Exam 2 Homework/TICA/IKE
A. Primary structure
1. Linear sequence of amino acids
https://d1py7umku9kunm.cloudfront.net/assets/2925478/Calvin_cycle_640.png How many molecules of NADPH are oxidized to NADP+ for the Calvin-Benson cycle in the chloroplast to fix 6 molecules of CO2 to form a molecule of glucose? Include regeneration of RuBP. 1 3 6 9 12 18
12 The diagram shows 3 RuBP + 3 CO2 generating 6 molecules of 3PG, which then are reduced by 6 NADPH to 6 molecules of GAP (G3P). One of the GAP molecules exits, the other 5 rearrange to regenerate 5 RuBP. Since we need 2 molecules of GAP (G3P) to make a molecule of glucose, we need to double everything; hence 12 NADPH will be oxidized to NADP+. Suggestion: do the same calculation for the number of ATP molecules hydrolyzed to ADP to make a molecule of glucose.
B. Secondary structure
2. Formation of alpha helices and beta sheets
C. Tertiary structure
3. Overall 3-D shape of the folded protein
D. Quarternary structure
4. Assembly of 2 or more polypeptide chains into a complex
How many CO2, ATP and NADPH are required to make 1 molecule of glucose from 2 molecules of G3P produced via the Calvin cycle? Start with 6 molecules of RuBP, and end with 6 molecules of RuBP.
6 CO2 18 ATP 12 NADPH
what molecules directly connect mitochondria and chloroplasts - are produced by one and used by the other, with no intermediate steps (no cytoplasmic pathways)? A. carbon dioxide B.oxygen C. atp D.NAD+/NADH E.glucose
A and B A. carbon dioxide B.oxygen
https://d1py7umku9kunm.cloudfront.net/assets/4531205/Blankenship_green-sulfur.jpg The image shows an energy diagram of electron flow in a bacterium that has only a Type I photosystem. This bacterium will be capable of using light energy to (select all that apply): A.reduce NAD(P)+ to NAD(P)H in the presence of a suitable electron donor B.synthesize ATP via photophosphorylation C. split water molecules and produce oxygen gas
A and B A.reduce NAD(P)+ to NAD(P)H in the presence of a suitable electron donor B.synthesize ATP via photophosphorylation
Which of these processes occur in the nucleus? Select all that apply. A. DNA replication B. Transcription of DNA to RNA C. Translation of messenger RNA (mRNA) to make protein
A and B A. DNA replication B. Transcription of DNA to RNA
what molecules directly connect mitochondria and chloroplasts - are produced by one and used by the other, with no intermediate steps? A. carbon dioxide B. oxygen C. atp D. NAD+/NADH E. glucose
A and B A. carbon dioxide B. oxygen
Symbiodinium are eukaryotes. What other lipids would they have in their membranes? Select all that apply. A. sterols like cholesterol B. phospholipids with ether-linked isoprenoid chains C. sphingolipids D.hopanoids
A and C A. sterols like cholesterol C. sphingolipids B/C Only eukaryotes have sterols and sphingolipids in their cell membranes. Bacteria have hopanoids (hopanols) in their membranes instead of sterols. Archaea have phospholipids with isoprenoid chains ether-linked to glycerol. Archaeal membranes are strong enough to not require sterols or hopanoids.
What does the Calvin cycle need to fix carbon dioxide and regenerate RuBP (ribulose-bisphosphate)? A. ATP B. oxygen C. reduced electron carriers D. light
A and C A. ATP C. reduced electron carriers
The oxygenase activity of Rubisco (choose all that apply, or none) A. Occurs when oxygen levels are high and carbon dioxide levels are low B.Results in increased rate of ATP synthesis C. Increases in hot weather D. None of these
A and C A. Occurs when oxygen levels are high and carbon dioxide levels are low C. Increases in hot weather
In a plant cell, where are the ATP synthase complexes located? A. thylakoid membrane B.plasma membrane C. inner mitochondrial membrane D. plant cells do not have ATP synthase complexes
A and C A. thylakoid membrane C. inner mitochondrial membrane
What cellular macromolecules contain large amounts of phosphorus? a. Membrane lipids b. Polysaccharides c. Nucleic acids d. Proteins
A and C a. Membrane lipids c. Nucleic acids
In the absence of respiration, what reactions can cells operate to make ATP? Select all that apply. A. glycolysis B. pyruvate oxidation C. reduction of pyruvate to lactic acid D. the citric acid cycl
A and C A. glycolysis C. reduction of pyruvate to lactic acid
Which of these reactions occur in the cytoplasm in both prokaryotic and eukaryotic cells? Select all that apply. A. glycolysis B. pyruvate oxidation C. fermentation D. citric acid cycle
A and C glycolysis and fermentation
https://d1py7umku9kunm.cloudfront.net/assets/1839176/atrazine_table1.png Atrazine binds to photosystem II (PSII) and prevents oxidation of PSII when it absorbs light energy. How will this affect the other components of the chloroplast thylakoid membrane? Select all correct statements. A. the proton gradient across the thylakoid membrane will decrease B. oxygen gas production will continue C. photosystem I will function normallly D. NADPH production will decrease
A and D A. the proton gradient across the thylakoid membrane will decrease D. NADPH production will decrease
In cyanobacteria and plant chloroplasts, what does photosystem II do? Select all that apply A. gives electrons to the photosynthetic electron transport chain B. gives electrons to NADP+ by way of ferredoxin C. uses light energy to directly to pump protons across the membrane D. splits water molecules to generate oxygen gas
A and D A. gives electrons to the photosynthetic electron transport chain D. splits water molecules to generate oxygen gas
https://d1py7umku9kunm.cloudfront.net/assets/1715661/amino_acid_structures.png Hemoglobin aggregates in sickle cell disease due to a mutation that changes a specific glutamate (Glu) to a valine (Val), . What would you expect in the case of a Glu to aspartate (Asp) mutation? The structures of these amino acids are shown below: A. A change in primary structure B. Aggregation similar to sickle cell C. Large-scale disruption of tertiary structure D. Large-scale disruption of quaternary structure E. Little or no effect on three-dimensional structure F. None of the above
A and E A. A change in primary structure E. Little or no effect on three-dimensional structure
Which of the following is/are NOT true of dehydration/condensation reactions? A. A dehydration reaction results in formation of a covalent bond B. A dehydration reaction results in formation of a water molecule C. A dehydration reaction results in destruction of a water molecule D. Dehydration reactions are used to construct lipids, proteins, nucleic acids, and glycans
A dehydration reaction results in destruction of a water molecule
Which of the following statements about the light reactions of photosynthesis in chloroplasts is/are true? A. Chlorophyll (and other pigments) absorb light energy, which excites electrons. B. ATP is generated by photophosphorylation. C. The splitting of water molecules provides a source of electrons. D. None of these statements are true.
A, B, and C A. Chlorophyll (and other pigments) absorb light energy, which excites electrons. B. ATP is generated by photophosphorylation. C. The splitting of water molecules provides a source of electrons.
Which of the following statements are true about water molecules? Select all that apply. A. water molecules are dipoles B. water molecules form extensive hydrogen bonds with each other C. water molecules form hydrogen bonds with ions and molecules with polar covalent bonds
A, B, and C A. water molecules are dipoles B. water molecules form extensive hydrogen bonds with each other C. water molecules form hydrogen bonds with ions and molecules with polar covalent bonds
Which pathway(s) produce(s) the reduced electron carrier NADH from NAD+ and H+? A. glycolysis C. pyruvate oxidation D. electron transport chain B. citric acid cycle
A, B, and C glycolysis, citric acid cycle, pyruvate oxidation
A protein synthesized on cytoplasmic ribosomes may function in (select all that apply) A. The cytoplasm B. The mitochondria C. The nucleus D. The plasma membrane E. None of the above
A, B, and C A. The cytoplasm B. The mitochondria C. The nucleus
Which of the following biomolecules is/are primarily linear molecules with polarity (directionality)? A. DNA B. RNA C. lipids D. glycans E. proteins
A, B, and E DNA, RNA, and Proteins
Which of the following are true statements about ATP? Select all that are true. A.ATP is a ribonucleotide that can be used to make RNA B.ATP is a deoxyribonucleotide that can be used to make DNA C.Respiring cells synthesize ATP from ADP and inorganic phosphate (Pi) D.The hydrolysis of ATP is an exergonic reaction that can be coupled to endergonic reactions to make the net deltaG negative
A, C, and D A. ATP is a ribonucleotide that can be used to make RNA C.Respiring cells synthesize ATP from ADP and inorganic phosphate (Pi) D.The hydrolysis of ATP is an exergonic reaction that can be coupled to endergonic reactions to make the net deltaG negative
If a cell is fed radioactive phosphate in the culture medium, what macromolecules will become highly radioactive? Select all that apply. A. membrane lipids B. polysaccharides C. DNA D. proteins E. RNA
A, C, and E A. membrane lipids C. DNA E. RNA
What are the products of the light reactions in oxygenic photosynthesis? A.ATP B. ADP C.Carbon dioxide D. Glucose E.NADPH F.NADP G.Water H.Oxygen
A, E, and H A.ATP E. NADPH H.Oxygen
Which is "better" for the reaction with respect to Km: no PC or 1.5mM PC? A. 0 PC B.1.5mM PC C. what??
