Human Physiology Test Bank PDF

lOMoARcPSD|35516335 Exam Name___________________________________ Chapter 1 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Physiology is the study of...

lOMoARcPSD|35516335 Exam Name___________________________________ Chapter 1 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Physiology is the study of 1) A) the normal function of living organisms. B) the tissues and organs of the body at the microscopic level. C) growth and reproduction. D) the structure of the body. E) the facial features as an indication of personality. 2) The literal meaning of the term physiology is knowledge of 2) A) organs. B) math. C) science. D) chemistry. E) nature. 3) Because anatomy and physiology have different definitions, they are usually considered separately 3) in studies of the body. A) True B) False 4) The following is a list of several levels of organization that make up the human body. 4) 1. tissue 2. cell 3. organ 4. molecule 5. organism 6. organ system The correct order from the smallest to the largest is A) 4, 2, 3, 1, 6, 5. B) 4, 2, 1, 3, 6, 5. C) 6, 4, 5, 2, 3, 1. D) 2, 4, 1, 3, 6, 5. E) 4, 2, 1, 6, 3, 5. 5) "Glucose is transported from blood into cells because cells require glucose to meet their energy 5) needs." This type of explanation is A) teleological. B) scatological. C) mechanistic. D) theological. E) metalogical. 6) "Glucose is transported from blood into cells by transporters in response to insulin." This type of 6) explanation is A) scatological. B) mechanistic. C) metalogical. D) theological. E) teleological. 1  lOMoARcPSD|35516335 7) Which is a buffer zone between the outside world and most of the cells of the body? 7) A) red blood cells B) extracellular fluid C) cell membrane D) intracellular fluid E) All of the answers are correct. 8) Which is one of Cannon's "internal secretions"? 8) A) nutrients B) hormones C) water D) inorganic ions E) None of the answers are correct. 9) The study of body function in a disease state is 9) A) histology. B) necrology. C) microbiology. D) pathophysiology. E) physiology. 10) Homeostasis is the ability of the body to 10) A) prevent excessive blood loss. B) ignore external stimuli to remain in a state of rest. C) quickly restore changed conditions to normal. D) prevent the external environment from changing. E) prevent the internal environment from changing. 11) Oxytocin is a hormone released in response to cervical dilation. This causes more uterine 11) contractions that will further dilate the cervix. Which type of feedback does oxytocin trigger? A) positive feedback B) negative feedback C) local control D) nociceptive feedback 12) How genetics influences the body's response to drugs is called 12) A) pharmacodynamics. B) pharmacokinetics. C) pharmageddon. D) pharmacogenomics. E) paleopharmacology. 13) A physician basing clinical decisions on primary research published in biomedical literature is 13) doing ________ medicine. A) evidence-based B) traditional C) whimsical D) alternative E) holistic 14) A study in which a participant act as an experimental subject in part of the experiment and a 14) control in another part of the experiment is called a ________ study. A) crossover B) meta-analysis C) double-blind D) retrospective 2  lOMoARcPSD|35516335 15) The Internet database for molecular, cellular, and physiological information is called the ________ 15) Project. A) Physiome B) Manhattan C) Physiosome D) Human Genome E) Physiognomy 16) A placebo is 16) A) a nutritive and respiratory organ in fetal development. B) any drug being tested in a clinical trial. C) any drug in a class of drugs commonly used as pain relievers. D) a hole in a cavity wall through which an organ protrudes. E) a drug or treatment that is expected to have no pharmacological effect. 17) A technique used to resolve contradictory results in scientific studies is 17) A) longitudinal analysis. B) prospective analysis. C) retrospective analysis. D) cross-sectional analysis. E) meta-analysis. 18) A scientifically logical guess is a 18) A) theory. B) hypothesis. C) law. D) variable. E) model. 19) If a scientific model is supported or verified repeatedly by multiple investigators, it may become a 19) A) law. B) variable. C) model. D) theory. E) hypothesis. 20) Place these terms in the typical sequence in the process of scientific inquiry: experimental data, 20) theory, model, observation, hypothesis, replication. A) observation, replication, model, experimental data, hypothesis, theory B) experimental data, theory, model, observation, hypothesis, replication C) replication, hypothesis, experimental data, theory, model, observation D) theory, observation, experimental data, hypothesis, replication, model E) observation, hypothesis, experimental data, replication, model, theory 21) You are interested in learning more about Parkinson's disease, a neurological disorder that mainly 21) affects motor function. Which is the best source to begin your investigation? A) physiology textbook B) public library C) Ask.com D) a physician E) MedlinePlus 3  lOMoARcPSD|35516335 22) Which system(s) does NOT exchange material with the internal and external environments? 22) A) urinary system B) respiratory system C) circulatory system D) digestive system E) All of the above. 23) The human environment is terrestrial, dry, and highly variable. However, our bodies expend 23) enormous amounts of energy maintaining a constant internal environment. Studying why our bodies do this is what kind of approach? A) teleological B) mechanistic C) translational D) meterological E) anatomical 24) Individuals with Type I diabetes mellitus do not make enough insulin. Which would be a 24) mechanistic explanation of how insulin is used by the body? A) Insulin binds to its receptor which stimulates the movement of glucose transporters to the cell membrane. B) Since all cells need glucose, insulin is required. C) Insulin is a hormone involved in glucose transport. D) Without insulin most cells in the body would be unable to produce enough ATP. E) Cells need insulin because glucose will not cross the cell membrane. 25) Excretion is a function of the body. Which would be considered excretion? 25) A) Movement of salt from sweat glands to the surface of the skin. B) Movement of potassium from kidney cells into one's urine C) Movement of glucose from the kidney to the bloodstream. D) Movement of sodium from the intestines to the bloodstream. E) Movement of oxygen from the lungs to the blood stream. