LS7A Final Exam Questions With Complete Solutions., Exams of Nursing

Download LS7A Final Exam Questions With Complete Solutions. and more Exams Nursing in PDF only on Docsity! LS7A Final Exam Questions With Complete Solutions. c and a Answer- In lab, a dialysis tube is filled with a 15% sucrose solution, sealed, and placed in an unlabeled beaker filled with clear liquid. The dialysis tube is made of a semipermeable membrane that allows the free passage of water, but is not permeable to sucrose. After 2 hours, the bag in the beaker decreases in size and becomes flaccid. This observation suggests that at the beginning of the experiment, the solution in the bag was __________________ compared to the solution in the beaker. a) isotonic b) hypertonic c) hypotonic Based on this observation, the contents of the beaker could have been: a) 25% sucrose. b) 5% sucrose. c) 15% sucrose. b Answer- Which of the following eukaryotic cell structures plays a role in protein trafficking and sorting? a) vacuoles b) the Golgi Apparatus c) mitochondria d) the endoplasmic reticulum c) lysosomes? d Answer- What describes the path traveled by a new protein as it is synthesized and released from the cell? a) cytosol → Golgi → ER → vesicle → plasma membrane → external environment b) nucleus → ER → Golgi → vesicle → plasma membrane → external environment c) nuclear envelope → ER → vesicle → Golgi → plasma membrane → external environment d) cytosol → ER → Golgi → vesicle → plasma membrane → external environment c) plasma membrane → ER → vesicle → Golgi → cytosol → external environment d Answer- Which one of the following molecules would MOST likely require a transport protein to cross the plasma membrane of a red blood cell? a) H20 b) CO2 c) O2 d) C6H12O6 F Answer- (T/F) Purified phospholipids gather together and form membranes only if the appropriate enzyme is present. b Answer- Which of the following is TRUE about the presence or absence of plasma membranes? a) Plant cells and bacterial cells have a plasma membrane, but animal cells do not. b) All cells have a plasma membrane. c) Plant cells and animal cells have a plasma membrane, but bacterial cells do not. d) Only animal cells have a plasma membrane. Plant cells and bacterial cells have a cell wall. c Answer- A beaker contains two solutions of glucose dissolved in water. The two solutions have different concentrations (measured by molarity, M) and are separated by a membrane that is permeable to water, but not to glucose. Side A has 0.3 M of glucose while side B has 0.8 M of glucose. The water is level on both sides at this time. Which of the following statements is TRUE? a) There will be net movement of glucose from B to A. b) The system will not reach equilibrium. c) The volume will increase in side B of the beaker. d) There will be net movement of water from B to A. c Answer- The sodium-potassium pump is an example of: a) a symporter. b) passive transport. c) an antiporter. d) None of the answer options is correct. c) channel-mediated diffusion. b Answer- Imagine that you are investigating the production of insulin in normal cells. You are using these cells to help determine the cause of faulty insulin production in other cells, in which insulin appears to be synthesized but fails to be secreted from the cell. You design experiments using three different pharmaceutical compounds to help pinpoint the trouble spot in the protein synthetic pathway. One compound blocks the movement of vesicles in the cytoplasm. Which of the following describes what you would expect to observe? a) an accumulation of insulin at the plasma membrane b) an accumulation of insulin in the Golgi apparatus c) an absence of insulin in the cell d) an accumulation of insulin in the cytosol b Answer- Imagine that you are investigating the production of insulin in normal cells. You are using these cells to help determine the cause of faulty insulin production in other cells, in which insulin appears to be synthesized but fails to be a, b, and c Answer- With which of the following is a signal-recognition particle (SRP) capable of interacting? (Select all that apply.) a) a ribosome b) an SRP receptor c) a signal sequence in a protein destined for the ER d Answer- The process of a vesicle fusing with the plasma membrane and depositing its contents into the extracellular space is referred to as: a) endocytosis. b) active transport. c) budding. d) exocytosis. e) bridging. a and e Answer- In which of the following regions of the cell can protein synthesis occur in eukaryotes? (Select all that apply.) a) cytoplasm b) nucleus c) Golgi apparatus d) lysosomes e) rough endoplasmic reticulum b Answer- If a mutation rendered the signal recognition particle nonfunctional, what would be the MOST obvious effect on the cell? a) All proteins normally secreted by the cell would remain partially formed and attached to the endoplasmic reticulum. b) All proteins normally secreted by the cell would remain in the cytosol. c) Proteins destined for the nucleus would remain in the cytosol. d) Translation would not be completed for most proteins. e) No proteins would arrive at their proper destinations within the cell. T Answer- (T/F) Amino acids with hydrophobic side chains are often found in the region of an integral membrane protein that spans the membrane. a Answer- RNA molecules are transported from the nucleus to the cytoplasm in eukaryotes through: a) nuclear pores. b) aquaporins. c) sodium-potassium pumps. d) budding off of the nuclear envelope. e) passive diffusion. d Answer- Imagine you have radioactively labeled a protein in the lumen of the endoplasmic reticulum. Where would you predict the labeled protein will end up? a) in