BIOL 1107: Test 2
183 Cards in this Set
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ch 6
which structure is not part of the endomembrane system?
a. nuclear envelope
b. chloroplast
c. golgi apparatus
d. plasma membrane
e. ER
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b. chloroplast
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ch 6
what structure is common to both plant and animal cells?
a. chloroplast
b. wall made of cellulose
c. central vacuole
d. mitochondrian
e. centriole
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d. mitochondrion
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ch 6
Present in Both Eukaryotic and Prokaryotic
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1. phospholipids bilayer + Protein, selectively permeable barrier, unique environment internally
2. DNA: deoxynucleic acid
-Genes: DNA to RNA to Protein
3. Ribosomes: synthesize proteins
everything inside prokaryotic cell is the cytoplasma, liquid inside is cytosol
in eukaryotic cell…
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ch 6
which of the following is present in a prokaryotic cell?
a. mitochondrion
b. ribosome
c. nuclear envelope
d. chloroplast
e. ER
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b. ribosome
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ch 6
Which structure-function pair is mismatched?
a. Nucleolus: protection of ribosomal subunits?
b. Lysosome: intra cellular digestion?
c. Microtubule: muscle contraction?
d. Golgi: protein trafficking?
e. Ribosome: protein synthesis?
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c. Microtubule: muscle contraction
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ch 6
Cyanide binds to at least one molecule involved in producing ATP. If a cell is exposed to cyanide, most of the cyanide will be found within the
a. ribosomes.
b.peroxisomes.
c.lysosomes.
d.endoplasmic reticulum.
e.mitochondria.
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e.mitochondria
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ch 6
what is the most likely pathway taken by a newly synthesized protein that will be secreted by a cell?
a. ER-->Golgi-->nucleus
b. Golgi--> ER-->lysosomes
c. nucleus-->ER-->golgi
d. ER-->golgi-->vesicles that fuse with plasma membrane
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d. ER--> golgi--> vesicles that fuse with plasma membrane
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ch 6
Which cell would be best for studying lysosomes?
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C) phagocytic white blood cell
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In terms of cellular function, what is the most importantdifference between prokaryotic and eukaryotic cells?
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Eukaryotic cells are compartmentalized, which allows for specialization.
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Bacterial cells are prokaryotic. Unlike a typical eukaryotic cell they _____.
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have no membrane-bounded organelles in their cytoplasm
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Which of the following features do prokaryotes and eukaryotes have in common?
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Ribosomes, plasma membrane, cytoplasm.
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In addition to the fundamental structures required to be defined as a cell, a particular cell also has a nucleus and chloroplasts. Based on this information, this cell could be _____
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a protistal cell and a plant cell
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Connection between nucleolus, nuclear pores, and nuclear membrane?
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Subunits of ribosomes are assembled in the nucleolus and pass through the nuclear membrane via the nuclear pores
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Which of the following isfalse in respect to cells' chromosomes?
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Chromosomes only appear as a cell is about to divide.
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what groups are primarily involved in synthesizing molecules needed by the cell?
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ribosomes
rough er
smooth er
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Which of the following organelles is UNLIKELY to show enhanced abundance in pancreatic cells that secrete large amounts of digestive enzymes?
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free cytoplasmic ribosomes
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A dish of animal cells was grown in the presence of radioactive phosphorous. The phosphorous largely ended up in nucleotides inside the actively growing animal cells. In which cellular structure(s) would you predict the majority of the radioactive phosphorous to accumulate?
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the nucleus
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Which of the following categories best describes the function of the rough endoplasmic reticulum?
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manufacturing
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you would expect a cell with an extensive golgi apparatus to ____
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secrete a lot of protein- the golgi modifies and sorts the lipids and proteins prdouced in the ER. cells that secrete alot of material require an extensive golgi apparatus
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A researcher made an interesting observation about a protein made by the rough endoplasmic reticulum and eventually found in a cell's plasma membrane. The protein in the plasma membrane was actually slightly different from the protein made in the ER. The protein was probably altered in th…
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Golgi apparatus
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Consider a protein that is made in the rough endoplasmic reticulum. You observe that when the synthesis of the protein is completed, the protein is located in the ER membrane. Where else in the cell might this protein be found?