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 26) What is a nocebo effect? 27) List the key concepts or themes in physiology. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 28) Adaptive significance is an important concept in physiology because it describes the 28) A) parameters necessary to maintain a constant internal environment. B) importance of a highly variable external environment. C) similarities between ancient and modern marine organisms. D) ability of an organism to monitor and restore its internal state to normal conditions when necessary. E) physiological functions that promote an organism's survival. 4  lOMoARcPSD|35516335 29) You conduct an experiment on twenty 18-year-old male subjects to see how various intensities of 29) exercise affect heart rate. Which is/are an independent variable? A) age of subjects B) sex of subjects C) heart rate D) intensity of exercise E) More than one answer is correct. 30) You conduct an experiment on twenty 18-year-old male subjects to see how various intensities of 30) exercise influence heart rate. Which is/are a dependent variable? A) heart rate B) intensity of exercise C) sex of subjects D) age of subjects E) More than one of the answers is correct. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 31) Why are physiology and anatomy frequently studied together? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 32) You want to display data on the finish times of the 10 fastest race horses in a single race at the 32) Kentucky Derby. Which type of graph would be best to display this information? A) line graph B) bar graph C) scatter plot ESSAY. Write your answer in the space provided or on a separate sheet of paper. 33) You want to display data on the finish times of the 10 fastest race horses in a single race at the Kentucky Derby. What would the labels be for the graph axes? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 34) A horse runs 10 races, each a mile long, during a 6-month period, and you are interested in 34) determining if the horse's race finish time changes with experience. Which type of graph would be best to display this information? A) scatter plot B) bar graph C) line graph ESSAY. Write your answer in the space provided or on a separate sheet of paper. 35) A horse runs 10 races, each a mile long, during a 6-month period, and you are interested in determining if the horse's race finish time changes with experience. What would the labels be for the graph axes? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 36) There are 10 cloned horses, born on the same day, with identical chromosomes. They each follow 36) the same physical training regimen, but are given daily injections of different concentrations of a particular vitamin. They all run the same race. Which type of graph would be best to explore a relationship between race finish time and vitamin dose? A) scatter plot B) bar graph C) line graph 5  lOMoARcPSD|35516335 ESSAY. Write your answer in the space provided or on a separate sheet of paper. 37) There are 10 cloned horses, born on the same day, with identical chromosomes. They each follow the same physical training regimen, but are given daily injections of different concentrations of a particular vitamin. They all run the same race. What are the labels for the graph axes? 38) What is the difference between a peer-reviewed article and a review article? 39) What is an example of the deconstructionist view of biology? 40) Sahra has just flown around the world in the last 48 hours. She is having trouble sleeping, a condition known as insomnia. How do you think Sahra's long flights and her insomnia are related to biological rhythms? SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 41) Why do we need to label the axes of a graph? 41) MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 42) You go outside on a very cold day and you start to shiver because you do not have on the proper 42) clothing. The act of shivering would represent what step in a response loop? A) response B) integrating center C) variable D) sensor E) setpoint ESSAY. Write your answer in the space provided or on a separate sheet of paper. 43) Explain why the prefix homeo- is used in the term homeostasis. Why do some physiologists prefer the term homeodynamics over homeostasis? 44) Explain why animals are used in research. Are there any limitations to the application of animal data to human physiology? Could these limitations be addressed using cell or tissue culture, or computer simulations? 45) You conduct an experiment on twenty 18-year-old male subjects to see how various levels of exercise influence heart rate. Explain why only 18-year-old males were used as subjects. 46) Use these terms to develop a reflex loop: brain, sensory neuron, an eye, foot, soccer ball, motor neuron 47) Provide an example of a control system. Be sure to include the three main parts: an input signal, an integrating center, and an output signal. 48) Write a teleological explanation for why heart rate increases during exercise. Now write a mechanistic explanation for the same phenomenon. 6  lOMoARcPSD|35516335 SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 49) What is a hypothesis? What are the steps involved in following the scientific method? How 49) does one distinguish the dependent variable from the independent variable in an experiment? How are each of these represented on a graph? ESSAY. Write your answer in the space provided or on a separate sheet of paper. 50) You are designing a study to assess the effects of a new treatment for hypertension. What ethical considerations would you employ when monitoring your progress? 51) You are designing a study to assess the effects of a new drug treatment for hypertension. Your subjects are white males, ages 40 to 60 years. Can your study results be applied to all people? Explain. 52) High cholesterol levels have been shown to be a contribute to heart disease and death for many decades. In the 1970s, scientists used this information to develop a hypothesis that giving a medicine to reduce blood cholesterol levels could reduce the chances of developing cardiovascular disease or dying from cardiovascular disease. They tested a group of people living in Framingham, Massachusetts. This study became known as the Framingham Study, and it is very well known because it did not support the hypothesis. Does this mean that high cholesterol is not a risk factor for heart disease? What does this demonstrate about the scientific process, especially as it relates to human studies? You can find a copy of the study online and read it, if necessary. 