the lumen of the Golgi apparatus b) outside the cell c) in the lumen of a vesicle d) All of these choices are correct. a Answer- Enzymes present in the lumen of the Golgi apparatus are responsible for modifying proteins and lipids. What is the likely origin of these enzymes? a) the rough endoplasmic reticulum b) the smooth endoplasmic reticulum c) free ribosomes d) the cytosol a Answer- Which of the following would NOT be synthesized on the endoplasmic reticulum? a) kinesin b) phospholipid c) Na+/K+ pump protein d) endorphin e) insulin a Answer- In a pulse-chase experiment that briefly labels newly- made phospholipids with a radioactive label, the label would be seen in these locations in the following order: a) Smooth ER --> Golgi --> secretory vesicles --> plasma membrane b) Smooth ER --> secretory vesicles --> Golgi --> plasma membrane c) Rough ER --> Golgi --> secretory vesicles --> plasma membrane d) Rough ER --> smooth ER --> Golgi e) Golgi --> secretory vesicles --> smooth ER --> plasma membrane c Answer- ATP provides energy for actin polymerization, which provides the force to push out the edge of a cell. What is the best statement for how the energy in ATP is used in actin polymerization? a) The ATP hydrolysis reaction is coupled to an endergonic chemical reaction to make the overall reaction exergonic (favorable) b) When ATP hydrolyzed, actin becomes phosphorylated, which causes it to have different conformations and stick to the ends of growing filaments c) Actin that binds ATP sticks to the ends of filaments whereas actin that binds ADP has a different protein conformation and leaves the ends of filaments d) The free energy that is released by ATP hyrdrolysis is used by the cell to make actin filaments e) When ATP hydrolyzes to ADP and Pi, the phosphate helps actin polymerize into filaments d Answer- In cells, the major job of the __________ cytoskeleton is changing and maintaining cell shape, whereas the major job of the __________ cytoskeleton is __________ a) microtubule, actin, cell movement b) intermediate, actin, movement inside cells c) actin, microtubule, cell structure and strength d) actin, microtubule, movement inside cells e) microtubule, kinesin, moving chromosomes c Answer- The sacred lotus plant can heat itself and maintain temperature. It?t does this by expressing and activating the AOX protein, which functions in the mitichondria. What is the best explanation for how AOX activity generates heat? a) lots of ATP's are hydrolyzed, uncoupled from endergonic reaction b) protons flow back down into the matrix is uncoupled from the ATP synthase c) electron flow is uncoupled from proton pumping d) cellular respiration stops and goes anaerobic, causing fermentation to start up e) electron flows through the AOX, generating additional friction b Answer- When a photon hits a chlorophyll molecule in an antenna complex, ________ moves toward the reaction center chlorophyll by __________. a) an electron, resonance transfer b) energy, resonance transfer c) an electron, oxidation/ reduction d) energy, fluorescence e) energy, oxidation/ reduction a Answer- In plants, sugars move from leaf cells into companion cells because a) protons are more concentrated outside the companion cells than inside b) sugar is more concentrated inside companion cells than outside c) protons are more concentrated inside companion cells than outside d) sugar moves in the phloem from source to sink via pressure differences e) companion cells use a sucrose pump that requires ATP to pimp sugar into companion cells b Answer- In plants, water moves through xylem toward the leaves because a) water potential is higher in leaves than in roots b) water potential is lower in air than in roots c) pressure potential is higher in leaves than in roots d) solute potential is higher in leaf cells than in the xylem e) solute potential in leaf xylem is lower than in root xylem a Answer- Assuming the stomata are open to the same degree, the rate of transpiration should __________ on a rainy day compared with a sunny day because the H2O concentration gradient from the inside to the outside of the leaf would _________. e) The melanophores in these tadpoles have partially functional or nonfunctional myosin that would normally transport organelles along microfilaments to the center of the cell. Which part of the cytoskeleton would you suggest investigating as a potential source of the faulty color adjustment in these tadpoles? a) microtubules b) microfilaments c) intermediate filaments b Answer- Myosin is a motor protein that associates with: a) intermediate filaments. b) microfilaments. c) microtubules. d) vimentin. d Answer- Dynein motor proteins use ATP to: a) carry vesicles along a microfilament within a cell in a minus-to-plus direction. b) carry vesicles along a microfilament within a cell in a plus-to-minus direction. c) slide along microfilaments to contract muscle cells. d) carry vesicles along a microtubule within a cell in a plus-to-minus direction. e) carry vesicles along a microtubule within a cell in a minus-to-plus direction b Answer- The cytoskeleton of animal cells includes: a) actin, microfilaments, and intermediate filaments. b) microtubules, microfilaments, and intermediate filaments. c) actin, microtubules, and intermediate filaments. d) tubulin, microfilaments, and intermediate filaments. e) microtubules and microfilaments. a, b, and c Answer- When stomata are open and a plant is transpiring normally, water moves from the soil into the root xylem: (Select all that apply.) a) in a flow that is ultimately driven by evaporation from the shoot. b) without the plant doing any additional work on the fluid. c) due to a