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Embedded in the plasma membrane functioning in the transport of molecules into the cell
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Which of the following sequences represents the order in which a protein made in the rough endoplasmic reticulum might move through the endomembrane system?
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Golgi apparatus → lysosome
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Which of the following is/are most likely to be involved in the process of producing proteins for a chloroplast or mitochondrion?
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free cytoplasmic ribosomes
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a protein that ultimately functions in the plasma membrane of a cell is most likely to have been synthesized _______
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in the rough ER
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Which of the following five membranes is most likely to have a lipid composition that is distinct from those of the other four?
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mitochondrial outer membrane
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Chloroplasts and mitochondria are thought to be of prokaryotic origin. One piece of evidence that supports this hypothesis is that these organelles contain prokaryotic-like ribosomes. These ribosomes are probably most similar to ribosomes found _____.
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in bacterial cells
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Which of the following statements about chloroplasts and mitochondria is true?
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None of these organelles are part of the endomembrane system.
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Reason for grouping peroxisomes with chloroplasts and mitochondria?
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all of these organelles appear to incease in number by dividing
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Which type of cell is most likely to have the most mitochondria?
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muscle cells in the legs of a marathon runner
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Which of the following isfalse?
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mitochondria contain ribosomes in the intermembrane space.
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chloroplasts and mitochondria each contain their own DNA and synthesize some of the proteins that function in these organelles suggests that they
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must divide each time the cell containing them divides
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Which of the following is/are possible site(s) of protein synthesis in a typical eukaryotic cell?
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the cytoplasm
the rough endoplasmic reticulum
in mitochondria
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Which of the following organelles might be found inside other organelles?
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ribosomes
Ribosomes are nonmembranous organelles that are found in the cytoplasm but also in mitochondria and chloroplasts.
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Which of the following lack membranes as part of their structure?
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peroxisomes and ribosomes
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Which is the simplest collection of matter that can live?
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Cell
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A researcher wants to film the movement of chromosomes during cell division. Which type of microscope should she choose and why is it the best choice?
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light microscope, because the specimen is alive
Although the resolution of the light microscope is far less than with electron microscopes, light microscopy is the only technique that permits one to observe living cells.
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Cell fractionation _____.
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separates cells into their component parts
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consider two cells with the same volume but with very different surface areas due to differences in their shapes. the cell with the larger surface area is likely to ...
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be involved in the rapid uptake of compounds from the cells enviroment
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Which of the following are likely to limit the maximum size of a cell
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cells surface-to-volume ratio
the amount of time it takes for a substance to move across the cell
(all choices are correct)
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Which of the following structures is found in eukaryotic but not prokaryotic cells?
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Mitochondria.
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A substance moving from outside the cell into the cytoplasm must pass through _____
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the plasma membrane
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In terms of cellular function, what is the most importantdifference between prokaryotic and eukaryotic cells?
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Eukaryotic cells are compartmentalized, which allows for specialization.
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Microtubules and microfilaments commonly work with which of the following to perform many of their functions?
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None of the listed responses is correct.
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Which of the following structures is found in animal cells but not in plant cells?
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Centrioles.
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Which is a correct statement about the cytoskeleton?
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Components of the cytoskeleton often mediate the movement of organelles within the cytoplasm.
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Cilia and flagella move due to the interaction of the cytoskeleton with which of the following?
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motor proteins
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Where would you expect to find proteins involved with movement of structureswithin a cell?
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cytoskeleton
Movement of organelles and vesicles within cells is accomplished by the cytoskeleton
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Basal bodies are most closely associated with which of the following cell components?
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cilia
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Dye injected into a plant cell that might be able to enter an adjacent cell through a
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Plasmodesmata
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Which of the following correctly compares the extracellular matrix (ECM) of animal cells to cell walls of plant cells?
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Both the ECM and the plant cell wall are composed of varying mixtures of proteins and carbohydrates.
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Your intestine is lined with individual cells. No fluids leak between these cells from the gut into your body. Why?
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the intesinal cells are bound together by tight junctions
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Which of the following statements correctly describes a common characteristic of a plant cell wall and an animal cell extracellular matrix?
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The first two answers are correct.
Both are permeable to water and small solutes and both are produced in the ER and Golgi apparatus.
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The walls of plant cells are largely composed of polysaccharides and proteins that are synthesized in the ____ and ____
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rough ER
Golgi apparatus
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correctly states the relationship between anabolic and catabolic pathways?