7  lOMoARcPSD|35516335 Use the table and graph below to answer the following questions. Table 1.1 Figure 1.1 53) List all of the errors in Figure 1.1. 54) Why is a line graph to used to show the results of this study? 55) Use Table 1.1 to graph the data appropriately. What can you CONCLUDE based on the new figure? 8  lOMoARcPSD|35516335 Use the table and graph below to answer the following questions. Table 1.2 Figure 1.2 56) Summarize the data shown in Figure 1.2. 57) Referring to Table 1.2, what general trend in systolic blood pressures is seen as both males and females increase in age? 58) Referring to Figure 1.2, at approximately what ages do males have higher systolic blood pressures than females? At what age does this trend reverse? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 59) The human body is best described as always being in a state of equilibrium such that all body 59) compartments are identical. A) True B) False 9  lOMoARcPSD|35516335 ESSAY. Write your answer in the space provided or on a separate sheet of paper. Following is a table of data collected from one section of an 8 A.M. physiology lab. There were 20 students present, 10 males and 10 females. Information collected included students' height, weight, age, sex, and resting pulse rate. In addition, the students were surveyed to see if they smoked cigarettes, considered themselves "regular exercisers," and if they had consumed caffeine or eaten the morning of the lab. A "y" or "n" (yes or no) was recorded to indicate their answers. Each student did "jumping jacks" for 5 minutes and recorded the time required to return to their resting heart rate, which is list the table as "recovery time." Finally, each student's reaction time (in milliseconds) was measured by catching an object dropped partner according to specified criteria. Use this table to answer the following questions. Ignore statistical problems caused by small sample size, and so on. Table 1.3 Figure 1.3 For these questions, the data were separated and analyzed by gender. 10  lOMoARcPSD|35516335 60) Refer to Table 1.3 and Figure 1.3 A. Write a hypothesis regarding gender and weight. B. What is the dependent variable? What is the independent variable? C. Based on the data in the graph above, what is your conclusion? D. Why is a bar graph a good choice for presentation of these data? Would another type of chart be as effective? 61) Refer to Table 1.3. A. Write a hypothesis regarding sex and recovery time. B. What is the dependent variable? What is the independent variable? C. Create a graph using the averages from the data table. Based on these data, what do you conclude? 62) Refer to Table 1.3. A. Write a hypothesis regarding the effects of breakfast consumption on reaction time. B. What is the dependent variable? What is the independent variable? 63) Refer to Table 1.3. A. Ignoring the sex of the subjects, write a hypothesis that expresses the relationship between weight and height. B. What is the dependent variable? What is the independent variable? C. Construct a graph that examines relationship between weight and height. 64) Table 1.3 shows data on various factors that may or may not be related to resting pulse rate, time to recovery to resting pulse rate after a few minutes of exercise, and reaction time measured by how quickly a student could press a keyboard key after seeing a computer-generated prompt. For each question below, write a testable hypothesis, identify the dependent and independent variables, sketch an appropriate graph of the results, and dra conclusion from the data presented in the table. Discuss your results. A. Does caffeine consumption have an effect on resting pulse rate? B. Does age play a role in resting pulse rate? Does weight? C. Is there a relationship between eating breakfast and recovery time? D. Is there a relationship between reaction time and height? E. Do females who smoke show differences in their resting pulse rates compared to female nonsmokers or to mal smokers and male nonsmokers? F. Does regular exercise have an effect on resting pulse rate? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 65) The law of mass balance states 65) A) if one is to survive they must have a certain amount of mass. B) that all matter is neither created or destroyed. C) if a substance is to remain constant any gain must be offset by an equal loss. D) that homeostasis can be maintained when the load of a substance is continuously lost. E) that all substances in the body have equal mass. 66) Mass balance involves determining the total amount of a substance in the body. We can determine 66) mass flow of this substance by which formula? A) (concentration of a substance) × (volume/min) B) (concentration of a substance) / volume flow C) (amount of substance / min) × (concentration of the substance) D) intake + production - excretion - metabolism. E) volume of flow / (amount of substance / min) 11  lOMoARcPSD|35516335 67) ________ are kept within normal range by physiological control mechanisms which are used if the 67) variable strays too far from its ________. A) Independent variables, steady state B) Setpoints, regulated variable C) Steady state values, integrating center D) Dependent variables, lowest value E) Regulated variables, setpoint 68) Vasodilation of blood vessels supplying muscles in response to increased carbon dioxide during 68) exercise is an example of A) long-distance control. B) neural control. C) reflex control. D) hormonal control. E) local control. 69) Which are used to keep our systems at or near their setpoints? 69) A) open control loops B) response loops C) negative feedback loops D) positive feedback loops E) feedforward control loop 12  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED20 Chapter 1 1) A 2) E 3) B 4) B 5) A 6) B 7) B 8) B 9) D 10) C 11) A 12) D 13) A 14) A 15) A 16) E 17) E 18) B 19) D 20) E 21) E 22) C 23) A 24) A 25) A 26) It is the phenomenon whereby a patient who has been informed of the side effects of a drug he or she is taking is more likely to experience some of the side effects than an otherwise similar patient receiving the same drug who has not been so informed. 27) See Table 1.1 in the chapter. 28) E 29) D 30) A 31) This is discussed in the "Physiology Is an Integrative Science" section of the chapter. 32) B 33) The x-axis is horse name or number; the y-axis is finish time in minutes. 