynthesis. Even though it can't carry out the light reactions, the plant can still produce sugars because the Calvin cycle doesn't require light.
a
Why is photosynthesis so important to life on Earth? a. Photosynthesis captures light energy from the Sun and stores it in the bonds of glucose, which is then used during cellular respiration to drive the formation of ATP in all plants and animals. b. Photosynthesis breaks down glucose, which provides ATP for all plants and animals. c. Photosynthesis releases carbon dioxide into the air, which is then used during cellular respiration, which in turn drives the release of oxygen, completing the respiration cycle. d. Photosynthesis is used to drive the formation of carbon dioxide, which releases the energy that allows the planet Earth to remain warm.
anticodon
a base triplet of tRNA
Where does the Calvin Cycle occur? a) Stroma b) Chloroplasts c) Thylakoids
a) Stroma
Synthesis of ATP by the chemiosmotic mechanism occurs during a) both photosynthesis and respiration. b) respiration. c) photorespiration. d) photosynthesis. e) neither photosynthesis nor respiration.
a) both photosynthesis and respiration.
Where does glycolysis takes place? a) cytosol b) mitochondrial inner membrane c) mitochondrial matrix d) mitochondrial intermembrane space e) mitochondrial outer membrane
a) cytosol
An enzyme _____. a) is an organic catalyst b) is a source of energy for endergonic reactions c) is a inorganic catalyst d) increases the EA of a reaction e) can bind to nearly any molecule
a) is an organic catalyst
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Produces NADH a) neither the light reactions nor the Calvin cycle b) light reactions alone c) both the light reactions and the Calvin cycle d) occurs in the chloroplast but is not part of photosynthesis e) the Calvin cycle alone
a) neither the light reactions nor the Calvin cycle
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Requires glucose a) neither the light reactions nor the Calvin cycle b) both the light reactions and the Calvin cycle c) the Calvin cycle alone d) occurs in the chloroplast but is not part of photosynthesis e) light reactions alone
a) neither the light reactions nor the Calvin cycle
In glycolysis, ATP molecules are produced by _____. a) substrate-level phosphorylation b) photophosphorylation c) photosynthesis d) cellular respiration e) oxidative phosphorylation
a) substrate-level phosphorylation
In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs?
a. Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH b. Pyruvate is reduced and decarboxylated, and the resulting electrons oxidize an NAD+ to an NADH c. Pyruvate is oxidized and decarboxylated, and the resulting electrons are donated to NADH to produce NAD+. d. Pyruvate is reduced to acetyl-coA, which involves the reduction of pyruvate, the addition of a carbon dioxide from the environment, and its reduction by NADH. e. Pyruvate is ionized directly to acetyl-coA.
Which of the following represents the major (but not the only) energy accomplishment of the citric acid cycle?
a. formation of NADH and FADH2 b. formation of ATP c. formation of CO2 d. completion of substrate-level phosphorylation e. utilization of O2
Sports physiologists at an Olympic training center wanted to monitor athletes to determine at what point their muscles were functioning anaerobically. They could do this by checking for a buildup of which of the following compounds?
a. lactate b. ADP c. oxygen d. carbon dioxide e. ATP
A small amount of ATP is made in glycolysis by which of the following processes?
a. transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation b. attachment of a free inorganic phosphate (Pi) group to ADP to make ATP c. transfer of electrons and hydrogen atoms to NAD+ d. harnessing energy from the sun e. transport of electrons through a series of carriers
photosystem
absorbs protons of light which bump electrons from chlorophyll molecules to electron acceptors. the chlorophyll molecules are oxidized. photosystem 2 transfers the energized electrons to a molecule called plastoquinone via an electron transport chain. the transfer releases enough energy to transport protons across the thylakoid membrane, a proton gradient forms with a higher concentration inside the thylakoid than outside
Based on the work of Engelmann, the wavelengths of light most effective in driving photosynthesis are referred to as _____.
an action spectrum an electromagnetic spectrum an effective spectrum. a visible light spectrum. an absorption spectrum.