force generated by the partial dehydration of cell walls in leaves. d) due to the action of ATP driven pumps in the endodermis. a Answer- Water is transported from the soil to the leaves in the: a) xylem. b) cuticle. c) phloem. d) stomata. e) parenchyma. c Answer- Unlike how animals circulate their blood, trees transport water: a) by direct expense of metabolic energy. b) in a closed, recirculating system. c) in an open system driven by evaporation. d) without specialized tissues for long-distance transport a Answer- The structure(s) that allow(s) gasses, such as CO2, to diffuse into and out of a leaf is/are the: a) stomata. b) veins. c) vascular bundles. d) cuticle. e) mesophyll cells. d Answer- What causes water to flow from the soil to the leaves? a) Water is pulled up through the xylem due to capillary forces in the xylem. b) Water exits the stomata due to capillary forces. c) Water is pushed up the xylem due to high turgor pressure in the roots. d) The partial dehydration of mesophyll cell walls creates a force that pulls water into the leaf. T Answer- (T/F) A companion cell supports a sieve element by performing specific cellular processes. d Answer- Xylem transports _____, whereas phloem transports _____. a) sugars; starch b) sugars; minerals c) water; minerals d) water; sugars e) sugars; water a, b,and d Answer- Which of the following would be considered a carbohydrate sink in vascular plants? (Select all that apply.) a) stems b) flowers c) mature leaves d) roots a Answer- Vascular plants store most carbohydrate reserves as: a) starch. b) lipids. c) glycogen. d) glucose. e) sucrose. d Answer- Why may young leaves that are just emerging from the bud be considered "sinks" for phloem transport? a) They produce carbohydrates through photosynthesis. b) They do not have developed sieve tubes. c) The sucrose concentration is too high. d) They consume more carbohydrates than they produce. b Answer- Which of the following is TRUE of transport in phloem? a) It only occurs from leaves to roots. b) It is driven by turgor pressure. c) It occurs from sink to source. d) It is usually a passive process. e) It moves materials down the plant body. c Answer- Which of the following processes spontaneously occur without the plant having to expend metabolic energy? a) DNA replication b) the movement of ions into guard cells c) movement of water through the xylem d) nutrient transport across endodermal cells c Answer- In which direction would phloem sap flow if there were a greater concentration of sucrose molecules in the root phloem compared with the leaf phloem? a) There would not be enough turgor pressure to move the sap. b) from leaf to root c) from root to leaf d) in the opposite direction to xylem flow F Answer- (T/F) A benefit of starch being the storage molecule in plants is that starch is easy for plants to move throughout the plant body. a Answer- Plants lose a great deal of water from their leaves in a process referred to as: a) transpiration. b) transfection. c) transformation. d) transduction. c Answer- If water molecules (H2O) suddenly stopped forming hydrogen bonds with each other, how would water transport in vascular plants change (if at all)? a) It would remain the same, because H2O molecules also form oxygen bonds. b) It would remain the same, because water transport only depends on osmosis. b Answer- Where is the photosynthetic electron transport chain located in plant cells? a) in the inner membrane of the chloroplast b) in the thylakoid membranes of the chloroplast c) in the outer membrane of the chloroplast d) in the stroma of the chloroplast c Answer- Two petri dishes of radish seeds are prepared as follows: a disk of absorbent, but otherwise inert, filter paper is placed in the bottom of each dish and 5 mL of distilled water are added to each disk, then 2 grams of dry radish seeds are spread over each moist disk. One dish is put in a dark cupboard and the other is put on a sunny windowsill. The investigator checks the dishes daily and adds water equally as needed. Seeds in both treatments germinate within 2 days. At the end of 10 days, the plant material on each petri plate is dried and weighed. The results are: - starting dry weight 2.00 g - sunny windowsill 2.25 g - dark cupboard 1.75 g What is the MOST likely explanation for why the dark-grown seedlings lost biomass? a) Cellular respiration and ATP synthesis needed for growth does not occur as efficiently in plants in the dark as in plants exposed to light. b) The metabolism in the cells of the seedlings increased to compensate for the lack of light energy. c) Cellular respiration in the cells of the seedlings consumed the starch and oils present in the seeds as sources of energy. a Answer- Which of the following does NOT happen in the Calvin cycle of photosynthesis? a) reduction of NADP+ to NADPH b) hydrolysis of ATP to ADP c) the incorporation of CO2 into an organic molecule by RUBISCO d) the synthesis of a three-carbon carbohydrate e Answer- During photosynthesis, _____ is reduced to _____. a) oxygen; water b) water; carbon dioxide c) sugar; oxygen d) carbon dioxide; oxygen e) carbon dioxide; sugar b Answer- During photosynthesis, _____ is reduced to _____. a) carbon dioxide; oxygen b) carbon dioxide; triose phosphate c) water; carbon dioxide d) triose phosphate; oxygen e) oxygen; water c Answer- A new experimental pesticide is being tested by a large agricultural chemical company. An unfortunate side effect in plants treated with this new product is a decrease in NADPH production in the chloroplasts. (Interestingly, reduction of NAD+ to NADH in the mitochondria is unaffected.) Given this observation, which of the following would you