34) C 35) The x-axis is race number or date; the y-axis is finish time in minutes. 36) A 37) The x-axis is vitamin dose; the y-axis is finish time in minutes. 38) A peer-reviewed article describes original research by one author (or group of authors working together) that has gone through a screening process in which a panel of qualified scientists evaluate the work. A review article is a summary (usually a collection of published research that was previously peer-reviewed, usually from more than one independent lab) that discusses a particular topic in the field. 39) The deconstructionist view of biology predicted that once we uncovered the sequence of the human genome, the inner workings of the human body would be revealed. In reality, it is possible to know HOW a gene codes for a particular protein without knowing WHY that protein exists. Our knowledge of the human genome is only a piece of the puzzle. 40) Our sleep-wake cycle is a biological rhythm that lets our body know when it is time to rest. Most likely Sahra has ignored the signals like sleepiness, changes in body temperature, and mood that her body is sending. By ignoring these rhythms, she has disrupted the cycle and the body is struggling to maintain homeostasis. 13  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED20 41) A graph with no axis labels is meaningless–without knowing what trend is being illustrated, there is no communication of scientific information. 42) A 43) The prefix homeo-, meaning like or similar, is used to indicate that the body's internal environment is maintained within a range of acceptable values rather than a fixed state. Some physiologists argue that the term homeodynamics better reflects the small but constant changes that continuously take place in the internal environment, as opposed to homeostasis, which erroneously implies lack of change. 44) (Note to instructor: This may be a good question to ask early in the semester, then again toward the end, after the organ systems have been covered.) There is a brief discussion of using humans or animals in research in the chapter. This question is intended to stimulate students to think about how science is done, how data are generated, and how the process is challenged by social issues. Generally, there are limitations to the usefulness of computer simulations and cell/tissue culture systems for the same reason that nonhuman animal data are not 100% applicable to human physiology. How human organ systems perform may be different in very subtle ways from corresponding systems in other species. Cells in culture are in an artificial environment, and while much has been learned from such systems, it has also been noted that the behavior of cells in culture is not identical to cells in a living body. Furthermore, cells cultured from established lines can change over time, becoming less like the original cells from which they were derived, and presumably less like normal cells. Computer simulations are valuable, but are only as good as the data entered, and given that we don't know everything there is to know about physiology, we can't write a perfect computer program. All three approaches are useful, but for different reasons, and therefore one research system does not completely substitute for another, nor is it appropriate to abandon one entirely. 45) An important part of scientific inquiry is to remove sources of variation from among subjects. By choosing subjects of one gender in a particular age group, it is easier to determine that the dependent variable (heart rate, in this case) depends ONLY on the independent variable, level of exercise. This also allows a study to have fewer participants, assuming that subjects were randomly assigned to a level of exercise. If subjects were of random ages and genders, data would have to be collected from many more individuals. 46) Eye sees soccer ball. Sensory neuron sends visual information. Brain receives information and formulates a plan. Motor neuron sends action information from the brain. Foot and leg muscles contract, and the ball is kicked. 47) Variable. One example is blood glucose concentration. The input signal is a blood glucose concentration outside of the normal range, the controller is the pancreas, and the output signal is release of either insulin or glucagon. 48) Teleological: Heart rate increases because the increased activity of skeletal and cardiac muscles requires increased delivery of blood contents such as oxygen and glucose. Mechanistic: Heart rate increases in response to signals from the brain (pacemaker cells of the heart are stimulated by the nervous system). 49) This is discussed in "The Science of Physiology" section of the chapter and in Figure 1.15. 50) Major considerations should involve assessing the efficacy of the treatment such that the control group patients are not deprived as well as ensuring that the experimental treatment is not less effective than the standard treatments. 51) Possibly, but not necessarily. There are gender differences in appropriate therapies because of physiological effects of higher testosterone in males compared to females, for example. Drugs are often not tested in children, and children also have a different hormonal environment than adults (again, sex hormones are a good example, because their levels are low until just before the onset of puberty). There are also racial differences in effectiveness of therapies, and while it is a contentious issue as to whether these represent genetic or socioeconomic influences, they should be considered. 52) This demonstrates the difficulty in doing human research because, even though elevated cholesterol levels are a risk factor for cardiovascular disease, reducing cholesterol levels without addressing the reason those levels were high in the first place may not have the expected effect on reducing heart disease. Human testing on hypotheses is important because humans don't always respond to treatments like other animals do, they may actually respond quite differently and each person may respond differently from the rest. It is why we need to test each hypothesis in circumstances as similar to the actual real group that would be treated. 14  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED20 53) 1. The units of concentration are labeled as M when they should be mg. 2. The x-axis is in decreasing order of concentration. 3. The graph needs a legend. 