The oxygen consumed during cellular respiration is involved directly in which process or event? a) the oxidation of pyruvate to acetyl CoA b) accepting electrons at the end of the electron transport chain c) the citric acid cycle d) the phosphorylation of ADP to form ATP e) glycolysis
b) accepting electrons at the end of the electron transport chain
The primary role of oxygen in cellular respiration is to a) yield energy in the form of ATP as it is passed down the respiratory chain. b) act as an acceptor for electrons and hydrogen, forming water. c) combine with carbon, forming CO2. d) combine with lactate, forming pyruvate. e) catalyze the reactions of glycolysis.
b) act as an acceptor for electrons and hydrogen, forming water.
In chemiosmotic phosphorylation, what is the most direct source of energy that is used to convert ADP + Pi to ATP? a) energy released from substrate-level phosphorylation b) energy released from movement of protons through ATP synthase c) No external source of energy is required because the reaction is exergonic. d) energy released from ATP synthase pumping hydrogen ions from the mitochondrial matrix e) energy released as electrons flow through the electron transport system
b) energy released from movement of protons through ATP synthase
The active site of an enzyme is the region that a) binds the products of the catalytic reaction. b) is involved in the catalytic reaction of the enzyme. c) is inhibited by the presence of a coenzyme or a cofactor. d) binds allosteric regulators of the enzyme.
b) is involved in the catalytic reaction of the enzyme.
Carbon dioxide (CO2) is released during which of the following stages of cellular respiration? a) fermentation and glycolysis b) oxidation of pyruvate to acetyl CoA and the citric acid cycle c) glycolysis and the oxidation of pyruvate to acetyl CoA d) the citric acid cycle and oxidative phosphorylation e) oxidative phosphorylation and fermentation
b) oxidation of pyruvate to acetyl CoA and the citric acid cycle
Which of the following statements is the best explanation of what happens to the temperature and carbon dioxide concentration during a one-hour class period in a classroom of 300 students if the heating and air conditioning is turned off and all doors are kept closed?
b. Temperature and the level of carbon dioxide rise as heat and carbon dioxide are by-products of cellular respiration a. Temperature goes up and the level of carbon dioxide goes down. This is because cellular respiration is an exergonic process that is only about 38% efficient; the remaining energy is lost to the environment as heat. Also, carbon dioxide is being converted to organic molecules such as fats and sugars during cellular respiration. c. Temperature goes down and carbon dioxide levels remain constant. This is because cellular respiration, being an endergonic reaction, requires an input of heat energy from the environment to occur and because carbon dioxide is neither produced nor consumed by cellular respiration. d. Neither temperature nor carbon dioxide levels change because cellular respiration is 100% efficient and because carbon dioxide produced by cellular respiration is just as rapidly consumed by cellular respiration. e. Temperature goes up but carbon dioxide levels remain constant because heat is a by-product of cellular respiration but carbon dioxide is converted to sugar during cellular respiration.
A chemist has discovered a drug that blocks phosphoglucoisomerase, an enzyme that catalyzes the second reaction in glycolysis. He wants to use the drug to kill bacteria in people with infections. However, he cannot do this because _____.
b. human cells must also perform glycolysis; the drug might also poison them a. this step in the pathway of glycolysis can be skipped in bacteria, but not in humans c. bacteria are prokaryotes; they usually don't need to perform glycolysis d. glycolysis produces so little ATP that the drug will have little effect e. glycolysis can occur without the action of enzymes
Which of the following accompanies the conversion of pyruvate to acetyl CoA before the citric acid cycle?
b. release of CO2 and synthesis of NADH a. regeneration of NAD+ c. formation of CO2 and synthesis of ATP d. release of CO2 and release of coenzyme A e. removal of coenzyme A
A photon of which of these colors would carry the most energy?
blue yellow red orange green
What is the range of wavelengths of light that are absorbed by the pigments in the thylakoid membrane?