A. 0 PC
A molecule that is composed primarily of just carbon and hydrogen is most likely: A. a lipid B. a carbohydrate C. a nucleotide D. an amino acid
A. A lipid
Which of these molecules, if radioactively labeled, will be incorporated into newly made CFTR protein? A. Amino acids B. Monosaccharides C. Nucleotides D. Glycerol and fatty acids E. Isoprene
A. Amino acids
A newly discovered, single-celled organism has a circular chromosome and membrane phospholipids with ether-linked isoprenoid chains. Based on this information, this organism belongs to which domain of life? A. Archaea B. Bacteria C. Eukaryotes D. Prokaryotes E. Either Bacteria or Eukaryotes
A. Archaea
https://d1py7umku9kunm.cloudfront.net/assets/165427/nsaids_tylenol.png Which drug(s) bind to the active site of cycloxygenases? A. Aspirin and ibuprofen B. Aspirin and naproxen C. Aspirin, ibuprofen and naproxen D. Only aspirin
A. Aspirin and ibuprofen
Pyruvate dehydrogenase is encoded by a nuclear gene (on X-chromosome). Where in the cell is this enzyme synthesized? A. By free ribosomes in the cytoplasm B. By ribosomes attached to the rough ER C. By ribosomes attached to the nuclear envelope D. By ribosomes located in the mitochondrial matrix
A. By free ribosomes in the cytoplasm
Which of these chlorophyll molecules will have the greatest potential energy after absorption of light? A. Chlorophyll a from cyanobacteria or green plants: absorption at 680 nm B. Bacteriochlorophyll a in purple bacteria: absorption at 870 nm C. Bacteriochlorophyll c in green bacteria: absorption at 740 nm D. Bacteriochlorophyll g in Heliobacteria: absorption at 790 nm
A. Chlorophyll a from cyanobacteria or green plants: absorption at 680 nm
The large subunit of Rubisco is encoded by the chloroplast genome, but the small subunit is encoded by the host nuclear genome. Where in the host cell is the small subunit made? A. Free cytoplasmic ribosomes B. Ribosomes docked to the ER C. Ribosomes in the chloroplast stroma D. Ribosomes docked to the chloroplast envelope E. Ribosomes docked to the thylakoid membrane
A. Free cytoplasmic ribosomes
During strenuous exercise, your muscle cells operate in oxygen-deficit. What food molecules will your body metabolize under such conditions? Select all that apply. A.Glucose B.Fat C. Proteins D. None of these can be metabolized without oxygen
A. Glucose
https://d1py7umku9kunm.cloudfront.net/assets/1840012/energy_metabolism_pathways.png Petite mutants of yeast have defective mitochondria. Without mitochondria, what food sources can these mutants metabolize for energy to make ATP (select all that apply)?
A. Glucose
Looking at the structure of arachidonic acid, where in the cell would you expect to find this molecule? A. In a membrane B. In the cytosol (cytoplasm) C. Cannot be determined from the information provided
A. In a membrane
In response to heat stress, you might also expect the amount of cholesterol in the algal plasma membranes to: A.Increase B. Decrease C. Remain unchanged D. Cholesterol is not present in algal plasma membranes
A. Increase
https://d1py7umku9kunm.cloudfront.net/assets/1854821/Calvin_TLC5s.png What do you think is the first compound produced by incorporating 14CO2? A. PGA B.Sugar diphosphates C.Malic acid D.Aspartic acid E. Sugar phosphates
A. PGA
Match the bond type with the related macromolecule: A. Peptide bond B. Phosphodiester bond C. Glycosidic bond
A. Protein B. Nucleic Acid C. Polysaccharide
If an organism is treated with a drug that inhibits polysaccharide synthesis, what function(s) would be affected? A. Shape/structural integrity B. Energy storage C. Cell-cell signaling/recognition
A. Shape/structural integrity B. Energy storage C. Cell-cell signaling/recognition
Which is the "better" enzyme? A. The enzyme with the higher Vmax B. The enzyme with the lower Vmax C. Vmax is not an informative measure of enzyme activity
A. The enzyme with the higher Vmax
The oxidation of glucose to CO2 and H2O is highly exergonic; ΔGo = -636 kcal/mole. Why doesn't glucose spontaneously combust? A. The glucose molecules lack the activation energy at room temperature B. The oxidation of glucose is not spontaneous C. CO2 has higher energy than glucose D. The formation of 6 CO2 molecules from one glucose molecule decreases entropy E. The water molecules quench the reaction
A. The glucose molecules lack the activation energy at room temperature
The role of NAD+ is to: A. accept electrons from food and transport them to the ETC B.accept electrons from the ETC and transport them to redox centers C.pump protons across the mitochondrial inner membrane D. accept protons from the ETC E. produce ATP at the mitrochondrial inner matrix
A. accept electrons from food and transport them to the ETC
https://d1py7umku9kunm.cloudfront.net/assets/1752206/300px-Aquaporin-Sideview.png https://d1py7umku9kunm.cloudfront.net/assets/1752207/300px-AQP1.png These two figures show 2 different representations of AQP1, an aquaporin. The first image shows the whole aquaporin complex, a tetramer. The second image shows a schematic of a single AQP1 polypeptide chain, showing 6 transmembrane domains. In the first figure, what do the curled ribbons represent? A. alpha helices B. beta-sheets
A. alpha helices
https://d1py7umku9kunm.cloudfront.net/assets/4531204/192px-Chlorophyll_a.svg.png Which of these organisms use chlorophyll (the molecule shown in the figure) to capture light energy for ATP production? Select all that apply. A. cyanobacteria B.green algae and plants C. phototrophic Archea D.phototrophic bacteria E. photosynthetic bacteria (non-oxygenic)
A. cyanobacteria B.green algae and plants D.phototrophic bacteria E. photosynthetic bacteria (non-oxygenic) A, B, D, and E Bacteria and chloroplasts all use chlorophyll molecules, in variant forms, to harvest light energy. Archaea use a completely different pigment, bacteriorhodopsin, to harvest light energy for chemiosmosis and ATP production.
https://d1py7umku9kunm.cloudfront.net/assets/657864/organic-inorganic.png Which of these molecules is (are) organic? A. formic acid B. carbon dioxide C. methane D. carbonic acid
A. formic acid C. methane c-h or c-c is organic for sure Organic molecules have carbon in a reduced form. A good way to tell if a carbon atom is oxidized or reduced is to look at the elements that bond directly to the carbon atom. If the carbon atom has bonds to other carbon atoms or to hydrogen (elements of similar or lesser electronegativity, or affinity for electrons), then the carbon atom is reduced. If the carbon atom has only bonds to oxygen, which has a much higher electronegativity, then the carbon atom is fully oxidized, as in carbon dioxide or carbonic acid. Fully oxidized carbon is considered inorganic.