54) Line graphs are commonly used when the independent variable (x-axis) is a continuous phenomenon. In this study the concentration of epinephrine is a continuous function. The line allows for interpolation (i.e., estimating values between the measured values). 55) Graphs should address the errors in Figure 1.1. This small sample suggests that an increase in epinephrine concentration increases the average heart rate of Sprague-Daw rats. 56) The systolic pressure of both genders increases with age. Under age 40, the systolic pressure of males is higher than that of females. After age 40, the systolic pressure of females is higher than that of males. The greatest rate of increase is from ages 50 to 70 in both genders. Blood pressure declines after age 70. 57) The systolic pressure of both genders increases until age 70 but declines after age 70. 58) From age 10 to 40, male pressures are higher; after age 40, female pressures are higher. 59) B 60) A. Males weigh more than females. B. Weight depends on gender; thus weight is dependent, gender is independent. C. Males weigh more than females. D. Bar graph allows comparison of the average of two groups. No. 61) A. A prediction such as "Males recover from exercise more quickly than females" would be appropriate. B. The independent variable is sex; the dependent variable is recovery time. C. A bar graph such as the one below is appropriate. In this study, males recovered from exercise more quickly than fem 62) A. A prediction such as "Eating breakfast prior to testing improves reaction time of subjects (compared to subjects who d eat breakfast)" is appropriate. B. The independent variable is breakfast consumption; the dependent variable is reaction time. 15  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED20 63) A. A prediction such as "As height increases, weight increases" would be appropriate. B. The dependent variable would be weight; the independent variable is height. C. 16  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED20 64) Answers will vary, but examples follow (conclusions written here are based on cursory examination of graphed data–no statistical tests of significance were performed). A. Hypothesis: Caffeine consumption increases heart rate. Independent variable: caffeine consumption. Dependent variable: resting pulse rate. Conclusion: Mean pulse rates between caffeine-drinking (68 bpm) and control subjects (73 bpm) are similar (large varia between individuals); hypothesis not supported. B. Hypothesis: Pulse rate is lower in older subjects and is higher in heavier subjects. Independent variables: age and weight. Dependent variables: resting pulse rate. Conclusion: Pulse rate was similar in all groups; hypothesis not supported. C. Hypothesis: Subjects who ate breakfast have a faster reaction time. Independent variable: breakfast consumption. Dependent variable: pulse rate. Conclusion: Subjects who ate breakfast had a faster reaction time (168.7 msec vs. 180.5 msec); hypothesis supported. D. Hypothesis: There is no relationship between height and reaction time. Independent variable: height. Dependent variable: reaction time. Conclusion: Reaction time did not vary with height; hypothesis supported. E. Hypothesis: Smokers of both sexes have a higher resting pulse rate than nonsmokers of either sex, and males and fem affected equally. Independent variables: smoking and sex. Dependent variable: pulse rate. Conclusion: There was no difference in pulse rate in any of the groups (70.4 bpm in nonsmokers vs. 70.3 bpm in smokers hypothesis not supported. F. Hypothesis: Subjects who exercise regularly have a lower resting pulse rate. Independent variable: exercise. Dependent variable: pulse rate. Conclusion: Regular exercise had no effect on resting pulse rate (68.9 bpm in nonexercisers vs. 71.8 bpm in exercisers); hypothesis not supported. Discussion may cover issues such as the effect of small sample size, use of adults of limited age range, lack of control over treatments (Were the subjects honest about age, eating breakfast, consuming caffeine, smoking, and exercising? Were the quantitative data of height and weight determined in the lab using the same equipment and same data collector?), the value of statistical analysis, and so on. It is likely that students will be surprised by some of the results and could make erroneous conclusions. For example, pulse rate may vary with age, but without including children and senior citizens in the sample population, this trend would be missed. 65) C 66) A 67) E 68) E 69) C 17  lOMoARcPSD|35516335 Exam Name___________________________________ Chapter 2 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) Stanley Miller set out to demonstrate an explanation for the origins of organic molecules using a 1) combination of simple organic molecules, heat and periodic bursts of electricity through the mixture, ultimately producing which kind of molecules? A) glycoproteins B) amino acids C) nucleic acids D) lipids E) carbohydrates 2) Glycosylated molecules are formed with 2) A) lysosomes. B) cholesterol. C) nucleic acids. D) carbohydrates. E) DNA. 3) Cells regulate their level of activity by regulating the amount of proteins in the cell at any given 3) time, so an up-regulation of enzymes would be expected to A) increase the cell's response produced by the reaction catalyzed by the enzyme. B) have no effect on the rate of reactions catalyzed by the enzyme. C) decrease the level of productivity of chemical reactions that rely on the enzyme. D) decrease the rate of reactions catalyzed by the enzyme. E) decrease the level of productivity of chemical reactions that rely on the enzyme and decrease the rate of reactions catalyzed by the enzyme. 4) When an enzyme reaches its saturation point, the amount of 4) A) substrate for the enzyme to act upon is very low and the amount of product produced by the enzyme decreases. B) product produced continues to increase. C) substrate for the enzyme to act upon is high. D) substrate for the enzyme to act upon is low. E) product produced by the enzyme decreases. 5) Which element make up more than 90% of the body's mass? 5) A) C, Na, K B) O, Ca, H C) O, H, Na D) Ca, C, O E) O, C, H 6) Phospholipids are key components of cell membranes and made up of which molecules? 6) A) nucleotides B) amino acids C) fatty acids D) glycerol and fatty acids E) glycerol 1  lOMoARcPSD|35516335 7) Chromium is 7) A) a dietary supplement with no natural role in the body. B) an essential element involved in glucose metabolism. C) a protein. D) not an element in the periodic table. 