blue-violet and red-orange green, which is why plants are green the infrared the entire spectrum of white light the range absorbed by carotenoids
nucleotides
building blocks of nucleic acids
How many carbon dioxide molecules must be added to RuBP to make a single molecule of glucose? a) 2 b) 8 c) 6 d) 4 e) 10
c) 6
Which of these equations best summarizes photosynthesis? a) C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + Energy b) H2O → 2 H+ + 1/2 O2 + 2e- c) 6 CO2 + 6 H2O → C6H12O6 + 6 O2 d) C6H12O6 + 6 O2 → 6 CO2 + 12 H2O e) 6 CO2 + 6 O2 → C6H12O6 + 6 H2O
c) 6 CO2 + 6 H2O → C6H12O6 + 6 O2
Which of the following statements best describes the relationship between photosynthesis and respiration? a) ATP molecules are produced in photosynthesis and used up in respiration. b) Respiration is anabolic and photosynthesis is catabolic. c) Photosynthesis stores energy in complex organic molecules, while respiration releases it. d) Photosynthesis occurs only in plants and respiration occurs only in animals. e) Respiration is the reversal of the biochemical pathways of photosynthesis.
c) Photosynthesis stores energy in complex organic molecules, while respiration releases it.
Which metabolic pathway is common to both cellular respiration and fermentation? a) chemiosmosis b) the oxidation of pyruvate to acetyl CoA c) glycolysis d) the citric acid cycle e) oxidative phosphorylation
c) glycolysis
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Produces three-carbon sugars a) neither the light reactions nor the Calvin cycle b) light reactions alone c) the Calvin cycle alone d) both the light reactions and the Calvin cycle e) occurs in the chloroplast but is not part of photosynthesis
c) he Calvin cycle alone
During cellular respiration, acetyl CoA accumulates in which location? a) mitochondrial inner membrane b) mitochondrial outer membrane c) mitochondrial matrix d) cytosol e) mitochondrial intermembrane space
c) mitochondrial matrix
Enzymes work by _____. a) adding energy to a reaction b) decreasing the potential energy difference between reactant and product c) reducing EA d) adding a phosphate group to a reactant e) increasing the potential energy difference between reactant and product
c) reducing EA
Which of the following best describes the electron transport chain?
c. Electrons are passed from one carrier to another, releasing a little energy at each step a. Acetyl CoA is fully oxidized to CO2. b. Glucose is broken down to a three-carbon compound in preparation for the citric acid cycle. d. Electrons are pumped across a membrane by active transport. e. Hydrogen atoms are added to CO2 to make an energy-rich compound
During the reaction C6H12O6 + 6 O2 → 6 CO2 + 6 H2O, which compound is reduced as a result of the reaction?
c. oxygen a. water b. carbon dioxide d. glucose e. both glucose and carbon dioxide
The most important role of pigments in photosynthesis is to
capture light energy screen out harmful ultraviolet rays catalyze the hydrolysis of water store energy catalyze the synthesis of ATP
In photosynthesis, plants use carbon from ___ to make sugar and other organic molecules.
carbon dioxide the sun chlorophyll water soil
ribosomes
cell structure consisting of RNA and proteins
mutation
change in sequence of DNA
In glycolysis, for each molecule of glucose oxidized to pyruvate a) 2 molecules of ATP are used and 2 molecules of ATP are produced. b) 6 molecules of ATP are used and 6 molecules of ATP are produced. c) 4 molecules of ATP are used and 2 molecules of ATP are produced. d) 2 molecules of ATP are used and 4 molecules of ATP are produced. e) 2 molecules of ATP are used and 6 molecules of ATP are produced.
d) 2 molecules of ATP are used and 4 molecules of ATP are produced.