Which of these reactions occur in the cytoplasm in both prokaryotic and eukaryotic cells? Select all that apply. A. glycolysis B. pyruvate oxidation C. fermentation D. citric acid cycle
A. glycolysis C. fermentation
Hemoglobin is a water-soluble, globular protein made of 2 alpha-hemoglobin and 2 beta-hemoglobin polypeptide chains. Hemoglobin is present in large amounts in the cytoplasm of red blood cells. Where in the cell are the alpha- and beta-hemoglobin proteins made? A. in the cytoplasm, by free cytoplasmic ribosomes B. by ribosomes docked to the rough ER C. by ribosomes docked to the nuclear envelope D. by ribosomes docked to the plasma membrane E. by ribosomes in the mitochondria
A. in the cytoplasm, by free cytoplasmic ribosomes
UCP1, the uncoupling protein located in the inner mitochondrial membrane, is encoded by a gene in the nucleus of the cell, rather than being encoded in the mitochondrial genome. Indeed, relatively few mitochondrial proteins are produced from mitochondrial DNA, and most mitochondrial proteins are produced from DNA in the nucleus of the cell. Where in the cell will the UCP1 protein be synthesized? A. in the cytoplasm, by free cytoplasmic ribosomes B. by ribosomes in the nucleus of the cell C. by ribosomes docked to the endoplasmic reticulum D. by ribosomes located in the mitochondria
A. in the cytoplasm, by free cytoplasmic ribosomes
The electron transport chain in eukaryotic cells is located A.In their mitochondrial inner membranes B. In their mitochondrial outer membranes C. In their plasma membranes D. In the cytoplasm E. In the mitochondrial matrix
A. in their mitochondrial inner membranes
https://d1py7umku9kunm.cloudfront.net/assets/1798925/enzyme-energy-diagram.png Which letter in this diagram represents the activation energy for the enzyme-catalyzed reverse reaction, C + D → A + B? A. letter a B. letter b C. letter c D. letter d E.letter e F. reactions cannot run in reverse
A. letter a
A major cause of coral bleaching in recent years has been warmer ocean temperatures. The membranes of the photosynthetic algal symbiont appears particularly sensitive to increase in temperature. At higher temperatures, membranes with a given lipid composition will become _____ A. more fluid, and more leaky B. more rigid, and less leaky
A. more fluid, and more leaky
Recall that fatty acids are metabolized by cleaving the fatty acid chains 2 carbon atoms at a time, to produce acetyl-coA. Under what conditions can human cells metabolize fatty acids? A. only when cells are undergoing aerobic respiration B. only when cells are operating lactic acid fermentation C. at all times
A. only when cells are undergoing aerobic respiration
Prokaryotes differ from eukaryotes in which of the following ways? Select all that apply. A. prokaryotic cells are generally smaller than eukaryotic cells B. prokaryotic cells have circular chromosomes C. prokaryotic cells have chromosomal DNA enclosed in the nucleus D. prokaryotic cells lack ribosomes
A. prokaryotic cells are generally smaller than eukaryotic cells B. prokaryotic cells have circular chromosomes
Atrazine binds to photosystem II (PSII) and prevents oxidation of PSII when it absorbs light energy. How will this affect the other components of the chloroplast thylakoid membrane? Select all correct statements. A. the proton gradient across the thylakoid membrane will decrease B. oxygen gas production will continue C. photosystem I will function normallly D. NADPH production will decrease
A. the proton gradient across the thylakoid membrane will decrease
Kneeland et al. (2013) examined changes in lipid composition of Symbiodinium, the usual alga that resides in coral cells and provides the coral with food made from photosynthesis. https://d1py7umku9kunm.cloudfront.net/assets/2836363/Kneeland_etal_Fig1.png Figure 1 shows the % of C-18 fatty acids that are unsaturated (have one or more double bonds between carbons), in lipids extracted from algal cells cultured at different temperatures over 4 weeks. The algal cells grown at higher temperatures decrease their percentage of unsaturated fatty acids over time. How will decreasing the percentage of unsaturated fatty acids change the properties of the algal membranes? A. their membranes will be more rigid and less leaky B. their membranes will be more fluid and less leaky C. their membranes will be more rigid and more leaky D. their membranes will be more fluid and more leaky
A. their membranes will be more rigid and less leaky
If cells had time to adapt to the presence of cyanide, how might they be able to recover high rates of ATP synthesis? A. they could speed up glycolysis and lactic acid fermentation B.they could speed up the citric acid cycle C. they could metabolize fatty acids instead of glucose
A. they could speed up glycolysis and lactic acid fermentation
https://d1py7umku9kunm.cloudfront.net/assets/2883702/Collins_Fig1_edited.png Newborn babies have "brown fat" cells that make a mitochondrial inner membrane protein called UCP1, that acts as a channel for facilitated diffusion of protons. When this channel opens, and ATP synthesis decreases while oxygen consumption increases, what happens to the free energy released by the electron transport chain? A.More of the free energy released by the electron transport chain is converted to heat energy B. Since less ATP is made, less free energy is released by the electron transport chain
A.More of the free energy released by the electron transport chain is converted to heat energy A The oxidation of NADH to NAD+ and H2O will always release the same amount of free energy. If less of that free energy is stored in the form of ATP, then more of that free energy becomes waste heat. Newborn mammals exploit this mechanism to generate body heat.
https://d1py7umku9kunm.cloudfront.net/assets/2883702/Collins_Fig1_edited.png Newborn babies have "brown fat" cells that make a mitochondrial inner membrane protein called UCP1, that acts as a channel for facilitated diffusion of protons. When this channel opens, what will be the effect on the rate of oxygen consumption? Assume there is no limitation on availability of either NADH or oxygen. A.The rate of oxygen consumption will increase B.The rate of oxygen consumption will decrease C.The rate of oxygen consumption will stay the same
A.The rate of oxygen consumption will increase A The rate of oxygen consumption is the rate of respiration, which is the rate of electron flow through the electron transport chain (ETC). If neither NADH (the source of electrons for the ETC) nor oxygen (the sink for electrons from the ETC) are limiting, then the rate of electron flow will be determined by the ease or difficulty (energy-wise) of pumping protons across the membrane. If the membrane is fully charged, with a large proton gradient, then more energy will be required for active transport of protons against gradient, and the rate of electron flow will decline (each complex in the ETC pumps one proton per electron it passes on). If, as a result of UCP1 channels opening, the proton gradient is depleted, then it will take very little energy to transport protons and the rate of electron flow will be high. So the rate of oxygen consumption will increase when UCP1 channels open. However, this oxygen consumption is no longer fully linked to ATP synthesis. Another way to think about this question is to consider the effect of UCP1 on the cell's ability to produce ATP. Because UCP1 causes the mitochondrial inner membrane to become 'leaky' to hydrogen, it means the proton gradient is 'breaking down.' Maintaining the proton gradient requires pumping more protons across the membrane, which means increasing the activity of the ETC, and thus meaning there are more electrons that must be deposited on a terminal electron acceptor (oxygen)
https://d1py7umku9kunm.cloudfront.net/assets/2883699/mudwatt.png The diagram shows a simple microbial fuel cell (Mudwatt by KeegoTech). Soil bacteria in the anoxic zone grow on the surface of the anode, by metabolizing organic molecules in the soil. They carry on anaerobic respiration, and use the anode as the terminal electron acceptor. These electrons are then conducted by a wire to the cathode at the surface of the soil, where the electrons combine with oxygen gas to make water. What is the ultimate source of electrons collected by the anode? A.organic molecules B. water molecules C.oxygen (O2) D.carbon dioxide
A.organic molecules
Oxidative phosphorylation occurs in A. All cells in the presence of oxygen B. Only in mitochondria in the presence of oxygen C. Only in mitochondria, using either oxygen or alternative electron acceptors D. All respiring cells, using either oxygen or alternative electron acceptors E. All respiring cells, except Archaea
All respiring cells, using either oxygen or alternative electron acceptors
Some membrane lipids are characteristic of only one of the 3 domains of cellular life. Match the domain of life with the membrane lipid their cell membranes contain. Archaea - Bacteria - Eukarya -
Archaea - ether-linked isoprenoid chains Bacteria - ester-linked fatty acid chains and hopanoids Eukarya - ester-linked fatty acid chains and sterols
What pathways release the carbon atoms from glucose as CO2? Select all that apply. A. Glycolysis B. Pyruvate oxidation C. Citric acid cycle D. Electron transport chain
B and C Pyruvate oxidation Citric acid cycle
Choose all that apply: if all of a cell's reactions are at chemical equilibrium, A. no reactions occur in the cell B. a cell cannot expend energy to accomplish work C. all of a cell's energy expenditure is given off as waste heat D. the delta G is zero for all of the cell's reactions
B and D B. a cell cannot expend energy to accomplish work D. the delta G is zero for all of the cell's reactions
Aerobic respiration: A. produces oxygen as a result of chemiosmosis B.consumes oxygen and produces water C. does not produces as much ATP as anaerobic respiration D.uses an electron transport chain to produce a proton gradient
B and D B.consumes oxygen and produces water D.uses an electron transport chain to produce a proton gradient
Pyruvate dehydrogenase carries out pyruvate oxidation. What are the products that result from pyruvate dehydrogenase activity? Select all that apply. A.Pyruvate B.Acetyl-CoA C.CO2 D. NADH E. Citric acid
B, C, and D B.Acetyl-CoA C.CO2 D. NADH
Which of the following show(s) saturation kinetics? Select all that apply A.simple diffusion B active transport C. facilitated diffusion D.enzyme-catalyzed reactions E.none of these show saturation kinetics
B, C, and D active transport, facilitated diffusion, enzyme-catalyzed reactions
What isotope could you use to label newly synthesized CFTR protein, but not lipids, carbohydrates or nucleic acids? Select all that apply. A. 32P B. 35S C. 15N D. 14C E. 18O
B. 35S
An organism that gets electrons from H2 and makes its own organic carbon from carbon dioxide is classified as a: A.Chemoheterotroph B. Chemoautotroph C.Photoheterotroph D.Photoautotroph
B. Chemoautotroph
Which of the following is NOT an input to glycolysis? Choose all that apply. A. Glucose B. CoA (co-enzyme A) C. ADP D. NAD+
B. CoA (co-enzyme A)
https://d1py7umku9kunm.cloudfront.net/assets/173977/18O-labeling.png Figure from Purves et al. Life, the Science of Biology, 6th ed. Leaves were exposed to either 18O-labeled CO2 (expt 1) or 18O-labeled water (expt 2). In which experiment will the leaves produce 18O-labeled oxygen gas? Select one, both, or none. A. Experiment 1 B. Experiment 2
B. Experiment 2
The passage of water molecules across cell membranes through aquaporins is an example of: A. Simple diffusion B. Facilitated diffusion C. Active transport D. Endocytosis
B. Facilitated diffusion
https://d1py7umku9kunm.cloudfront.net/assets/803449/ATP_production_pathways.png Which foods can Patrick's cells metabolize to generate ATP without lactate acidosis? Select all that apply. A. Carbohydrates B. Fatty acids C. Proteins
B. Fatty acids Any food that results in production of pyruvate will cause lactate acidosis. Fatty acids are the only molecules that do not generate any pyruvate. Some amino acids are metabolized to form pyruvate, and carbohydrates are broken down to glucose, which generates pyruvate as the end-product of glycolysis.