expect to observe in the chloroplasts of these plants? a) an increase in 3-phosphoglycerate production and an increase in RuBP production b) an increase in glyceraldehyde-3-phosphate production c) an increase in 3-phosphoglycerate levels and a decrease in RuBP production d) a decrease in 3-phosphoglycerate levels and an increase in RuBP production d Answer- The reducing agent during the Calvin cycle is: a) FADH2. b) oxygen. c) NADH. d) NADPH. e) ATP. b Answer- The enzyme called rubisco: a) breaks a 1-carbon molecule off of a 6-carbon molecule. b) connects a 1-carbon molecule to a 5-carbon molecule. c) breaks a 3-carbon molecule into 1-carbon and 2-carbon molecules. d) connects two 3-carbon molecules into a 6-carbon molecule. e) connects a 3-carbon molecule to a 5-carbon molecule. a Answer- Which of the following CORRECTLY describes the role of rubisco in the Calvin cycle? a) Rubisco incorporates CO2 from the atmosphere into an organic molecule. b) Rubisco uses NADPH to reduce 3-phosphoglycerate to a three-carbon sugar. c) None of the other answer options is correct. d) Rubisco uses ATP to regenerate RUBP. d Answer- Which of the following are products of the light-dependent reactions of photosynthesis that are required by reactions in the Calvin cycle? a) NADP+ and oxygen b) Water and NADPH c) ATP and oxygen d) ATP and NADPH b Answer- A new experimental pesticide is being tested by a large agricultural chemical company. An unfortunate side effect in plants treated with this new product is a decrease in ATP production in the chloroplasts. (Interestingly, production of ATP in the mitochondria is unaffected.) Given this observation, which of the following would you expect to be DIRECTLY affected by the new pesticide? a) the carboxylation of RuBP by rubisco b) the synthesis of triose phosphates from 3-phosphoglycerate c) the oxidation of RuBP by rubisco d) the transport of electrons along the photosynthetic electron transport chain b Answer- In a thylakoid membrane, absorbed light energy is passed from one chlorophyll molecule to another until it is: a) released as fluorescence. b) passed to a reaction center. c) All these choices are correct. d) both dissipated as heat and released as fluorescence. e) dissipated as heat. c Answer- Which one of the following statements BEST represents the relationship between cellular respiration and photosynthesis? a) Respiration occurs only in animals and photosynthesis occurs only in plants. b) Respiration stores energy in organic molecules, while photosynthesis releases it. c) Photosynthesis stores energy in organic molecules, while respiration releases it. d) Photosynthesis reverses the biochemical pathways of respiration. e) Photosynthesis occurs only during the day and respiration occurs only at night. a Answer- Leaves absorb the LEAST amount of light in the _____ range of the visible spectrum. a) green b) blue c) orange d) yellow e) violet d Answer- Light energy is converted to chemical energy in the: a) mitochondria. b) cytoplasm. c) central vacuole. d) thylakoid membrane. e) nucleus. F Answer- (T/F) In animal cells, most ATP synthesis takes place in mitochondria, but in plant cells, most of the ATP used by plant cells is made in the chloroplasts. c Answer- What is the INITIAL carbon input in the Calvin cycle? C) There would be no change in the growth of balsam firs b Answer- According to the "bottom up" hypothesis, how would removal of wolves influence the growth of balsam fir trees? A) Growth of balsam firs would increase B) Growth of balsam firs would decrease C) There would be no change in the growth of balsam firs c Answer- How have historical growth rates of balsam fir been measured on Isle Royale? A) Diameter of tree trunks B) Number of trees C) Tree-ring analysis a Answer- If the numbers of organisms in these lakes are controlled by "bottom up" primary productivity, which lake should have more bass per acre? A. Peter lake (on left) B. Paul lake (on right) C. Both should be equal D. Need more information to be able to answer Q. b Answer- U of Wisconsin researchers added some largemouth bass to Peter Lake (on left). "Top down" control was exerted by the bass. What did they observe later on? (Paul Lake was a control) A. Algae increased B. Algae decreased C. Algae stayed the same D. Need more information to be able to answer Q Matter is moved as a cycle among the trophic levels. Answer- How does matter move between trophic levels? respiration, growth, or excretion Answer- When consumers eat food, what happens to the ENERGY that was in the food? a Answer- How can the witch get more calories? A. eat the cupcake and Hansel now B. feed the cupcake to Hansel to fatten him up, then eat him next week energy gets moved between trophic levels while matter is cycled among trophic levels. Answer- How does the movement of energy in an ecosystem compare with the movement of matter (i.e., nutrients like N or C)? d Answer- Consider all of the food that an organism eats. A fraction is egested, and the rest is _____. A) respired B) consumed C) produced D) assimilated E) no way to know d Answer- Another term for "net production" is _______________. A) primary production B) respiration C) assimilation D) biomass E) secondary consumer a) 2.6 b) We should pay attention because this indicates how efficient our consumption is. Answer- Median human trophic level. The global food chain scale goes from 1 (autotrophs) to 5.5 (top predators such as polar bears or orcas). a) Where are humans on this scale? b) Why should we pay attention to this data? F Answer- 1 lb. of eagle has less energy in it than 1 lb. of lemming T or F c Answer- If an acre of farmland can produce enough food to feed 10 