8) Which is a way to recognize a carbohydrate by looking at its name? 8) A) It begins with proteo-. B) It begins with lipo-. C) It ends in -ase. D) It begins with nucleo-. E) It ends in -ose. 9) Which is NOT an essential element for a living organism? 9) A) nitrogen B) mercury C) oxygen D) carbon E) hydrogen 10) The largest carbohydrate molecules are called polysaccharides because they are made up of 10) ________ molecules bonded together with one another. A) amino acid B) nucleotide C) pyrimidine D) purine E) simple sugar 11) Essential amino acids that are used to build proteins 11) A) exist in twenty six different forms. B) can only be made by cells within our bodies. C) must be derived from the foods we eat and digest. D) are linked together by ionic chemical bonds in proteins. E) can be used medically for both diagnosis and treatment of diseases. 12) Which is an example of a cation? 12) A) HCO3 - B) Ca2+ C) Cl- D) SO4 2- E) HPO4 2- 13) A positively-charged ion is called a(n) 13) A) proton. B) cation. C) electron. D) neutron. E) anion. 14) The most important polar molecule is ________ because it is a universal solvent in biological 14) solutions. A) magnesium sulfate B) water C) nucleic acid D) sodium chloride E) bicarbonate 2  lOMoARcPSD|35516335 15) A substance is highly soluble if it is 15) A) very likely to dissolve in water and is called aqueous. B) very likely to dissolve in water. C) not very likely to dissolve in water. D) not very likely to dissolve in water and is called aqueous. E) called aqueous. 16) A free radical is a 16) A) molecule with an extra proton. B) molecule with an extra neutron. C) molecule with an extra electron. D) charged particle. E) molecule with an unpaired electron. 17) The chemical bonding behavior of an atom is directly determined by the 17) A) number and arrangement of electrons. B) number of protons. C) number of neutrons. D) mass of the atom. E) size of the atom. 18) Atoms in a covalent molecule share electrons 18) A) in single pairs. B) in double pairs. C) singly, never in pairs. D) in triple pairs. E) can share electrons in single pairs, double pairs, or triple pairs. 19) The weak interactions between atoms that keep atoms near each other are called 19) A) van der Waals forces and ionic bonds. B) ionic bonds. C) hydrogen bonds. D) van der Waals forces. E) hydrogen bonds and van der Waals forces. 20) Which statement about carbohydrates is FALSE? 20) A) Simple sugars include galactose, glucose, and ribose. B) Glycogen is a storage polysaccharide made by animal cells. C) Polysaccharides include cellulose and glycogen. D) Polysaccharides are important both for energy storage and to provide structure to cells. E) Glycogen is important both for energy storage and to provide structure for cells. 21) In lipids, unsaturated refers to 21) A) the ring structure of steroids. B) fats, such as butter and lard, which come from animal sources. C) the presence of double bonds between adjacent carbon atoms in a fatty acid. D) glycerol, which acts as an anchor for joined fatty acids. E) the absence of double bonds between adjacent carbon atoms in a fatty acid. 3  lOMoARcPSD|35516335 22) Each amino acid differs from others in the 22) A) chemical structure of the R group. B) number of carboxyl groups. C) size of the amino group. D) number of central carbon atoms. E) number of peptide bonds in the molecule. 23) The alpha-helix and B-sheets are examples of the ________ structure of a protein. 23) A) primary B) secondary C) tertiary D) quaternary E) pentanary 24) Interactions between different globular or fibrous polypeptide chains result in which type of 24) structure? A) primary B) secondary C) tertiary D) quaternary E) pentagonal 25) The concentration of a solution expresses the amount of 25) A) solute per volume of solvent. B) solvent per volume of solution. C) solute per volume of solution. D) solvent per volume of solute. E) None of the answers are correct. 26) Nucleic acids are polymers of units called 26) A) amino acids. B) bases. C) ribose. D) fatty acids. E) nucleotides. 27) A nucleotide is made up of a 27) A) five-carbon sugar and an amino acid. B) five-carbon sugar and phosphate group. C) five-carbon sugar and a nitrogenous base. D) phosphate group and a nitrogenous base. E) five-carbon sugar, a nitrogenous base, and a phosphate group. 28) A nucleotide containing the base cytosine would base pairs with a nucleotide containing the base 28) A) cytosine. B) uracil. C) thymine. D) guanine. E) adenine. 4  lOMoARcPSD|35516335 29) An energy-transferring compound in cells is a nucleotide known as 29) A) glucose. B) deoxyribonucleic acid. C) fructose. D) adenosine triphosphate. E) protein. 30) Which bases are purines? 30) 1. adenine 2. cytosine 3. guanine 4. thymine 5. uracil A) 1 and 2 B) 1, 3, and 5 C) 2 and 3 D) 1 and 3 E) 2, 4, and 5 31) Biomolecule polymers are a typical formation of ________ molecules. 31) A) inorganic B) organic C) either organic or inorganic 32) Cholesterol is a 32) A) component of animal cell membranes. B) precursor to steroid hormones. C) dangerous fat that is absent from a healthy body. D) A and B E) A, B, and C 33) An important buffer in the human body is 33) A) NaCl. B) H+. C) HCl. D) H2 O. E) HCO3 -. 34) Which of the following is most alkaline? 34) A) tomato juice, pH = 4 B) urine, pH = 6 C) lemon juice, pH = 2 D) stomach secretions, pH = 1 E) white wine, pH = 3 35) If a solution has a pH that is less than 7, it is 35) A) a salt. B) a buffer. C) alkaline. D) acidic. E) neutral. 36) Protein specificity is the 36) A) degree to which a protein-ligand complex initiates a response. B) activation of a specific protein that is needed to perform a particular function. C) degree to which a protein is attracted to a ligand. D) ability of a protein to bind a certain ligand or a group of related ligands. E) B and C 5  lOMoARcPSD|35516335 37) Which is a common feature of soluble proteins? 37) A) chemical modulation B) receptor binding C) structural support D) noncovalent interaction E) All of the answers are correct. 38) An ion has gained or lost 38) A) proton(s). B) neutron(s). C) electron(s). D) carbon atom(s). E) double bond(s). 39) An isotope has gained or lose 39) A) proton(s). B) neutron(s). C) electron(s). D) carbon atom(s). E) double bond(s). 40) The number of ________ determines the element. 40) A) protons B) neutrons C) electrons D) carbon atoms E) double bonds 41) This subatomic particle has a positive charge. 