In what part of a protein would you expect to find a hydrophobic amino acid like tryptophan? A. On the surface of a globular (free-floating) protein B. In the interior of a globular (free-floating) protein C. In the part of a membrane-bound protein that interacts with membrane lipids
B. In the interior of a globular (free-floating) protein C. In the part of a membrane-bound protein that interacts with membrane lipids
Which of the following treatments would be most effective in managing the respiratory symptoms caused by cystic fibrosis? A. Inhalation of distilled water vapor B. Inhalation of aerosolized hypertonic salt solution C. Inhalation of aerosolized isotonic salt solution
B. Inhalation of aerosolized hypertonic salt solution
If oxygen were NOT present at the cathode, what would happen to the electricity output of the MFC? A. It would increase (more electricity) B. It would decrease (less electricity) C.It would not change
B. It would decrease (less electricity)
Oxygenic photosynthesis provides an important advantage over anoxygenic photosynthesis because (select all that apply) A. Only oxygenic photosynthesis can produce both ATP and reduced electron carriers B. The ability to extract electrons from water frees oxygenic photosynthesizers from dependence on reducing compounds like hydrogen sulfide C. Only oxygenic photosynthesizers can reduce carbon dioxide to make organic carbon
B. The ability to extract electrons from water frees oxygenic photosynthesizers from dependence on reducing compounds like hydrogen sulfide
50 g of radish seeds are germinated with water in the light, or with water in the dark, for several days until their first true leaves have appeared. Control seeds have no water and no light. Each batch of seeds is then carefully dried to remove all water, and weighted. Which batch of radish seeds will have the least dry mass? A. The light-germinated seeds B. The dark-germinated seeds C. The controls D.The seeds will all have the same dry mass
B. The dark-germinated seeds
An organism that can use light energy to make ATP via photophosphorylation, but still requires organic carbon as a food source to grow, is best classified as: A. a photoautotroph B. a phototroph C. a heterotroph D. a chemoautotroph
B. a phototroph
The passage of protons through UCP1 is inhibited by ADP. ADP does not bind to the proton channel. Therefore, we could classify ADP as: A. a competitive inhibitor of UCP1 B. an allosteric (non-competitive) inhibitor of UCP1 C.a substrate of UCP1
B. an allosteric (non-competitive) inhibitor of UCP1
https://d1py7umku9kunm.cloudfront.net/assets/4531244/Blankenship_purple.jpg This image shows an energy diagram of electron flow in a bacterium that has only a Type II photosystem. After the photosystem absorbs light energy, it gives electrons to_____ A.ATP synthase B. an electron transport chain in the membrane C. oxygen molecules D.NAD+
B. an electron transport chain in the membrane
Red blood cells are placed in a hypotonic solution (deionized water), and they swell up. How does water get into the cells? A. by simple diffusion through the lipid bilayer membrane B. by facilitated diffusion through aquaporins C. by active transport through aquaporins D. by hitchhiking with phosphate, glucose, and other molecules that are transported into the cell
B. by facilitated diffusion through aquaporins
Cyclooxygenase is located in the lumen of the ER. The enzyme is synthesized A. by free cytoplasmic ribosomes B. by ribosomes docked to the rough ER C. by ribosomes in the nucleus D. by ribosomes docked to the Golgi E. by ribosomes in the mitochondria
B. by ribosomes docked to the rough ER
What are the substrates for Rubisco (ribulose-1,5-bisphosphate carboxylase/oxygenase)? A. carbon dioxide and acetyl-coA B. carbon dioxide and RuBP (ribulose-1,5-bisphosphate) C. RuBP and ATP D. RuBP, CO2 and ATP E. RuBP, CO2, ATP and NADPH
B. carbon dioxide and RuBP (ribulose-1,5-bisphosphate)
Blood glucose levels are typically around 5 mM. Cytosolic glucose concentrations in most cells of the body are lower - 1 mM or less. Therefore, glucose can enter bodily cells from the bloodstream via____ A.simple diffusion B. facilitated diffusion (facilitated transport) C. active transport
B. facilitated diffusion (facilitated transport)
The airway epithelial cells maintain a thin layer of watery liquid containing salt. Their cilia beat in the watery liquid to move mucus and particles out of the airway and into the back of the throat, where it is swallowed into the digestive tract. To maintain salt balance, the CFTR channel opens to allow Cl- ions to diffuse across the cell membrane and into the airway liquid. In the absence of CFTR function, the airway liquid becomes hypotonic. Which way will water molecules flow? A. from the surrounding cells into the airway B. from the airway into the cells that line the airway C. there will be no net movement of water into or out of the airway
B. from the airway into the cells that line the airway
Both alpha- and beta-hemoglobin chains have mostly alpha-helices, and no beta-sheets. What forces or bonds are responsible for formation and stabilization of alpha-helices? A. covalent disulfide bonds B. hydrogen bonds C. ionic bonds D. hydrophobic interactions E. Van der Waals interactions
B. hydrogen bonds
You are now convinced that you know the cause of death for these victims and quickly report it back to the police as this is a very dangerous situation. After realizing that the electron transport chain was no longer functioning, you started to suspect poisoning and ran a blood test for various poisons that you knew affected the electron transport chain. The test of all seven patients came back positive for cyanide. Cyanide irreversibly binds to cytochrome c oxidase (CcOX) of the electron transport chain and prevents the transfer of electrons to oxygen, the final electron acceptor. In the presence of cyanide, what would happen to the flow of electrons down the electron transport chain (ETC)? A. it would increase B. it would decrease C. it would stay the same
B. it would decrease With cytochrome c oxidase unable to transfer electrons to oxygen, the electrons would back up in the ETC, and electron flow will stop.
You are now convinced that you know the cause of death for these victims and quickly report it back to the police as this is a very dangerous situation. After realizing that the electron transport chain was no longer functioning, you started to suspect poisoning and ran a blood test for various poisons that you knew affected the electron transport chain. The test of all seven patients came back positive for cyanide. Cyanide irreversibly binds to cytochrome c oxidase (CcOX) of the electron transport chain and prevents the transfer of electrons to oxygen, the final electron acceptor. In the presence of cyanide, what would happen to the proton gradient across the inner mitochondrial membrane? A. it would increase B. it would decrease C. it would stay the same
B. it would decrease With no electron flow, no protons will be pumped across the inner mitochondrial membrane. The proton gradient that exists will quickly dissipate as protons return through the ATP synthase, until the proton concentrations are nearly the same on both sides of the membrane.