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Anabolic pathways synthesize more complex organic molecules using the energy derived from catabolic pathways.
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Which of the following situations does not represent an energy transformation?
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the coupling of ATP hydrolysis to the production of a proton gradient across a membrane by a proton pump
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Organisms are described as thermodynamically open systems. Which of the following statements is consistent with this description?
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Organisms acquire energy from, and lose energy to, their surroundings.
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Consider the growth of a farmer's crop over a season. Which of the following correctly states a limitation imposed by the first or second law of thermodynamics?
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To obey the first law, the crops must represent an open system.
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Which of the following states the relevance of the first law of thermodynamics to biology?
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Energy can be freely transformed among different forms as long as the total energy is conserved.
The first law of thermodynamics states that energy can be transformed but can be neither created nor destroyed.
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Which is the most abundant form of energy in a cell?
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Chemical energy
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Example of Second law of thermodynamics as it applies to biological reactions?
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Aerobic respiration of one molecule of glucose produces six molecules each of carbon dioxide and water
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According to the second law of thermodynamics, which of the following is true?
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The decrease in entropy associated with life must be compensated for by increased entropy in the environment in which life exists.
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If the entropy of a living organism is decreasing, which of the following is most likely to be occurring simultaneously?
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Energy input into the organism must be occurring to drive the decrease in entropy.
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What molecule has the most free energy per molecule?
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a starch molecule
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The electronic arrangement in which of the following molecules means that this (these) molecule(s) has/have greater free energy than the others?
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methane
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Which part of the equation ΔG = ΔH - TΔS tells you if a process is spontaneous?
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ΔG
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If, during a process, the system becomes more ordered, then _____.
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ΔS is negative
more ordered=negative value,
less ordered= positive value
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When one molecule is broken down into six component molecules, which one of the following will always be true?
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ΔS is positive.
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From the equation ΔG = ΔH - TΔS it is clear that _____.
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a decrease in the system's total energy will increase the probability of spontaneous change
increasing the entropy of a system will increase the probability of spontaneous change
increasing the temperature of a system will increase the probability of spontaneous change
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An exergonic (spontaneous) reaction is a chemical reaction that _____.
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releases energy when proceeding in the forward direction
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Which of the following reactions would be endergonic?
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glucose + fructose → sucrose
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Molecules A and B contain 110 kcal/mol of free energy and molecules B and C contain 150 kcal/mol of energy. A and B are converted to C and D. What can be concluded?
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The reaction that proceeds to convert A and B to C and D is endergonic; the products are more organized than the reactants.
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Which of the following determines the sign of ΔG for a reaction?
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the free energy of the reactants and the free energy of the products
By subtracting the free energy of the reactants from the free energy of the products, the ΔG can be calculated and the difference in these values determines the sign of the difference.
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Metabolic pathways are typically far from equilibrium. What processes keep it away?
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-the continuous removal of the products of a pathway to be used in other reactions.
-an input of free energy from outside the pathway
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Which of the following is an example of the cellular work accomplished with the free energy derived from the hydrolysis of ATP, involved in the production of electrochemical gradients?
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proton movement against a gradient of protons
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In general, the hydrolysis of ATP drives cellular work by _____.
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releasing free energy that can be coupled to other reactions
With the help of specific enzymes, the cell can couple the energy of ATP hydrolysis directly to endergonic processes.
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Which of the following statements correctly describes some aspect of ATP hydrolysis being used to drive the active transport of an ion into the cell against the ion's concentration gradient?
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This is an example of energy coupling.
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Much of the suitability of ATP as an energy intermediary is related to the instability of the bonds between the phosphate groups. These bonds are unstable because _____.
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the negatively charged phosphate groups vigorously repel one another and the terminal phosphate group is more stable in water than it is in ATP
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When 1 mole of ATP is hydrolyzed in a test tube without an enzyme, about twice as much heat is given off as when 1 mole of ATP is hydrolyzed in a cell. Which of the following best explains hess observations?
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In the cell, the hydrolysis of ATP is coupled to other endergonic reactions
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What best characterizes the role of ATP in cellular metabolism?
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The free energy released by ATP hydrolysis may be coupled to an endergonic process via the formation of a phosphorylated intermediate.