41) A) electron B) sodium chloride C) proton D) neutron E) molecular oxygen 42) This subatomic particle has a negative charge. 42) A) hydrogen B) electron C) magnesium D) proton E) neutron 43) This subatomic particle has a neutral charge. 43) A) electron B) proton C) neutron D) magnesium E) hydrogen 6  lOMoARcPSD|35516335 44) A change in pH value of one unit indicates a 44) A) 1-fold change in [H+ ]. B) change of 10-2 in pH. C) 10 fold change in [H+ ]. D) change of 10-1 in pH. E) Cannot be determined. 45) A blood pH of less than 7.00 and greater than 7.70 is incompatible with life. 45) A) True B) False 46) Which statement describes the relationship between pH and hydrogen ions? 46) A) pH and hydrogen ions are inversely related. B) pH and hydrogen ions are independent and unrelated. C) pH and hydrogen ions are equivalent. D) pH is always 100 times more than the number of hydrogen ions. E) pH and hydrogen ions are directly related. 47) HCl (hydrochloric acid) is an acid because 47) A) in solution it donates its H+. B) in solution it increases the pH. C) it is able to form hydroxide ions. D) in solution it decreases the concentration of free H+. E) it is similar to ammonia. 48) Molecular structure and function of large complex biomolecules result from which interactions? 48) A) ionic bonds B) hydrogen bonds C) van der Waals forces D) covalent bond angles E) All of the choices can contribute. 49) Which formula describes the relationship between pH and hydrogen ions? 49) A) pH = log [H+ ] B) pH= [H+ ] + [OH-] C) [H+] = -log pH D) pH = -log [H+ ] E) [H+] = log pH 50) All organic molecules contain 50) A) adenosine. B) lipids. C) carbon. D) oxygen. E) calcium. 51) Molecules that contain carbon are known as 51) A) atoms. B) nonessential elements. C) minerals. D) protons. E) organic molecules. 7  lOMoARcPSD|35516335 52) Which elements make up 90% of the body's mass? 52) A) carbon dioxide, oxygen, and sodium B) oxygen, carbon, and nucleic acids C) sodium, potassium, and calcium D) hydrogen, nitrogen, and oxygen E) oxygen, carbon, and hydrogen 53) Which results when an atom has such a strong attraction for electrons that it pulls one or more 53) electrons completely away from another atom? A) ionic bond B) Van der Waals attraction C) covalent bond D) weak bond E) hydrogen bond 54) These are weak attractive forces that are responsible for the surface tension of water. 54) A) Van der Waals attractions B) covalent bonds C) ionic bonds D) hydrogen bonds E) potassium bonds 55) These result when the carbon atoms in phospholipids share a pair of electrons. 55) A) potassium bonds B) ionic bonds C) covalent bonds D) Van der Waals attractions E) hydrogen bonds 56) Van der Waals forces are weak attractive forces between the nucleus of one atom and the electrons 56) of another atom close by. A) True B) False 57) Glycogen is an example of a 57) A) nucleotide. B) carbohydrate. C) lipid and protein. D) protein. E) lipid. 58) Nucleotides perform which function(s)? 58) A) They are the building blocks of proteins like cell receptors. B) They transfer energy and are part of genetic material. C) They store glucose as fat. D) They are the starting material for steroid hormones. E) They form structural elements in the cell membrane. 8  lOMoARcPSD|35516335 59) Which biological molecules exhibit saturation, specificity and competition? 59) A) lipids B) proteins C) lipids and proteins D) nucleotides E) carbohydrates 60) Triglycerides and steroids are examples of 60) A) carbohydrates. B) proteins. C) nucleotides. D) lipids. E) lipids and proteins. 61) Potassium channels are usually made up of several subunits. This is an example of which level of 61) protein structure? A) primary B) secondary C) tertiary D) quaternary E) alpha helix 62) The sequence of amino acids in the chain is an example of which level of protein structure? 62) A) primary B) secondary C) tertiary D) quaternary E) alpha helix 63) Hemoglobin molecules are made from four globular protein subunits. The three-dimensional 63) shape of these globular subunits is an example of which level of protein structure? A) primary B) secondary C) tertiary D) quaternary E) alpha helix 64) β-strands are an example of a flat arrow arrangement of amino acids. 64) A) True B) False 65) Which level of protein structure occurs from spontaneous folding that results from covalent bonds 65) and noncovalent interactions? A) triangular B) tertiary C) primary D) quaternary E) secondary 9  lOMoARcPSD|35516335 66) The protein keratin which is found in hair and nails is categorized as which protein shape? 66) A) globular B) acidic C) triangular D) fibrous E) hexavalent 67) Which types of bonds between amino acids plays an important role in the shape of globular 67) proteins? A) collagen bonds B) disulfide bonds C) metallic bonds D) sodium bonds E) secondary bonds 68) Which would be disrupted by changes in free hydrogen ions in solution, thus disrupting the 68) molecule's shape and function? A) double bonds B) sodium bonds C) hydrogen bonds D) covalent bonds E) disulfide bonds 69) During intense exercise our muscles produce lactate and hydrogen ions. Which molecules would 69) be affected by the accumulation of hydrogen ions? A) DNA in the nucleus B) phospholipids in the membrane C) glucose molecules in the adipose tissue D) the proteins actin and myosin E) cholesterol in the plasma membrane 70) Which best describes an irreversible antagonist? 70) A) binds to proteins away from the active site B) reversible agonist C) involved in activation via phosphorylation D) allosteric enhancer E) cannot be displaced by competition 71) Protein kinase A is a molecule inside our cells that can activate enzymes within the cell. Protein 71) kinase A does this by adding phosphates to the enzymes. This is which type of modulation? A) competitive inhibitor B) allosteric modulator C) reversible antagonist D) covalent modulator E) irreversible agonist 10  lOMoARcPSD|35516335 72) A reaction is stopped by substance X but can recover when more of the customary ligand is 72) supplied. Substance X is an example of a A) competitive inhibitor. B) phosphatase. C) covalent modulator. D) irreversible antagonist. E) allosteric modulator. 73) Which is an allosteric modulator? 