people each year, how many people can that acre feed if the grain is used as animal food first, then the people ate the animals? (Remember this figure: 10 people/acre) A) 100 people/yr B) 10 people/yr C) 1 person/yr D) 0.1 person/yr a Answer- There are 3.7 billion acres of land on the earth that can grow food plants. If all humans were vegetarians, how many people could be fed each year? A) 37 billion B) 3.7 billion C) 370 billion D) 0.37 billion b Answer- There are 3.7 billion acres of land on the earth that can grow food plants. If all humans ate only meat, how many people could be fed each year? A) 37 billion B) 3.7 billion C) 370 billion D) 0.37 billion plant breeding, mechanization, irrigation, pesticides, and fertilizers Answer- What advances are associated with the Green Revolution? produced more food Answer- What was the overall outcome of the Green Revolution? Increased growth rates (yield = quant per acre), pest resistant, drought tolerance, and salt tolerance Answer- what were four effects of plant breeding? economies of scale and monocrops Answer- what were two effects of mechanization? organic and synthetic Answer- what are the two types of fertilizers? d Answer- What is not part of the green revolution? A) plant breeding B) mechanization C) irrigation D) pesticides E) fertilizers B) -2 kcal/mol, will be favorable C) +2 kcal/mol, will NOT be favorable D) +2 kcal/mol, will be favorable E) -12 kcal/mol, will be favorable c Answer- Chemical bonds carry ________ when the electrons are shared _________ between atoms. A) more activation energy, unequally B) higher charges, equally C) more free energy, equally D) more potential energy, unequally E) more free energy, unequally e Answer- Why does the hydrolysis of ATP release energy? Choose the BEST answer. A) The negative charges of the phosphates of the ATP attract each other B) The electrons in free phosphate have more resonance states than when the phosphate is a part of ATP. C) ADP and free phosphate contain more free energy than ATP and water. D) A and B E) A, B, and C c Answer- When human muscles are exercised and oxygen are depleted, the muscles can continue to run glycolysis because _________. A) NADH reduction is coupled to pyruvate oxidation to generate CO2 and acetyl-CoA B) lactic acid is produced and is used as a substitute in glycolysis C) NADH oxidation is coupled to pyruvate reduction to regenerate NAD+ D) NADH reduction is coupled to pyruvate oxidation to regenerate NAD+ E) fermentation converts NADH to ATP a Answer- Which part of respiration does NOT take place in the mitochondria in eukaryotic cells? A) glycolysis B) pyruvate oxidation C) citric acid cycle D) None of these parts take place in the mitochondria in eukaryotic cells? E) All of these parts take place in the mitochondria b Answer- If you look at one of the chemical reactions in respiration, how can you tell that the reaction is an oxidation reaction? A) ATP is produced B) NADH is produced C) NAD+ is produced D) a kinase enzyme catalyzes the reaction E) ATP is one of the reactants a Answer- Nitrogen (N) is more E.N. than hydrogen (H). Which of the following is a correct statement about the atoms in ammonia (NH3)? a. Each H atom has a partial positive charge: the N atom has a partial negative charge b. The N atom has a partial positive charge; each H atom has a partial negative charge c. Ammonia has an overall positive charge d. Ammonia has an overall negative charge e. There are covalent bonds between the hydrogen atoms and polar bonds betw. each H atom and the N atom e Answer- Bonds between 2 atoms that are equally E.N. are ______ a. polar covalent bonds b. ionic bonds c. H bonds d. van der Waals interactions e. nonpolar covalent bonds a Answer- Which of the following statements about energy is NOT TRUE? a. it can be created by cellular respiration b. 1000 dice in the floor (all showing 6) has more of it than 1000 dice in the floor (~1/6 showing 1, ~1/6 showing 2, ~1/6 showing 3, etc.) c. a solution of 10mM Na+ ions on one side of a cell mem. contains more of it than a solution of 2 mM Na+ on the other side of the cell membrane d. it can transform from potential to kinetic and back again e. it is the capacity to do work c Answer- Why are polymerization reactions endergonic? polymerization reactions _____. a. are at equilibrium b. release energy c. reduce entropy d. release heat, making the reactant monomers move faster d Answer- A major enzyme involved in protein digestion is _____ a. pancreatic lipase b. amylase c. lingual lipase d. pepsin a Answer- When a woman has her gallbladder removed, she should probably reduce her consumption of ______ a. fats b. proteins and carbs c. carbs d. proteins a Answer- The pancreas is involved in the digestion of _____ i) protein ii) fat iii) carbs a. i, ii, iii b. i, iii c. iii d. ii, iii e. i, iii b Answer- A person with Type I Diabetes has no insulin-producing cells in their pancreas. Which of the following is CORRECT? a. this person should receive an insulin injection if she hasn't eaten a meal in a long time, so that glucose levels will elevate in the blood b. if untreated, this person's liver and muscle cells cannot import glucose c. if untreated, this person's small intestine cannot digest polysaccharides d. the insulin receptors on this person's liver cells are insensitive to the presence of insuli a Answer- During a laboratory experiment, you discover that an enzyme-catalyzed reaction has a ΔG of -20 kcal/mol. If you double the amount of enzyme in the reaction, what will be the ΔG for the new reaction? a. -20 b. -40 c. between -20 and -40 d. +20 e. 0 d Answer- In chemical reactions, changes in both enthalpy (the bond energy) and