After 3-PGA is phosphorylated, it is reduced by _____. a) CO2 b) ADP c) NADP+ d) NADPH e) ATP
d) NADPH
Which of the following statements best represents the relationships between the light reactions and the Calvin cycle? a) The light reactions provide the Calvin cycle with oxygen for electron flow, and the Calvin cycle provides the light reactions with water to split. b) The light reactions provide ATP and NADPH to the carbon fixation step of the Calvin cycle, and the cycle provides water and electrons to the light reactions. c) There is no relationship between the light reactions and the Calvin cycle. d) The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions. e) The light reactions supply the Calvin cycle with CO2 to produce sugars, and the Calvin cycle supplies the light reactions with sugars to produce ATP.
d) The light reactions provide ATP and NADPH to the Calvin cycle, and the cycle returns ADP, Pi, and NADP+ to the light reactions.
Generation of proton gradients across membranes occurs during a) respiration. b) photorespiration. c) neither photosynthesis nor respiration. d) both photosynthesis and respiration. e) photosynthesis.
d) both photosynthesis and respiration.
Where is ATP synthase located in the mitochondrion? a) electron transport chain b) outer membrane c) cytosol d) inner membrane e) mitochondrial matrix
d) inner membrane
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Produces molecular oxygen (O2) a) both the light reactions and the Calvin cycle b) neither the light reactions nor the Calvin cycle c) the Calvin cycle alone d) light reactions alone e) occurs in the chloroplast but is not part of photosynthesis
d) light reactions alone
Where are the proteins of the electron transport chain located? a) mitochondrial intermembrane space b) mitochondrial matrix c) cytosol d) mitochondrial inner membrane e) mitochondrial outer membrane
d) mitochondrial inner membrane
In general, enzymes are what kinds of molecules? a) carbohydrates b) lipids c) minerals d) proteins e) nucleic acids
d) proteins
Where does the Calvin cycle take place? a) chlorophyll molecule b) outer membrane of the chloroplast c) thylakoid membrane d) stroma of the chloroplast e) cytoplasm surrounding the chloroplast
d) stroma of the chloroplast
What is the primary function of the Calvin cycle? a) use ATP to release carbon dioxide b) split water and release oxygen c) transport RuBP out of the chloroplast d) synthesize simple sugars from carbon dioxide e) use NADPH to release carbon dioxide
d) synthesize simple sugars from carbon dioxide
In mitochondria, chemiosmosis translocates protons from the matrix into the intermembrane space, whereas in chloroplasts, chemiosmosis translocates protons from a) the matrix to the stroma. b) the intermembrane space to the matrix. c) ATP synthase to NADP+ reductase. d) the stroma to the thylakoid space. e) the stroma to the photosystem II.
d) the stroma to the thylakoid space.
When protein molecules are used as fuel for cellular respiration, _____ are produced as waste.
d. amino groups a. fatty acids b. molecules of lactate c. ethanol and CO2 e. sugar molecules
Which of the following is a correct description of the events of cellular respiration and the sequence of events in cellular respiration?
d. oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation a. oxidation of pyruvate; TCA cycle; oxidation of glucose to pyruvate; oxidative phosphorylation b. glycolysis; oxidative phosphorylation; TCA cycle; oxidation of pyruvate. c. oxidation of glucose to pyruvate; reduction of pyruvate; TCA cycle; oxidative phosphorylation e. glycolysis; reduction of pyruvate; TCA cycle; oxidative phosphorylation
The energy given up by electrons as they move through the electron transport chain is used in which of the following processes?
d. pumping H+ across a membrane a. the breakdown of glucose b. the oxidation of water c. the production of CO2 e. the production of NADH and FADH2
Where do the reactions of glycolysis occur in a eukaryotic cell?