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The formation of glucose-6-phosphate from glucose is an endergonic reaction and is coupled to which of the following reactions or pathways?
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hydrolysis of ATP
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A chemical reaction is designated as exergonic rather than endergonic when _____.
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the potential energy of the products is less than the potential energy of the reactants
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which of the following is changed by the presence of an enzyme in a reaction?
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the activation energy
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What do the sign and magnitude of the ΔG of a reaction tell us about the speed of the reaction?
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Neither the sign nor the magnitude of ΔG have anything to do with the speed of a reaction.
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How do enzymes lower activation energy?
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by locally concentrating the reactants
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Which of the following statements about enzymes is true?
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Enzymes speed up the rate of the reaction without changing the DG for the reaction.
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Which of the following statements about enzyme function is correct?
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Enzymes can lower the activation energy of reactions, but they cannot change the equilibrium point because they cannot change the net energy output.
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A plot of reaction rate (velocity) against temperature for an enzyme indicates little activity at 10°C and 45°C, with peak activity at 35°C. The most reasonable explanation for the low velocity at 10°C is that _____.
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there is too little activation energy available
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Which of the following statements about enzymes is incorrect?
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An enzyme is consumed during the reaction it catalyzes.
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Which of the following statements about the active site of an enzyme is correct?
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The active site may resemble a groove or pocket in the surface of a protein into which the substrate fits.
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What is meant by the "induced fit" of an enzyme?
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The enzyme changes its shape slightly as the substrate binds to it.
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Which of the following statements correctly describe(s) the role(s) of heat and temperature in biological reactions?
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-The kinetic energy of the substrates is increased as the amount of heat in the system is increased.
.-Heat from the environment is necessary for substrates to get over the activation energy barrier.
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Above a certain substrate concentration, the rate of an enzyme-catalyzed reaction drops as the enzymes become saturated. Which of the following would lead to a faster conversion of substrate into product under these saturated conditions?
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an increase in concentration of enzyme
increasing the temperature by a few degrees
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Which of the following environments or actions would not affect the rate of an enzyme reaction?
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None of the listed responses is correct.
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Enzyme activity is affected by pH because _____.
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high or low pH may disrupt hydrogen bonding or ionic interactions and thus change the shape of the active site
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Which of these statements about enzyme inhibitors is true?erm
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The action of competitive inhibitors may be reversible or irreversible.
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Succinylcholine is structurally almost identical to acetylcholine. If succinylcholine is added to a mixture that contains acetylcholine and the enzyme that hydrolyzes acetylcholine (but not succinylcholine), the rate of acetylcholine hydrolysis is decreased. Subsequent addition of more ac…
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Succinylcholine must be a competitive inhibitor with acetylcholine.
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The process of stabilizing the structure of an enzyme in its active form by the binding of a molecule is an example of _____.
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allosteric regulation
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Which of the following statements about allosteric proteins is/are true?
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They are acted on by inhibitors.
They are sensitive to environmental conditions.
They exist in active and inactive conformations.
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the binding of an allosteric inhibitor to an enzyme causes the rate of product formation by the enzyme to decrease. Which of the following best explains why this decrease occurs?
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the allosteric inhibitor causes a structural change in the enzyme that prevents the substrate from binding at the active site
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Under most conditions, the supply of energy by catabolic pathways is regulated by the demand for energy by anabolic pathways. Considering the role of ATP formation and hydrolysis in energy coupling of anabolic and catabolic pathways, which of the following statements is most likely to be …
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High levels of ADP act as an allosteric activator of catabolic pathways
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a molecule becomes more oxidized when it: loses or gains an electron?
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loses an electron
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In the overall process of glycolysis and cellular respiration, _________ is oxidized and __________ is reduced.
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glucose,oxygen
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Most of the ATP produced in cellular respiration comes from which of the following processes?
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oxidative phosphorylation
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Which of the following is a correct description of the events of cellular respiration and the sequence of events in cellular respiration?
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oxidation of glucose to pyruvate; oxidation of pyruvate; oxidation of acetyl-coA; oxidative phosphorylation
Correct. This is the correct sequence of events in cellular respiration.
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Oxygen gas (O2) is one of the strongest oxidizing agents known. The explanation for this is that _____.
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oxygen is electronegative
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The function of cellular respiration is to _____.