In the presence of cyanide, what would happen to the rate of ATP synthesis in the mitochondria? A. it would increase B. it would decrease C. it would stay the same
B. it would decrease With no electron flow, no protons will be pumped across the inner mitochondrial membrane. The proton gradient that exists will quickly dissipate as protons return through the ATP synthase, until the proton concentrations are nearly the same on both sides of the membrane. ATP synthesis will slow as the proton gradient decreases, and stop completely when the proton gradient is too small.
Cell membranes are lipid bilayers, consisting of an outer leaflet facing the outside of the cell and an inner leaflet interacting with the cytoplasm. Can lipids flip from the outer face to the inner face, and vice versa? A.Yes B. No
B. no The hydrophilic heads (glycerol-phosphate) are too hydrophilic to traverse the hydrophobic inner core of the lipid bilayer. Also, cell membranes have a different composition of lipids in the outer and inner leaflets. Such differences would be impossible to maintain if lipids could flip back and forth
Organic extractions separate molecules according to their polarity. Polar molecules stay in the aqueous phase, whereas non-polar molecules dissolve in the organic solvent phase. When cells are broken (lysed) and extracted with organic solvents, which of these molecules will be dissolved in the aqueous (water) phase? Select all that apply. A. lipids B. nucleic acids C. carbohydrates D.small charged and polar molecules
B. nucleic acids C. carbohydrates D.small charged and polar molecules
What components of biomass contain large amounts of nitrogen? A. carbohydrates and proteins B. nucleic acids and proteins C. proteins and lipids D. lipids and polysaccharides E. proteins, lipids, carbohydrates and nucleic acids
B. nucleic acids and proteins
The facilitated transport of glucose into cells by glucose transporters will show what type of kinetics (plots of rate of transport versus concentration of glucose outside the cell)? A. simple linear kinetics B. saturation kinetics
B. saturation kinetics
https://d1py7umku9kunm.cloudfront.net/assets/4531226/Blankenship_purple.jpg This image shows an energy diagram of electron flow in a bacterium that has only a Type II photosystem. This bacterium would be capable of using light energy to: A. reduce NAD(P)+ to NAD(P)H in the presence of a suitable electron donor B. synthesize ATP C.produce oxygen gas
B. synthesize ATP
If a thylakoid is punctured so that the interior of the thylakoid is no longer separated from the stroma, which of the following processes will be most directly affected? A. the flow of electrons from photosystem II to photosystem I B. the synthesis of ATP C. the reduction of NADP+ D. the splitting of water E. the absorption of light energy by chlorophyll
B. the synthesis of ATP
https://d1py7umku9kunm.cloudfront.net/assets/5303577/atrazine_table1.png From the data in this table, how do these herbicides kill plants? A. they inhibit oxidative phosphorylation B. they inhibit photophosphorylation C.they inhibit cellular respiration D.cannot tell from the data provided
B. they inhibit photophosphorylation
Plant a seedling in a large pot with 100 kgs of soil. Water daily for 5 years. The tree now weighs 50 kgs. The soil is carefully recovered, dried and weighed. How much will the soil weigh? A. About 150 kgs B.About 100 kgs C.About 50 kgs
B.About 100 kgs
Is PC a stimulator or an inhibitor of Cox-1 activity? A. Stimulator B.Inhibitor C. Cannot be determined from the information provided
B.Inhibitor
If oxygen were present at the anode, what would happen to the electricity output of the MFC? A. It would increase (more electricity) B.It would decrease (less electricity) C.It would not change
B.It would decrease (less electricity)
Which reagents added to the mud around the anode would boost electric power output? A.Oxygen B.More organic food molecules C. Better alternative terminal electron acceptors such as Fe3+ or nitrate D. microbicide (antibiotic)
B.More organic food molecules Since the electrons come from organic food molecules, having more food molecules should provide more electrons (and more bacterial growth). Oxygen is the preferred terminal electron acceptor; if oxygen was available near the anode, the bacteria would simply respire using oxygen and will not deposit their electrons to the anode. Similarly, having better terminal electron acceptors will cause bacteria to use them instead of the anode. A microbicide will kill bacteria; without bacteria, no respiration will take place, and no electrons will be transferred from organic food molecules in the soil to the anode.
https://d1py7umku9kunm.cloudfront.net/assets/2883702/Collins_Fig1_edited.png Newborn babies have "brown fat" cells that make a mitochondrial inner membrane protein called UCP1, that acts as a channel for facilitated diffusion of protons. When this channel opens, what will be the effect on the rate of ATP synthesis? A. The rate of ATP synthesis will increase B.The rate of ATP synthesis will decrease C.The rate of ATP synthesis will stay the same
B.The rate of ATP synthesis will decrease The energy to power ATP synthesis comes from the proton gradient that drives protons through ATP synthase. UCP1 channels create holes in the membrane that will allow protons to leak across, through the UCP channels instead of ATP synthase, and thus decrease ATP production.
When in the open configuration, UCP1 allows the passage of protons across the membrane from the side with higher proton concentration to the side with lower proton concentration. What kind of transport is this? A.simple diffusion B.facilitated diffusion C.active transport
B.facilitated diffusion
https://d1py7umku9kunm.cloudfront.net/assets/4531216/Blankenship_green-sulfur.jpg The image shows an energy diagram of electron flow in a bacterium that has only a Type I photosystem. What is the ultimate source of electrons in this diagram? A.water molecules B.hydrogen sulfide C. oxygen molecules D.sunlight E. carbon dioxide
B.hydrogen sulfide
What metabolic pathway defect(s) could cause lactic acid and pyruvate to build up? Choose all that apply. A. defect in glycolysis B. defect in the citric acid cycle C. defect in pyruvate oxidation D. defect in reduction of pyruvate to lactic acid E. defect in the mitochondrial electron transport chain
C and E C. defect in pyruvate oxidation E. defect in the mitochondrial electron transport chain Defect in pyruvate oxidation will result in accumulation of pyruvate, which will then be converted to lactic acid via the lactic acid fermentation pathway. A defect in the ETC will prevent regeneration of NAD+ from NADH; high NADH and low NAD+ then cause pyruvate to be fermented to lactic acid.
During glycolysis, for each mole of glucose oxidized to pyruvate A. Net 6 moles of ATP are produced. B. 4 moles of ATP are used, and 2 moles of ATP are produced. C. 2 moles of ATP are used, and 4 moles of ATP are produced. D. 2 moles of ATP are used, and 2 moles of ATP are produced. E. net 4 moles of ATP are produced.
C. 2 moles of ATP are used, and 4 moles of ATP are produced.
The biomass (dry weight) of a tree comes mostly from: A. Soil B. Water C. Air D. Sunlight
C. Air
The conversion of arachidonic acid to prostaglandin H2 by cyclooxygenases occurs spontaneously. This reaction is: A. An endergonic reaction, releasing free energy B. An endergonic reaction, absorbing free energy C. An exergonic reaction, releasing free energy D. An exergonic reaction, absorbing free energy
C. An exergonic reaction, releasing free energy
https://d1py7umku9kunm.cloudfront.net/assets/177722/calvincyclemanip.png If CO2 is unavailable, then: A. Compound X and 3PG will both increase B. Compound X will increase, 3PG decrease C. Compound X will decrease, 3PG increase D. Compound X and 3PG will both decrease
C. Compound X will decrease, 3PG increase
https://d1py7umku9kunm.cloudfront.net/assets/177722/calvincyclemanip.png If light is cut off, then: A. Compound X and 3PG will both increase B. Compound X will increase, 3PG decrease C. Compound X will decrease, 3PG increase D. Compound X and 3PG will decrease
C. Compound X will decrease, 3PG increase
The most common mutation in patients with severe cystic fibrosis disease is a 3-nucleotide deletion in the CFTR gene. This mutation produces a CFTR protein that is missing one amino acid, phenylalanine at the 508th amino acid position (Phe508; aka F508). In normal CFTR protein, if Phe508 is not in a transmembrane domain, then this hydrophobic amino acid is most likely... (select all that apply) A.On the surface of the protein interacting with the aqueous environment B. On the exterior of the folded protein domain where it interacts with the polar head groups of the membrane lipids C. In the interior of the folded protein where it interacts with other hydrophobic amino acid side chains
C. In the interior of the folded protein where it interacts with other hydrophobic amino acid side chains
If entropy always increases, then how do living organisms create macromolecules, cells, and complex higher-order structures? A. The laws of thermodynamics do not apply to living organisms. B. Living organisms use energy from the sun to accomplish the work of decreasing entropy. C. Living organisms use energy to decrease their own entropy, but generate waste heat that increases the total entropy of the organism and its environment. D. Living organisms convert light energy or chemical energy into organic matter. E. The increase in entropy as the organism grows is balanced by a decrease in entropy of the universe
C. Living organisms use energy to decrease their own entropy, but generate waste heat that increases the total entropy of the organism and its environment.