d. the cytosol a. the matrix of the mitochondrion b. across the inner membrane of the mitochondrion c. in the intermembrane space of the mitochondrion e. the inner membrane of the mitochondrion
How many NADH are produced by glycolysis? a) 5 b) 4 c) 3 d) 1 e) 2
e) 2
In glycolysis, what starts the process of glucose oxidation? a) NADPH b) hexokinase c) FADH2 d) ADP e) ATP
e) ATP
In the thylakoid membranes, what is the main role of the antenna pigment molecules? a) transfer electrons to ferredoxin and then NADPH b) split water and release oxygen to the reaction-center chlorophyll c) synthesize ATP from ADP and Pi d) concentrate photons within the stroma e) harvest photons and transfer light energy to the reaction-center chlorophyll
e) harvest photons and transfer light energy to the reaction-center chlorophyll
When chemical, transport, or mechanical work is done by an organism, what happens to the heat generated? a) It is used to store energy as more ATP. b) It is used to generate ADP from nucleotide precursors. c) It is transported to specific organs such as the brain. d) It is used to power yet more cellular work. e) It is lost to the environment.
e) it is lost to the environment
Which of the events listed below occur in the light reactions of photosynthesis? a) carbon dioxide is incorporated into PGA. b) NADPH is reduced to NADP+ c) NADP is produced. d) ATP is phosphorylated to yield ADP. e) light is absorbed and funneled to reaction-center chlorophyll a.
e) light is absorbed and funneled to reaction-center chlorophyll a.
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Produces NADPH a) neither the light reactions nor the Calvin cycle b) occurs in the chloroplast but is not part of photosynthesis c) both the light reactions and the Calvin cycle d) the Calvin cycle alone e) light reactions alone
e) light reactions alone
Energy released by the electron transport chain is used to pump H+ ions into which location? a) mitochondrial inner membrane b) mitochondrial outer membrane c) cytosol d) mitochondrial matrix e) mitochondrial intermembrane space
e) mitochondrial intermembrane space
During oxidative phosphorylation, H2O is formed. Where does the oxygen for the synthesis of the water come from? a) lactate (C3H5O3-) b) glucose (C6H12O6) c) pyruvate (C3H3O3-) d) carbon dioxide (CO2) e) molecular oxygen (O2)
e) molecular oxygen (O2)
What name is given to the reactants in an enzymatically catalyzed reaction? a) active sites b) reactors c) EA d) products e) substrate
e) substrate
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Requires ATP a) occurs in the chloroplast but is not part of photosynthesis b) light reactions alone c) neither the light reactions nor the Calvin cycle d) both the light reactions and the Calvin cycle e) the Calvin cycle alone
e) the Calvin cycle alone
For the following question, compare the light reactions with the Calvin cycle of photosynthesis in plants. Requires CO2 a) both the light reactions and the Calvin cycle b) light reactions alone c) neither the light reactions nor the Calvin cycle d) occurs in the chloroplast but is not part of photosynthesis e) the Calvin cycle alone
e) the Calvin cycle alone
The light reactions of photosynthesis use _____ and produce _____. a) carbon dioxide ... oxygen b) carbon dioxide ... sugar c) NADPH ... NADP+ d) NADPH ... oxygen e) water ... NADPH
e) water ... NADPH
Each ATP molecule contains about 1% of the amount of chemical energy available from the complete oxidation of a single glucose molecule. Cellular respiration produces about 32 ATP from one glucose molecule. What happens to the rest of the energy in glucose?
e. It is converted to heat. a. It is released as carbon dioxide and water b. It is converted to starch. c. It is used to make water from hydrogen ions and oxygen. d. It is stored as fat.
When a poison such as cyanide blocks the electron transport chain, glycolysis and the citric acid cycle also eventually stop working. Which of the following is the best explanation for this?
e. NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue a. They run out of ADP. b. Electrons are no longer available from the electron transport chain to power glycolysis and the citric acid cycle. c. A high level of NADH is present in the cell. d. The uptake of oxygen stops because electron transport was inhibited.