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extract usable energy from glucose
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During the reaction C6H12O6 + 6 O2 →6 CO2 + 6 H2O, which compound is reduced as a result of the reaction
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oxygen
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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?
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It is converted to heat.
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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?
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Temperature and the level of carbon dioxide rise as heat and carbon dioxide are by-products of cellular respiration.
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A small amount of ATP is made in glycolysis by which of the following processes? ( Concept 9.1)
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Correct Answer:
transfer of a phosphate group from a fragment of glucose to ADP by substrate-level phosphorylation
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Where do the reactions of glycolysis occur in a eukaryotic cell? ( Concept 9.1)
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Correct Answer:
the cytosol
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Which process is the one in which glucose is oxidized to generate two molecules of pyruvate, and in which ATP and NADH are produced? ( Concept 9.1)
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Correct Answer:
None of the listed responses is correct.
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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 _____. ( Concept 9.2)
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human cells must also perform glycolysis; the drug might also poison them
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In glycolysis, there is no production of carbon dioxide as a product of the pathway. Which of the following is the best explanation for this? ( Concept 9.2)
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The products of glycolysis contain the same total number of carbon atoms as in the starting material.
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Of the following molecules in the glycolytic pathway (the process of glycolysis), the one with the most chemical energy is _____. ( Concept 9.2)
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Your Answer:
fructose-1,6-bisphosphate Correct. Fructose-1,6-bisphosphate has received two phosphate groups from ATP, conserving some of the energy derived from the hydrolysis of ATP in the fructose-1,6-bisphosphate molecule.
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Most of the NADH that delivers electrons to the electron transport chain comes from which of the following processes?
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Answer:
the citric acid cycle Correct. Both NADH and FADH2 are produced during the citric acid cycle.
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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 _____. ( Concept 9.3)
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Your Answer:
carbon dioxide Correct. One molecule of CO2is formed when pyruvate is converted to acetyl CoA, and two molecules of CO2 are produced in the citric acid cycle.
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In preparing pyruvate to enter the citric acid cycle, which of the following steps occurs? ( Concept 9.3)
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Pyruvate is oxidized and decarboxylated, and the removed electrons are used to reduce an NAD+ to an NADH.
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Why is the citric acid cycle called a cycle? ( Concept 9.3)
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The four-carbon acid that accepts the acetyl CoA in the first step of the cycle is regenerated by the last step of the cycle.
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In the citric acid cycle, for each pyruvate that enters the cycle, one ATP, three NADH, and one FADH2are produced. For each glucose molecule that enters glycolysis, how many ATP, NADH, and FADH2 are produced in the citric acid cycle? ( Concept 9.3)
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two ATP, six NADH, two FADH2
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Where do the reactions of the citric acid cycle occur in eukaryotic cells? ( Concept 9.3)
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Correct Answer:
the matrix of the mitochondrion
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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? ( Concept 9.3)
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Your Answer:
four
Correct. There is a net gain of two ATP from glycolysis and one per each molecule of acetyl CoA oxidized in the citric acid cycle for a total of four per glucose.
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Which of the following represents the major (but not the only) energy accomplishment of the citric acid cycle? ( Concept 9.3)
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Correct Answer:
formation of NADH and FADH2
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After completion of the citric acid cycle, most of the usable energy from the original glucose molecule is in the form of _____. ( Concept 9.3)
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Correct Answer:
NADH
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Which of the following accompanies the conversion of pyruvate to acetyl CoA before the citric acid cycle? ( Concept 9.3)
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release of CO2 and synthesis of NADH
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The energy given up by electrons as they move through the electron transport chain is used in which of the following processes? ( Concept 9.4)
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Correct Answer:
pumping H+ across a membrane
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The ATP synthase in a human cell obtains energy for synthesizing ATP directly from which of the following processes? ( Concept 9.4)
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Correct Answer:
the flow of H+ across the inner mitochondrial membrane through the ATP synthase enzyme
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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? ( Concept 9.4)
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Correct Answer:
NAD+ and FAD are not available for glycolysis and the citric acid cycle to continue.
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Most of the electrons removed from glucose by cellular respiration are used for which of the following processes?