The chemical equation for respiration of a molecule of glucose is: C6H12O6 + 6O2 -> 6CO2 + 6 H2O. This is the same reaction as when a marshmallow catches fire and burns. In this oxidation-reduction reaction, which molecule(s) is(are) reduced? A.The carbon atoms of sugar are reduced B.The hydrogen atoms of sugar are reduced C. Molecular oxygen is reduced D. All of the above E. None of the above
C. Molecular oxygen is reduced
What is a product that is produced by both fermentation reactions (lactic acid fermentation or ethanol fermentation) and the electron transport chain? A. NADH B. pyruvate C. NAD+ D. carbon dioxide E. ATP
C. NAD+
Photosystem I absorbs light energy and gives electrons to A.the electron transport chain in the thylakoid membrane B. the ATP synthase in the thylakoid membrane C.NADP+ to make NADP D. to oxygen to make water E.to oxidized photosystem II
C. NADP+ to make NADP
Which of the following is produced during the citric acid cycle? A. Acetyl-coA B. Pyruvate C. Reduced electron carriers D. Lactic acid
C. Reduced electron carriers
https://d1py7umku9kunm.cloudfront.net/assets/161857/osmosis.png If an algal cell isolated from seawater is transferred to fresh water, the algal cell will initially A. lose water and decrease in volume B. stay the same - neither absorb nor lose water C. absorb water and increase in volume
C. absorb water and increase in volume
The input(s) into the citric acid cycle are: A. citric acid, NAD+, ADP, inorganic phosphate. B. pyruvate, NAD+, ADP, inorganic phosphate. C. acetyl CoA, NAD+, ADP, inorganic phosphate. D. acetyl CoA, ATP, NADH, H+,. E. CO2, ATP, NADH
C. acetyl CoA, NAD+, ADP, inorganic phosphate.
In mammalian cells, a Na+/K+ ATPase hydrolyzes ATP to ADP and Pi and uses the energy to pump Na+ (sodium) ions from the cytosol to the extracellular medium. At the same time, it pumps K+ (potassium) ions into the cytosol from the extracellular medium. As a result, the cytosol has low Na+ and high K+, whereas the extracellular medium has high Na+ and low K+. This type of Na+ transport is_____ A. simple diffusion B.facilitated transport C. active transport D.facilitated diffusion
C. active transport
The phosphate transport system in bacteria imports phosphate into the cell even when the concentration of phosphate outside the cell is much lower than inside. Phosphate import depends on energy provided by a pH gradient across the membrane. Phosphate transport is an example of: A. passive diffusion B. facilitated diffusion C. active transport D. osmosis
C. active transport
Detailed analysis of the damaged cells showed that ATP levels in the mitochondria were very low. Levels of pyruvate and acetyl coenzyme A (CoA) were normal. You begin to suspect a malfunction of a specific cellular metabolic pathway and so you request a more detailed analysis of the sub-cellular components of the affected cells from the autopsy. The levels of key metabolites are reported below: https://d1py7umku9kunm.cloudfront.net/assets/5301906/7deaths_metabolites.png In your groups, discuss the roles of each of these metabolites in cellular respiration, and whether they are substrates or products of which pathways. In LC, submit your answer to the following question: What cellular process or pathway is abnormal in these patients, based on these metabolite levels? A.glycolysis B.citric acid cycle C.electron transport chain D.pyruvate oxidation
C. electron transport chain C What stands out from this table is that the NAD+/NADH ratio is abnormal in the dead patients. Given the information on mitochondrial damage, this implicates the electron transport chain for failure to cycle NADH to NAD+
How do mitochondria maintain a supply of NAD+ to run pyruvate oxidation and the citric acid cycle? C. mitochondria oxidize NADH to NAD+ by reducing the electron transport chain B. mitochondria oxidize NADH to NAD+ by reducing pyruvate to lactic acid D. mitochondria oxidize NADH to NAD+ by reducing the ATP synthase A. mitochondria oxidize NADH to NAD+ by reducing pyruvate to ethanol E. mitochondria oxidize NADH to NAD+ by reducing carbon dioxide to make carbohydrates
C. mitochondria oxidize NADH to NAD+ by reducing the electron transport chain
The electron transport chain in bacteria is located A. in their mitochondrial inner membrane B. in their mitochondrial outer membrane C. on their plasma membranes D. in the cytoplasm E. in the nucleoid
C. on their plasma membranes!!!!!
What data in the autopsy seems inconsistent with hypoxia as the immediate cause of death? A. tissue sections showing massive cell death B. staining with dyes showing major mitochondrial damage C. oxygen levels in the patients' blood at 110 mm Hg
C. oxygen levels in the patients' blood at 110 mm Hg
In a eukaryotic cell, secreted proteins and integral plasma membrane proteins are synthesized by___ A. free cytoplasmic ribosomes B. ribosomes in the mitochondria C. ribosomes docked to the rough ER D. ribosomes inside the nucleus E.ribosomes docked to the plasma membrane
C. ribosomes docked to the rough ER
Which of these shows the correct order of a secreted protein trafficking through a cell, from its site of synthesis to exit from the cell? A. smooth ER -> rough ER -> plasma membrane B. smooth ER -> Golgi -> rough ER -> plasma membrane C. rough ER -> smooth ER -> Golgi -> plasma membrane D. rough ER -> smooth ER ->plasma membrane E. Golgi -> smooth ER -> rough ER -> plasma membrane
C. rough ER -> smooth ER -> Golgi -> plasma membrane
Some photosynthetic bacteria have only photosystem I, whereas cyanobacteria have both photosystems I and II. To determine whether a photosynthetic bacterium has only photosystem I or has both photosystem I and photosystem II, one should___ A.do experiments to generate an action spectrum. B. test for ability to reduce carbon. C. test for production of O2. D. determine if they have thylakoids in the chloroplasts. E. test for production of ATP. F. test for ability to reduce NAD+ or NADP+.
C. test for production of O2.
Which of these eukaryotic organelles is NOT part of the endomembrane system, nor derived from the endomembrane system? A.Golgi vesicles B. rough ER C.smooth ER D.mitochondria E. nuclear envelope F. lysosomes G.chloroplasts H.plasma membrane
D and G D.mitochondria G.chloroplasts
Which of the following is NOT a difference between C3 and C4 plants? A. The first product of carbon fixation is a 3-carbon molecule in C3 plants and a 4-carbon molecule in C4 plants B. C3 plants, but not C4 plants, experience extensive oxygenation by Rubisco (photorespiration) C. C4 plants have a different leaf anatomy, with photosynthetic bundle sheath cells D. C3 plants have Rubisco; C4 plants lack Rubisco and use PEP carboxylase instead E. C4 plants are better adapted for hot, dry environments than C3 plants
D. C3 plants have Rubisco; C4 plants lack Rubisco and use PEP carboxylase instead
Which of the following is NOT one of the six major elements that make up biological macromolecules? A. Hydrogen B. Sulfur C. Phosphorus D. Calcium E. Nitrogen
D. Calcium
What is true about all lipids in all cells? Select all that apply. A. Are made from glycerol and fatty acids B. Contain nitrogen C. Have low energy content D. Do not dissolve well in water E. Contain phosphate
D. Do not dissolve well in water By definition, lipids do not dissolve well in water. Not all lipids are phospholipids (sterols and triglycerides, for example), and not all phospholipids have fatty acids (archaea have phospholipids with isoprenoid chains).