entropy can influence which direction the reaction will proceed. This makes it difficult to predict which direction a chemical reaction will proceed spontaneously. Which of the following is the BEST statement? a. the change in ENTHALPY is the best indicator: if the reactants have LESS free energy than the products, the reaction is endothermic and will go forward b. the change in FREE ENERGY is the best indicator: if the reactants have LESS entropy than the products, the reaction will go forward c. the change in ENTROPY is the best indicator: if the reactants have LESS entropy than the products, the reaction will go forward because entropy always increases in the universe d. the change in FREE ENERGY is the best indicator: if the reactants have MORE free energy than the products, the reaction will go forwards a. NAD+ b. ATP c. pyruvate d. ATP, NAD+, and pyruvate e. ATP and pyruvate a Answer- In glycolysis, a 3-carbon molecule called PEP gets its phosphate removed, and PEP becomes pyruvate. We could write the reaction like this: PEP ---> pyruvate + Pi ΔG= -10 kcal/mol. Now, ADP +Pi ---> ATP with ΔG = +7.3 kcal/mol. If the reactions are coupled together, ______ a. the energy released by the first reaction is enough to drive ATP formation b. the coupled reaction would be endergonic c. pyruvate becomes more reduced d. the energy released by the second reaction is enough to drive the production of pyruvate e. ATP gets consumed by substrate-level phosphorylation a Answer- When human muscles are exercised and oxygen is depleted, the muscles can continue to run glycolysis because ____ a. NADH oxidation is coupled to pyruvate reduction to regenerate NAD+ b. NADH reduction is coupled c. lactic acid is produced and is used as a substitute for glucose in glycolysis d. NADH reduction is coupled to pyruvate oxidation to regenerate NAD+ e. fermentation converts NADH to ATP e Answer- In euks, pyruvate is made in the ______ and acetyl-CoA id made in the _____ a. matrix, matrix b. cytosol, inner mem of mitochondria c. cytosol, intermembrane space d. cytosol, cytosol e. cytosol, cytosol losing electrons/ losing protons (H+) Answer- A molecule that is more oxidized means _______ b Answer- During the citric acid cycle, the production of CO2 is the result of the ______ of the intermediate compounds of the citric acid cycle coupled to the production of ______ a. reduction; ATP b. oxidation; NADH c. oxidation; GTP d. oxidation; ATP e. reduction; NADH a Answer- Electron flow through the electron transport chain releases energy. This energy is used MOST DIRECTLY ______ a. to pump protons OUT the mitochondrial matrix, making the intermembrane space more acidic b. to reduce NAD+ c. by kinase to make ATP from ADP and Pi d. to make CO2 as a by-product of respiration e. to make O2 b Answer- Two members of the E.T.C: when Cyt b is reduced and when FES is oxidized, an electron leaps from Cyt b to FeS. Why does this happen? a. FeS has an active site witha perfect shape to fit an electron b. FeS has a stronger attraction for that electron than Cyt b does. The rxn releases E c. Cyt b has a stronger attraction for that electron than FeS does. The rxn releases E d. the electron is getting pushed from behind by more electrons coming from NADH molecules e. the electron knows that oxygen is waiting at the end of the line, and it's very favorable for electrons to move toward oxygen a Answer- Which of the following represents a plausible pathway of ELECTRONS through the process of cellular respiration? (focus on order) a. glucose - pyruvate - acetyl-CoA - FADH2 - O2 b. glucose - NADH - ETC - acetyl-CoA - O2 c. glucose - pyruvate - ETC - NADH - acetyl-CoA - O2 d. glucose - acetyl-CoA - NADH - ETC - CO2 e. glucose - CO2 - FADH2 - ETC - O2 a Answer- Which of the following represents a plausible pathway of a CARBON ATOM through the process of cellular respiration? a. glucose---pyruvate---CO2 b. glucose---acetyl-CoA---pyruvate---citric acid---CO2 c. glucose---pyruvate---ETC---O2 d. glucose---pyruvate---ETC---O2 e. glucose---CO2---acetyl-CoA---citric acid---CO2 a Answer- Which of the following represents a plausible pathway of a CARBON ATOM through the process of cellular respiration? a. glucose---pyruvate---CO2 b. glucose---acetyl-CoA---pyruvate---citric acid---CO2 c. glucose---pyruvate---ETC---O2 d. glucose---pyruvate---ETC---O2 e. glucose---CO2---acetyl-CoA---citric acid---CO2 d Answer- Which represents a plausible pathway of POTENTIAL ENERGY through the process of cellular respiration? a. glucose---CO2---pyruvate---ATP b. glucose---acetyl-CoA---NADH---ETC---CO2 c. glucose---proton gradient--- NADH--- ATP d. glucose---ETC----O2----ATP c Answer- In which stage(s) of cellular respiration do you see CO2 production? 1= glycolysis 2=pyruvate oxidation 3=citric acid cycle a. 3 b. 1, 2, and 3 c. 2 and 3 d. 1 and 2 e. 1 and 3 b Answer- Which statement correctly compare cellular respiration in bacteria and euks? a. the production of ATP through oxidative phosphorylation happens in the mitochondrial matrix of both bacteria and euks b. cellular respiration is very similar in bacteria and euks, except it's the bacteria plasma membrane that contains the ETC and ATP c. bacteria rely exclusively on fermentation to make ATP while euks can use either fermentation or oxidative phosphorylation, depending on the condition d. euks use NAD+/NADH to carry electrons, whereas bacteria use FAD/FADH2 e. the citric acid cycle takes place in the mitochondrial matrix in euks, whereas it takes place outside of bacteria cells e Answer- In the pathways of aerobic respiration, O2 is not DIRECTLY involved in any of the reactions prior to the ETC. Why then does the Citric Acid Cycle (CAC) no longer function in the absence of oxygen? a. the CAC occurs after the ETC, so it can tell when O2 is not present b. the enzymes of the CAC can sense when O2 is present, and shut down when it is not there c. like many cofactors and coenzymes, O2 actually IS involved in the CAC, but we just don't show it in the reactions d. the cell doesn't need to make ATP when there is no O2, so the enzymes of the CAC are shut down e. all the electron carriers, including NADH, become fully reduced so oxidation of the molecules in the CAC can't occur they may be coupled with a spontaneous reaction in glycolysis: phosphate groups are attached to the 6-carbon glucose molecule for easier cleavage. This rxn in itself is not spontaneous, but when coupled w/ the e Answer- Which of the following is a CORRECT description of the role of enzymes in catalyzing biochemical reactions? a. Enzymes cut hard-to-break bonds, allowing the reaction to proceed. b. Enzymes provide the necessary activation energy to reach the transition state. c. Enzymes increase the ΔG of reactions, making them proceed rapidly. d. Enzymes decrease the ΔG of reactions, making them proceed rapidly. e. Enzymes stabilize the transition state and decrease its free energy. a Answer- Which of the following reactions is MOST likely to be exergonic? a. the digestion of protein from food into amino acids b. the formation of cellulose from individual glucose molecules c. the synthesis of a phospholipid from glycerol and fatty acids d. the replication of DNA from free nucleotides d Answer- Which one of the following statements about the formation of a peptide bond is INCORRECT? a. The reaction is endergonic. b. The reaction has a positive ΔG. c. None of the other answer options is correct. d. The reaction is spontaneous. e. The reaction is anabolic. a, b, c Answer- Which of the following describes ATP hydrolysis? (Select all that apply.) a. often coupled to a reaction that has a positive ΔG b. exergonic c. spontaneous a Answer- The energy of activation of a reaction is: a. the energy input needed to reach the transition state. b. the difference in energy between substrate and product. c. the difference in energy between the transition state and the product. d. equivalent to the ΔG of ATP hydrolysis. e. the net change in free energy. a Answer- Glycolysis, the breakdown of a glucose molecule to two molecules of pyruvate, is an example of a reaction that is: a. exergonic and catabolic. b. endergonic and anabolic. c. explosive. d. exergonic and anabolic. e. endergonic and catabolic. b Answer- In a reaction, enzymes change the: a. second law of thermodynamics. b. activation energy. c. first law of thermodynamics. d. ΔG. e. types of products e Answer- Enzymes are MOST often: a. triglycerides. b. sterols. c. nucleotides. d. carbohydrates. e. proteins. a, d Answer- Which of the following reactions would you predict could be coupled to ATP synthesis from ADP + Pi? (Select all that apply.) (+7.3 kcal/mol) a. creatine phosphate + H2O → creatine + Pi, ΔG - 10.3 kcal/mol b. glucose 6-phosphate + H2O → glucose + Pi, ΔG - 3.3 kcal/mol c. glutamic acid + NH3 → glutamine, ΔG + 3.4 kcal/mol d. glucose 1-phosphate + H2O → glucose + Pi, ΔG - 5.0 kcal/mol d. phosphoenolpyruvate + H2O → pyruvate + Pi, ΔG - 14.8 kcal/mol a Answer- The digestive tracts of cows and cats are structurally different. Cows have a "fermentation chamber" in their foregut that houses bacteria. Why might this anatomical structure benefit the cow? a. Cows are herbivores and do not produce cellulase. The chambers house bacteria that produce cellulase and make more of the nutrients in the cows' food available for absorption. b. Cows are larger than cats, therefore these chambers are necessary because of the size difference. c. Cows are herbivorous and the bacteria that live in the fermentation chambers increase the amount of nutrition that cows can absorb from the meat that they eat. d. Cows are herbivorous and need the fermentation chambers to acquire the extra energy from anaerobic respiration that is carried out there by the bacteria. c, d, e Answer- Which of the following statements about villi is/are CORRECT? (Select all that apply.) a. Villi secrete multiple types of digestive enzymes. b. Villi move food particles through the digestive tract. c. Villi serve to increase surface area. d. Villi allow for enhanced nutrient absorption. e. Villi can be found in both the jejunum and the ileum. a, b, d Answer- In humans, the stomach secretes: (Select all that apply.) a. hydrochloric acid. b. enzymes that digest lipids. c. amylase. d. pepsin, an enzyme that digests proteins. e. cellulase. c Answer- Aside from whatever digestion has happened before the food reaches the small intestine, the bulk of digestion takes place in the: a. appendix. b. colon. c. duodenum. d. ileum. e. jejunum. c Answer- To digest carbohydrates, digestive enzymes must first break them down into their subunits. To do this, the enzymes must catalyze the hydrolysis of: a. van der Waals forces. b. phosphodiester bonds. c. glycosidic bonds. d. peptide bonds. b Answer- The duct that connects the pancreas to the duodenum can sometimes become blocked. What is the result? a. The digestive enzymes are not affected because they are stored in the gallbladder until they are needed in the duodenum. b. The digestive enzymes back up into the pancreas and may start to digest the pancreas. c. The digestive enzymes produced by the pancreas still enter the duodenum because they travel by the blood to reach the duodenum, not by a duct. d. Nothing happens because the pancreas does not produce digestive enzymes. e. The digestive enzymes produced by the pancreas enter