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The first two choices are correct. Electrons from glucose are used to reduce NAD+
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Which part of the catabolism of glucose by cellular respiration requires molecular oxygen (O2) and produces CO2? ( Concept 9.4)
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the combination of the citric acid cycle and electron transport
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During aerobic respiration, molecular oxygen (O2) is used for which of the following purposes? ( Concept 9.4)
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at the end of the electron transport chain to accept electrons and form H2O
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Which of the following substances is/are involved in oxidative phosphorylation?
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the first three listed responses.
ADP, oxygen, ATP
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Which of the following best describes the electron transport chain? ( Concept 9.4)
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Your Answer:
Electrons are passed from one carrier to another, releasing a little energy at each step. Correct. NADH and FADH2 deliver electrons from the breakdown products of glycolysis and the citric acid cycle to the electron transport chain, which passes these electrons from one mo…
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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? ( Concept 9.4)
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none of the above
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Which of the following is the source of the energy that produces the chemiosmotic gradient in mitochondria? ( Concept 9.4)
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Your Answer:
electrons moving down the electron transport chain Correct. Energy from the flow of electrons along the electron transport chain is used to pump hydrogen ions (protons) across the inner mitochondrial membrane, creating the chemiosmotic gradient.
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During respiration in eukaryotic cells, the electron transport chain is located in or on the _____. ( Concept 9.4)
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inner membrane of the mitochondrion
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The overall efficiency of respiration (the percentage of the energy released that is saved in ATP) is approximately _____. ( Concept 9.4)
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Correct Answer:
35%
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When solid tumors of animals reach a certain size, the center of the tumor begins to die. To prevent this, the tumor can recruit new blood vessels. What purpose does the recruitment of blood vessels to growing tumors serve? ( Concept 9.4)
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Your Answer:
The second and third explanations together represent the best answer. Correct. The new blood vessels provide the fuel for cellular respiration: oxygen and glucose. The new blood vessels also eliminate wastes such as carbon dioxide from the tumor. Some anti-cancer drugs att…
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Fermentation is essentially glycolysis plus an extra step in which pyruvate is reduced to form lactate or alcohol and carbon dioxide. This last step ____
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enables the cell to recycle the reduced NADH to oxidized NAD+ (nothig with pyruvate)
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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? ( Concept 9.5)
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Your Answer:
lactate Correct. In humans, muscle cells switch to lactate fermentation after becoming anaerobic.
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In glycolysis in the absence of oxygen, cells need a way to regenerate which compound? ( Concept 9.5)
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Correct Answer:
NAD+
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Muscle tissues make lactate from pyruvate to do which of the following? ( Concept 9.5)
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Correct Answer:
regenerate NAD+
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In brewing beer, maltose (a disaccharide of glucose) is _____. ( Concept 9.5)
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Correct Answer:
the substrate for alcoholic fermentation
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If muscle cells in the human body consume O2 faster than it can be supplied, which of the following is likely to result?
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ALL 3: 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. The cells will consume glucose at an increased rate.
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Of the metabolic pathways listed below, which is the only pathway found in all organisms? ( Concept 9.5)
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Correct Answer:
glycolysis
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When protein molecules are sued as fuel for cellular respiration, ___ are produced as waste
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amino groups
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A gram of fat oxidized by respiration produces approximately twice as much ATP as a gram of carbohydrate. Which of the following best explains this observation? ( Concept 9.6)
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Fats are better electron donors to oxygen than are sugars.
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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?
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Less ATP will be produced by the cell. Less CO2 will be produced by the cell. The four-carbon compound that combines with acetyl CoA will have to be made by some other process.
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In photosynthesis, plants use carbon from _____ to make sugar and other organic molecules. ( Overview)
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Correct Answer:
carbon dioxide
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Which of the following groups of organisms contains only heterotrophs? ( Overview)
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Your Answer:
Fungi Correct. All fungi obtain carbon in a reduced form from other organisms.
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How does carbon dioxide enter the leaf? ( Concept 10.1)
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Correct Answer:
through the stomata
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In a rosebush, chlorophyll is located in _____. ( Concept 10.1)
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Correct Answer:
thylakoids, which are in chloroplasts in the mesophyll cells of a leaf
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Chlorophyll molecules are in which part of the chloroplast? ( Concept 10.1)
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Correct Answer:
thylakoid membranes
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The source of the oxygen produced by photosynthesis has been identified through experiments using radioactive tracers. The oxygen comes from _____. ( Concept 10.1)
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water
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In photosynthesis, what is the fate of the oxygen atoms present in CO2? They end up _____.