https://d1py7umku9kunm.cloudfront.net/assets/177810/Chloroplast_structure.png Where in plant cells is the Calvin cycle located? A. In the chloroplast thylakoid lumen B. In the cytoplasm C. In the mitochondrial matrix D. In the chloroplast stroma E. In the chloroplast thylakoid membrane
D. In the chloroplast stroma
Which of the following is/are ONLY defined by shared physical properties (rather than a polymer defined by shared chemical structure). A. RNA B. DNA C. Glycans D. Lipids E. Proteins
D. Lipids
What molecule is a common input for (and used by) glycolysis, pyruvate oxidation, and the citric acid cycle? A. ADP B. Pyruvate C. Glucose D. NAD+ E. O2
D. NAD+
Which of the following is true of RNA vs DNA? A. DNA is a double-stranded helix; RNA is single-stranded and linear with no 3D structure B. DNA has four nucleotides; RNA has three C. RNA and DNA are chemically identical except that RNA contains uracil while DNA contains thymine D. None of these are correct
D. None of these are correct
Cyclooxygenases increase the rate of the reaction by A. Reducing the free energy of the products B. Increasing the free energy of the reactants C. Providing activation energy to the reactants D. Providing a transition state with lower activation energy E. Reacting with arachidonic acid
D. Providing a transition state with lower activation energy
One type of uptake of glucose from the intestine into the bloodstream depends on the Na+ gradient across the intestinal epithelial cell membrane. A molecule of glucose is co-transported with Na+ ions down the concentration gradient of Na+. Recall that cells establish and maintain Na+ ion gradients across their plasma membranes by the action of the Na+/K+ ATPase. This form of glucose uptake, dependent on the Na+ ion gradient across the membrane, is______ A. simple diffusion B. facilitated diffusion C. facilitated transport D. active transport
D. active transport
https://d1py7umku9kunm.cloudfront.net/assets/165553/enzyme-energy-diagram.png Which energy change labeled by a lower case letter (a-e) would be the same in both the enzyme-catalyzed and uncatalyzed reactions? A. a B. b C. c D. d E. e
D. d
In cells, the pathway of electrons is: A. from food to the electron transport chain to NAD+ to oxygen B. from oxygen to the electron transport chain to NAD+ to food C. from food to NAD+ to the electron transport chain to ATP synthase D. from food to NAD+ to the electron transport chain to the terminal electron acceptor E. from food to NAD+ to the electron transport chain to ADP
D. from food to NAD+ to the electron transport chain to the terminal electron acceptor
Which of these amino acids would most likely be present in the transmembrane domains of aquaporin facing the fatty acid tails of the phospholipids? A. positively charged amino acid like lysine B. polar amino acid like serine C. negatively charged amino acid like glutamic acid D. hydrophobic amino acid like valine E.Any amino acid, with no preference
D. hydrophobic amino acid like valine
The tetrameric structure of an aquaporin complex is an example of what level of protein structure? A. primary structure B. secondary structure C. tertiary structure D. quaternary structure
D. quaternary structure
Some fatty acids, like palmitic acid, stimulate cyclooxygenase activity allosterically. This means that: A. Palmitic acid is a co-substrate that binds to the active site together with arachidonic acid B. Palmitic acid prevents inhibitors from binding to the active site C.Competitive inhibitors will be ineffective when palmitic acid is bound D.Palmitic acid binds to a different site than the substrate
D.Palmitic acid binds to a different site than the substrate
What defines a chemical element? A. The number of electrons the atom has B. The number of neutrons in the nucleus of the atom C. The sum of the number of protons and neutrons in the nucleus of the atom D.The number of protons in the nucleus of the atom
D.The number of protons in the nucleus of the atom
Brand X margarine melts at room temperature, while Brand Y stays solid. Brand Y probably has: A. More cis-unsaturated and polyunsaturated fatty acids B. Shorter chain fatty acids C. More trans-unsaturated fatty acids D.More hydrogenated fatty acids E. Both more hydrogenated fatty acids and more trans-unsaturated fatty acids
E. Both more hydrogenated fatty acids and more trans-unsaturated fatty acids
Patrick was diagnosed as having a genetic defect in the pyruvate dehydrogenase complex, which carries out pyruvate oxidation. Where is this complex located in human cells? A. Cytoplasm B. Mitochondrial intermembrane space C. Mitochondrial outer membrane D. Mitochondrial inner membrane E. Mitochondrial matrix
E. Mitochondrial matrix
Cyclooxygenase-1 and cyclooxygenase-2 have 60% identical amino acid sequences, similar activities, and both form homodimers. Therefore, these enzymes have the same A. Primary structure B. Secondary structure C. Tertiary structure D.All of the above E. None of the above
E. None of the above
Which of these pathways evolved most recently? A.Chemiosmotic ATP synthesis B. Glycolysis C.Citric acid cycle D.Oxygenic photosynthesis E.Aerobic respiration
E.Aerobic respiration
https://d1py7umku9kunm.cloudfront.net/assets/4531265/Blankenship_oxygenic.jpg This image shows an energy diagram of electron flow in cyanobacteria, which does oxygenic photosynthesis like chloroplasts. It has both a Type II and a Type I photosystem. What is the ultimate source of electrons for reduction of NADP+ to NADPH?
H2O
Lactate (lactic acid) and pyruvate accumulated in his blood. Lactic acidosis led to: Hyperventilation Muscle pain and weakness Abdominal pain and nausea
Hyperventilation Muscle pain and weakness Abdominal pain and nausea
How can you tell whether a photosynthetic bacterium has only a single type of photosystem, or 2 types of photosystems?
If it produces oxygen gas, it has 2 photosystems. Otherwise, it has only one. Photosynthetic bacteria that have only a Type I or a Type II photosystem cannot split water molecules to produce oxygen gas. Only cyanobacteria and chloroplasts, that have both Type II and Type I photosystems coupled together can split water molecules to generate oxygen gas. Another way to tell is to see if they require electron donors such a hydrogen sulfide to grow. Photosynthetic bacteria with only a Type I or a Type II photosystem cannot get electrons from water, so they need an electron donor such as hydrogen sulfide.
Which of the following statements about NAD+ or NADH are true? Select all true statements. a. NAD+ is the oxidized form b. NAD+ is reduced to NADH by electrons from organic carbon molecules c. NADH reduces ATP synthase d. NAD+ reduces the electron transport chain
a and b a. NAD+ is the oxidized form b. NAD+ is reduced to NADH by electrons from organic carbon molecules
The oxidation of glucose to CO2 and H2O is highly exergonic; ΔGo = -636 kcal/mole. Why doesn't glucose spontaneously combust? a. The glucose molecules lack the activation energy at room temperature b. The oxidation of glucose is not spontaneous c. CO2 has higher energy than glucose d. The formation of 6 CO2 molecules from one glucose molecule decreases entropy e. The water molecules quench the reaction
a. The glucose molecules lack the activation energy at room temperature
Which of the following observations are consistent with the endosymbiotic theory for the origin of mitochondria? C. mitochondria make their own ribosomes B. mitochondria have their own DNA D. mitochondrial DNA is circular A. mitochondria have two membranes E. mitochondrial DNA sequences are most similar to DNA sequences from a particular group of bacteria
a. mitochondria have two membranes b. mitochondria have their own DNA c. mitochondria make their own ribosomes d. mitochondrial DNA is circular e. mitochondrial DNA sequences are most similar to DNA sequences from a particular group of bacteria a,b,c,d,e
amino acids - monosaccharides- nucleotides -
amino acids - proteins monosaccharides - polysaccharides nucleotides - nucleic acids
https://d1py7umku9kunm.cloudfront.net/assets/749633/ETC-wikimedia.png What will happen to ATP production when oxygen becomes scarce? a. Increase b. Decrease c. Stay the same
b. Decrease When oxygen becomes limiting, as in hypoxia, the electron transport chain backs up, and the rate of proton pumping decreases. As a result, the proton gradient will be depleted by ATP synthase. Once the proton gradient becomes depleted (a matter of some seconds), it cannot provide sufficient energy for ATP synthesis.
https://d1py7umku9kunm.cloudfront.net/assets/749633/ETC-wikimedia.png What will happen to ATP production if the inner membrane becomes leaky to protons? A. Increase B. Decrease C. Stay the same
b. Decrease If the membrane becomes leaky to protons, then the proton gradient will dissipate. The electron transport chain will be pumping protons, but the protons recross the membrane through the leaks instead of through ATP synthase. Once the proton gradient becomes depleted, it cannot provide sufficient energy for ATP synthesis.