the large intestine instead and digestion proceeds as normal. e Answer- Because most herbivores do not produce cellulase, they have specialized compartments in their digestive tracts that: (Select all that apply.) a. provide appropriate temperature and pH for breaking down plant material. b. grind up the plant material using muscular gizzards or other structures. c. ferment nutrients in the hindgut. d. secrete alternative enzymes that carry out the same function as cellulase. e. house large populations of bacteria that do produce cellulase. c Answer- The pancreas secretes substances into ducts that connect to the _____ of the digestive system. a. stomach b. colon c Answer- Hormones are typically involved in maintaining _____, which is a given steady state for a particular factor (such as sugar or calcium levels in the blood). a. neural function b. physiology c. homeostasis d. cognitive ability d Answer- Imagine that a bowling ball is placed at various locations along a staircase. At which location does the ball possess the GREATEST amount of potential energy? a. The ball will have the same amount of potential energy no matter where it is placed. b. at the bottom of the stairs c. in the middle of the staircase d. at the top of the stairs c Answer- Weak covalent bonds, such as ones in carbohydrates and lipids, have: a. little potential energy. b. little kinetic energy. c. a lot of potential energy. d. a lot of kinetic energy. e. no potential or kinetic energy. T Answer- The energy of a system is defined as the system's capacity to do work. False True a Answer- Organic molecules store _____ energy in their _____ bonds. a. potential; covalent b. kinetic; covalent c. kinetic; hydrogen d. potential; ionic e. kinetic; ionic c Answer- The first law of thermodynamics is also known as the law of: a. conservation of mass. b. lost energy. c. conservation of energy. d. conservation of entropy. e. increased entropy. e Answer- Imagine that you are talking with one of your friends. He states that evolution has actually violated the second law of thermodynamics because complex living organisms are more ordered than the nucleic acids, amino acids, and other molecules that compose them. Why doesn't evolution contradict the second law of thermodynamics? a. Evolution actually does violate the second law of thermodynamics, and this fact is problematic for scientists. b. Evolution is a biological process, and biological processes do not have to conform to the laws of physics. c. Evolution doesn't affect entropy, as living organisms eventually die and become "disordered." d. Because evolution takes place over millions of years, the loss of entropy is negligible and thus the laws of thermodynamics are not violated. e. Even though evolution may decrease the entropy of living organisms, it increases the entropy of the Earth (or the universe) as organisms release heat. d Answer- Which of the following has the MOST entropy, individual nucleotides or a nucleic acid? a. The entropy of the nucleotides and nucleic acid would be the same. b. a nucleic acid c. It is impossible to determine the entropy of nucleotides or a nucleic acid. d. individual nucleotides a Answer- The second law of thermodynamics states that: a. there is an increase in disorder in the universe over time. b. combustion engines are 100% efficient. c. the universe becomes more orderly over time. d. only eukaryotic cells can produce ATP. e. energy cannot be created or destroyed. kinetic Answer- Energy of motion is ______ energy a Answer- Which of the following statements violates the first law of thermodynamics? a. Cells make energy when they produce ATP. b. The universe contains a constant amount of energy. c. Endergonic reactions store energy. d. The conversion of energy from one form to another is 100% efficient. potential Answer- Batteries in your flashlight are examples of ______ energy c Answer- The first law of thermodynamics states that: a. only eukaryotic cells can produce ATP. b. the universe becomes more orderly over time. c. energy cannot be created or destroyed. d. combustion engines are 100% efficient. e. there is an increase in disorder in the universe over time. a Answer- An example of potential energy is a ball sitting _____ of the stairs. a. All of these choices are correct. b. in the middle c. at the top d. at the bottom potential Answer- Stored energy is called _______ energy d Answer- Which of the following statements is NOT one of the laws of thermodynamics? a. The energy available to do work decreases as energy is transformed from one form to another. b. None of the other answer options is correct. c. The amount of energy in the universe is constant. d. All cells arise from pre-existing cells. c Answer- Which one of the following biological polymers is defined by a physical property instead of a chemical structure? a. nucleic acids b. polysaccharides c. lipids d. proteins e. monosaccharides c Answer- The association of individual water molecules with other water molecules is called _____ and occurs through _____ bonds between water molecules. a. cohesion; polar covalent b. adhesion; polar covalent c. cohesion; hydrogen d. adhesion; hydrogen e Answer- _____ are the subunits of nucleic acids, and _____ are the subunits of proteins. a. Nucleoli; amino acids b. Amino acids; nucleic bases c. Bases; polypeptides d. Polypeptides; sugars e. Nucleotides; amino acids b Answer- Carbohydrates and proteins are two types of macromolecules. Which functional characteristic of proteins distinguishes them from carbohydrates? a. tendency to make cell membranes hydrophobic b. ability to catalyze biochemical reactions c. None of the other answer options is correct.