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in sugar and in water
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Molecular oxygen is produced during _____. ( Concept 10.1)
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noncyclic electron flow during the light reactions
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The reactions of the Calvin cycle are not directly dependent on light, but they usually do not occur at night. Why? ( Concept 10.1)
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Your Answer:
The Calvin cycle requires products only produced when the photosystems are illuminated.
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The Calvin cycle occurs in the _____. ( Concept 10.1)
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Your Answer:
stroma
Correct. The thylakoids of the chloroplast are the sites of the light reactions, whereas the Calvin cycle occurs in the stroma.
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A photon of which of these colors would carry the most energy? ( Concept 10.2)
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Your Answer:
blue
Correct. The shorter the wavelength, the greater the energy content.
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The most important role of pigments in photosynthesis is to _____. ( Concept 10.2)
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Correct Answer:
capture light energy
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What is the range of wavelengths of light that are absorbed by the pigments in the thylakoid membranes? ( Concept 10.2)
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blue-violet and red-orange
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Based on the work of Engelmann, the wavelengths of light most effective in driving photosynthesis are referred to as _____. ( Concept 10.2)
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Correct Answer:
an action spectrum
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When chloroplast pigments absorb light, _____. ( Concept 10.2)
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Your Answer:
their electrons become excited
Correct. When a molecule absorbs a photon of light, one of the molecule's electrons is elevated to an orbital where it has more potential energy.
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What structure is formed by the reaction center, light-harvesting complexes, and primary electron acceptors that cluster, and is located in the thylakoid membrane? ( Concept 10.2)
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Correct Answer:
the photosystem
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Where do the electrons entering photosystem II come from? ( Concept 10.2)
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Correct Answer:
water
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During photosynthesis in chloroplasts, O2 is produced from _____ via a series of reactions associated with _____.
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H2O ... photosystem II
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during photosynthesis, an electron transport chain is used to___
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transport electrons from photosystem II (water- splitting) to I (nadph producing)
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Which of the following is cycled in the cyclic variation of the light reactions? (Concept 10.2)
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electrons
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Both mitochondria and chloroplasts _____. ( Concept 10.2)
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use chemiosmosis to produce ATP
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You could distinguish a granum from a crista because the granum would have ____.
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photosynthetic pigaments
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During photosynthesis in a eukaryotic cell, an electrochemical gradient is formed across the ______
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thylakoid membrane
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The light reactions of photosynthesis generate high-energy electrons, which end up in ____. The light reactions also produce ____ and ____.
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NADPH ... ATP ... oxygen
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the energy used to produce ATP in the light reactions of photosynthesis comes from _____
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movement of H+ through a membrane
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what is the role of NADP+ in photosynthesis?
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Reduces and then carries electrons to the Calvin Cycle...
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Which of the following occurs during the Calvin Cycle
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Carbon is reduced and NADPH is oxidized
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Which of the following occurs during the calvin cycle of photosynthesis?
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ATP & NADPH are broken down to release energy
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Rubisco is _____. ( Concept 10.3)
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the enzyme in plants that first captures CO2to begin the Calvin cycle
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In the Calvin cycle, CO2 is combined with _____.
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a 5-carbon compound to form an unstable 6-carbon compound, which decomposes into two 3-carbon compounds
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Glyceraldehyde-3-phosphate (G3P) is produced in the stroma of chloroplasts. Which of the following statements is most true about this compound
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It is produced from glucose during glycolysis.
It is a 3-carbon sugar.
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 molecu…
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Which of the following statements correctly describes the relationship between the light reactions and the Calvin cycle?
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The light reactions produce ATP and NADPH, both of which are used in the Calvin cycle.
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What is the role of NADP+ in photosynthesis? ( Concept 10.3)
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Correct Answer:
It forms NADPH to be used in the Calvin cycle.
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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 result of closing their stomata?
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It reduces water loss.
It prevents carbon dioxide from entering the leaf.
In a process called photorespiration, rubisco binds oxygen instead of carbon dioxide.
It builds up oxygen from the light reactions in the leaf.
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Why are C4plants more suited to hot climates than C3 plants?
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Unlike C3 plants, they keep fixing carbon dioxide even when the concentration of carbon dioxide in the leaf is low.
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…
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BIOL 1107: Test 4