Which is the "better" enzyme? a. The enzyme with the higher Km b. The enzyme with the lower Km c. Km is not an informative measure of enzyme activity
b. The enzyme with the lower Km
https://d1py7umku9kunm.cloudfront.net/assets/749633/ETC-wikimedia.png What will happen to the proton gradient when oxygen becomes scarce? a. Increase b. Decrease c. Stay the same
b. decrease When oxygen becomes limiting, as in hypoxia, the electron transport chain backs up, and the rate of proton pumping decreases. As a result, the proton gradient will be depleted by ATP synthase.
You are now convinced that you know the cause of death for these victims and quickly report it back to the police as this is a very dangerous situation. After realizing that the electron transport chain was no longer functioning, you started to suspect poisoning and ran a blood test for various poisons that you knew affected the electron transport chain. The test of all seven patients came back positive for cyanide. Cyanide irreversibly binds to cytochrome c oxidase (CcOX) of the electron transport chain and prevents the transfer of electrons to oxygen, the final electron acceptor. In the presence of cyanide, what would happen to the proton gradient across the inner mitochondrial membrane? a. it would increase b. it would decrease c. it would stay the same
b. it would decrease With no electron flow, no protons will be pumped across the inner mitochondrial membrane. The pr
https://d1py7umku9kunm.cloudfront.net/assets/2883702/Collins_Fig1_edited.png Newborn babies have "brown fat" cells that make a mitochondrial inner membrane protein called UCP1, that acts as a channel for facilitated diffusion of protons. When this channel opens, what will be the effect on the proton gradient across the inner mitochondrial membrane? a. the proton gradient will increase b. the proton gradient will decrease c. the proton gradient will stay the same
b. the proton gradient will decrease Recall that respiration and the flow of electrons down the electron transport chain pumps protons across the mitochondrial inner membrane. This proton gradient generates a proton motive force that drives protons back across the membrane down their concentration gradient through a channel in ATP synthase to power ATP synthesis. If additional proton channels open in the membrane, the protons will flow down their concentration gradients through these channels, dissipating the proton gradient. Another way of saying it is that the membrane will have sprung leaks to allow protons to return across the membrane, decreasing the proton gradient.
https://d1py7umku9kunm.cloudfront.net/assets/5303727/atrazine_table1.png Table 1. Effect of herbicides on ATP production by isolated chloroplasts From the data in this table, how do these herbicides kill plants? a. they inhibit oxidative phosphorylation b. they inhibit photophosphorylation c. they inhibit cellular respiration d. cannot tell from the data provided
b. they inhibit photophosphorylation
https://d1py7umku9kunm.cloudfront.net/assets/1798925/enzyme-energy-diagram.png The reaction A+B → C+D is: a.Endergonic, deltaG is positive b.Exergonic, deltaG is negative c.At equilibrium d. irreversible e.Both exergonic and at equilibrium
b.Exergonic, deltaG is negative
https://d1py7umku9kunm.cloudfront.net/assets/184341/allosteric-regulation.png Which shows noncompetitive inhibition by an allosteric regulator? a b c
c
If life originated in deep sea thermal vents, then the first cells were probably: a. Aerobic chemotrophs b. Aerobic phototrophs c. Anaerobic chemotrophs d. Anaerobic phototrophs
c. Anaerobic chemotrophs
The electron transport chain in bacteria is located a. In their mitochondrial inner membranes b. In their mitochondrial outer membranes c. In their plasma membranes d. In the cytoplasm e. In the nucleoid
c. In their plasma membranes
A fish cell membrane will be more fluid at low temperature if it contains: A. More trans-unsaturated fatty acids b. Longer chain fatty acids C. More cis-unsaturated and polyunsaturated fatty acids D. Both A and B E.Both A and C
c. More cis-unsaturated and polyunsaturated fatty acids
The context for this and other questions in this module on cystifc fibrosis (CF) and the cystic fibrosis transmembrane conductor (CFTR) protein is provided in this blost post: Cystic fibrosis, a case study for membranes and transport. CFTR is a plasma membrane protein with multiple transmembrane domains. In what cellular compartment will the CFTR protein be synthesized? a. Cytoplasm b. Nucleus c. Rough endoplasmic reticulum d.Smooth endoplasmic reticulum e.Plasma membrane
c. Rough endoplasmic reticulum
https://d1py7umku9kunm.cloudfront.net/assets/1854821/Calvin_TLC5s.png 2-D TLCs of radiolabelled organic compounds, from http://5e.plantphys.net/article.php?ch=t&id=77 Explain the results seen after 30 sec of photosynthesis. What pathways use the newly fixed carbon? (feel free to look up some of these compounds if you don't know what they are).
carbohydrate synthesis (sugar phosphates & sucrose), amino acid synthesis (alanine, glycine, serine, aspartic acid), citric acid cycle (malic acid, citric acid)
What kind of amino acids would occur most frequently in the transmembrane domains of integral membrane proteins? a. amino acids with positively charged side groups b. amino acids with polar side groups c. amino acids with negatively charged side groups d. amino acids with hydrophobic side groups e. Any amino acid, with no preference
d. amino acids with hydrophobic side groups
All chemical reactions between atoms involves ____ a. the protons in the nucleus b. the neutrons in the nucleus c. any of the electrons in the atom d. only the valence electrons e. both protons in one atom and the electrons in the partner atom
d. only the valence electrons
Where would newly synthesized CFTR accumulate if microtubules were destroyed? https://d1py7umku9kunm.cloudfront.net/assets/2853270/Endomembrane_system_diagram.png
https://d1py7umku9kunm.cloudfront.net/assets/2853270/Endomembrane_system_diagram.png
Where would newly synthesized CFTR accumulate if formation of secretory vesicles was disrupted? https://d1py7umku9kunm.cloudfront.net/assets/2853270/Endomembrane_system_diagram.png
https://d1py7umku9kunm.cloudfront.net/assets/2853274/Endomembrane_system_diagram.png
Are living cells at chemical equilibrium? Yes No
no
non-polar covalent bond - electrons are shared equally between two atoms ionic bond - electrostatic attraction between ions of opposite charge polar covalent bond - electrons are shared between two atoms, but unequally hydrogen bond - weak electrostatic attraction involving a hydrogen atom with a weak positive charge and an electronegative atom with a weak negative charge non-polar covalent bonds, polar covalent bonds, and ionic bonds are all part of a continuous spectrum, from equal sharing of electrons (nonpolar covalent bonds) at one end, to a complete transfer of electrons (ionic bonds) at the other end, and with polar covalent bonds somewhere in between.
non-polar covalent bond - electrons are shared equally between two atoms ionic bond - electrostatic attraction between ions of opposite charge polar covalent bond - electrons are shared between two atoms, but unequally hydrogen bond - weak electrostatic attraction involving a hydrogen atom with a weak positive charge and an electronegative atom with a weak negative charge non-polar covalent bonds, polar covalent bonds, and ionic bonds are all part of a continuous spectrum, from equal sharing of electrons (nonpolar covalent bonds) at one end, to a complete transfer of electrons (ionic bonds) at the other end, and with polar covalent bonds somewhere in between.
Match the level of protein structure with the bonds responsible for stabilizing it: 1st choice covalent bonds between sequential amino acids 2nd choice hydrogen bonds between peptide backbone 3rd choice hyrdogen bonds, hydrophobic interactions, van der Waals, covalent, and ionic bonds between R groups and peptide backbone 4th choice hyrdogen bonds, hydrophobic interactions, van der Waals, covalent , and ionic bonds between multiple polypeptides
primary - covalent bonds between sequential amino acids secondary - hydrogen bonds between peptide backbone tertiary - hyrdogen bonds, hydrophobic interactions, van der Waals, covalent, and ionic bonds between R groups and peptide backbone quaternary - hyrdogen bonds, hydrophobic interactions, van der Waals, covalent , and ionic bonds between multiple polypeptides
Match the glycan molecule function with the type of glycosidic linkage: 1st choice alpha-1,4 2nd choice beta-1,4
storage - alpha-1,4 structure - beta-1,4
https://d1py7umku9kunm.cloudfront.net/assets/1781479/ATPsynthase_pHgradient.png Vesicles made from mitochondrial membranes containing ATP synthase were placed in an acidic solution to create a pH difference across the membrane that is of the same magnitude and direction as in mitochondria. Given ADP and phosphate, will ATP synthase make ATP? Indicate yes or no. yes no
yes