In an experiment, mice were fed glucose (C6H12O6) containing a small amount of radioactive oxygen. The mice were closely monitored, and after a few minutes radioactive oxygen atoms showed up in _____.
e. carbon dioxide a. NADH b. oxygen gas c. water d. ATP
Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?
e. the citric acid cycle a. glycolysis b. substrate-level phosphorylation c. oxidative phosphorylation d. anabolic pathways
Oxygen gas (O2) is one of the strongest oxidizing agents known. The explanation for this is that _____.
e. the oxygen atom is very electronegative a. oxygen gas is composed of two atoms of oxygen b. oxygen acts as the final electron acceptor in cellular respiration c. oxygen is so abundant in the atmosphere d. oxygen gas contains a double bond
_____ releases energy that is used to pump hydrogen ions from the stroma into the thylakoid compartment.
electron transport chain
Which of the following is cycled in the cyclic variation of the light reactions?
electrons protons ribulose bisphosphate NADPH ATP
none
energy input required? Pq-> p700+
DNA ligase
enzyme for DNA replication
How many molecules of ATP are gained by substrate-level phosphorylation from the complete breakdown of a single molecule of glucose in the presence of oxygen
four c. about 16 ATP d. three e. about 32 ATP a. two
Which process is the one in which glucose is oxidized to generate two molecules of pyruvate, and in which ATP and NADH are produced?
glycolysis a. chemiosmosis b. fermentation c. the oxidation of pyruvate d. the citric acid cycle
You could distinguish a granum from a crista because the granum, but not the crista, would _____.
have photosynthetic pigments be inside a mitochondrion contain protein but not lipids function in energy transformation all of these are ture
light energy photosynthesis
light energy indirectly fuels ATP by powering transport of electrons (electron transport chain). The energy released during electron transport drives the movement of protons across a membrane (protein gradient) that fuels the production of ATP.
light reactions
light is absorbed by chlorophyll molecules, exciting their electrons. The energy of excited electrons is then used to join ADP and phosphate to form ATP. NADP+ joins with excited electrons to form NADPH, which temporarily stores the energized electrons. In the process, water is split and oxygen is released.
where do photosynthesis, light reactions, and sugar making reactions occur?
photosynthesis occurs in chloroplasts, mainly in leaf cells. The light reactions occur along the thylakoid membranes within the chloroplasts, where pigments capture light energy. The sugar-making reactions of the Calvin cycle occur in the stroma, the fluid between the inner membrane of the chloroplast and the thylakoids.
Chlorophyll can be found in _____.
photosystem I & II
How does carbon dioxide enter the leaf?
through the stomata through the thylakoids through the chloroplasts. through the vascular system. through the roots.
During photosynthesis in a eukaryotic cell, an electrochemical gradient is formed across the___.
thylakoid membrane chloroplast outer membrane stomata chloroplast inner membrane cristae
Chlorophyll molecules are in which part of the chloroplast?
thylakoid membranes stroma thylakoid lumen plasma membrane stomata
During photosynthesis, and electron transport chain is used to
transport electrons from photosystem II to photosystem I transport excited elections from P700 to an electron acceptor. transport excited elections from P680 to an electron acceptor. transport NADPH from the light reactions to the Calvin cycle. transport excited electrons from P700 to an electron acceptor and transport excited electrons from P680 to an electron acceptor.
Both mitochondira and chloroplast ____.
use chemiosmosis to produce ATP reduce NAD+, forming NADP release oxygen as a by-product. are surrounded by a single membrane. obtain electrons from water.
The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from____.
water glucose radioisotopes carbon dioxide light
Where do electrons entering photosystem II come from?
water the electron transport chain ATP chlorophyll molecules in the antenna complex light
The light reactions of photosynthesis use _____ and produce _____.
water/ NaDPH
none
energy input required? Fd -> NADP+
required
energy input required? P680 -> Pq (plastoquinone)
Into which molecule are all the carbon atoms in glucose ultimately incorporated during cellular respiration?
Carbon Dioxide
Which stage of glucose metabolism produces the most ATP?
Electron transport and Chemiosmosis
NADPH, NADP+
The Calvin cycle oxidizes the light-reactions product _____ to _______.
double helix
the form of DNA, spiral ladder shape