73) A) A substance that binds irreversibly. B) A substance involved in activation via phosphorylation. C) A substance that can be displaced by competition at the active site. D) A substance that has no effect on the affinity of the ligand. E) A substance that binds to proteins away from the active site. 74) The smallest organizational level is a(n) 74) A) tissue. B) element. C) molecule. D) nucleus. E) atom. 75) When two or more atoms are chemically linked, they form a(n) 75) A) nucleus. B) molecule. C) atom. D) tissue. E) element. 76) Oxygen, carbon, and hydrogen, along with eight other elements are considered 76) A) compounds. B) molecules. C) major essential elements. D) minor essential elements. E) atoms. 77) The center of an atom is called the 77) A) molecule. B) electron. C) element. D) nucleus. E) proton. 78) Electrons travel around the center of the atom at high speed forming a(n) 78) A) nucleus. B) shell. C) atom. D) element. E) molecule. 79) An element's ability to bind other elements is determined by 79) A) the arrangement of electrons in the outer shell of an atom. B) the amount of folding in its subunits. C) its state of glycosylation. D) its amino acid composition. E) the number of enzymes required. 80) Ions with a positive charge are called 80) A) electrons. B) cations. C) tissues. D) anions. E) neurons. 81) Ions with a negative charge are called 81) A) anions. B) electrons. C) neurons. D) tissues. E) cations. 11  lOMoARcPSD|35516335 82) A ________ is a made up of solutes dissolved in a solvent. 82) A) nucleus B) molecule C) cocktail D) compound E) solution 83) Substances that easily dissolve in water are 83) A) lipids. B) isotonic. C) nonpolar. D) hydrophobic. E) hydrophilic. 84) Substances that do not dissolve well in water are 84) A) hydrophilic. B) isotonic. C) polar. D) hydrophobic. E) salts. 85) A(n) ________ is any molecule or ion that binds to a receptor protein. 85) A) ligand B) vitamin C) enzyme D) cofactor E) phospholipid 86) Two methods of protein activation include ________ and ________. 86) A) homeostatic, osmotic B) proteolytic, cofactor binding C) mechanistic, covalent bonding D) exergonic, endogonic E) enzymatic, glycolytic 87) DNA contains the five-carbon sugar 87) A) lactose. B) deoxyribose. C) uracil. D) glucose. E) ribose. 88) RNA contains the five-carbon sugar 88) A) glucose. B) uracil. C) deoxyribose. D) ribose. E) lactose. 12  lOMoARcPSD|35516335 89) The purines found in DNA are ________ and ________. 89) A) cytosine, thymine B) cytosine, uracil C) deoxyribose, guanine D) guanine, cytosine E) adenine, guanine 90) The pyrimidines found in DNA are ________ and ________. 90) A) guanine, cytosine B) deoxyribose, guanine C) adenine, guanine D) cytosine, uracil E) cytosine, thymine 91) In a chemical reaction, ________ between atoms are broken as atoms are rearranged in new 91) combinations to form different chemical substances. A) chemical bonds B) electron shells C) homeostatic interactions D) protons E) nuclei 92) The reaction rate of many chemical reactions that occur in the body are controlled by molecules 92) called A) nucleic acids. B) enzymes. C) purines. D) neurotransmitters. E) intermediates. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 93) How many milliequivalents are represented by a mole of bicarbonate ions (HCO3 - )? 94) List and define the seven categories of soluble proteins. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 95) Which elements combine to form nonpolar covalent bonds? 95) A) carbon and hydrogen B) carbon and chlorine C) hydrogen and oxygen D) sodium and chlorine E) nitrogen and hydrogen 96) The symbol Ca2+ means calcium has 96) A) lost two protons. B) gained two protons. C) lost two electrons. D) gained two electrons. 13  lOMoARcPSD|35516335 97) In a 5% NaCl solution, 97) A) there are 5 grams of sodium chloride for every 100 mL of water. B) the solute is water. C) there are 5 grams of sodium chloride for every 100 mL of total solution. D) A and B E) A and C SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 98) A molecule of sucrose has a molecular weight of 342 Daltons. How many grams of sucrose 98) would be required to make one liter of a 2.5 Molar solution of sucrose? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 99) A covalent double bond is formed when atoms 99) A) swap two pairs of electrons. B) transfer a pair of electrons from one atom to the other. C) transfer two pairs of electrons from one atom to the other. D) share one pair of electrons (a total of two). E) share two pairs of electrons (a total of four). 100) The term polar is used to describe molecules because 100) A) there are at least two distinct ends of the molecule regarding electron position and the resulting charge. B) polar covalent molecules were first discovered in polar bears. C) such molecules are always linear in shape. D) there are at least two distinct ends of the molecule regarding hydrogen placement. E) polar covalent molecules are found in colder climates. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 101) The more likely a fat is to be solid at room temperature, the more it potentially can contribute to cardiovascular disease. With this in mind, which fats will be the most dangerous? MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 102) Lipids are hydrophobic, and do not usually dissolve in water. Because blood is water-based, the 102) lipid cholesterol is combined with ________ so it can be transported by blood. A) cations B) hydrophilic molecules C) anions D) nothing; cholesterol is not transported in blood E) hydrophobic molecules 103) Only free H+ contributes to the hydrogen ion concentration. 103) A) True B) False 104) In the equation CO2 + H2 O ↔ H2 CO3 ↔ H+ + HCO3 - , which of these is an acid? 104) A) CO2 B) HCO3 - C) H2 CO3 D) H2 O E) H+ 14  lOMoARcPSD|35516335 105) Chemical reactions that occur in the human body proceed at a faster rate due to special catalytic 105) molecules called A) enzymes. B) cytozymes. C) proteins. D) antagonists. E) antibodies. 106) The fuel molecule cells use to run all their activities is 106) A) vitamins. B) glucose. C) sucrose. D) starch. E) protein. 107) A fatty acid that contains three double bonds in its carbon chain is said to be 107) A) carboxylated. B) saturated. C) monounsaturated. D) hydrogenated. E) polyunsaturated. 108) Most of the lipid found in the human body is in the form of 108) A) monoglycerides. B) phospholipids. C) steroids. D) prostaglandins. E) triglycerides. 109) Each of the following is a function of proteins EXCEPT 109) A) signaling. B) catalyst. C) transport. D) storage of genetic information. E) binding to ligands. 110) If a polypeptide contains 10 peptide bonds, how many amino acids does it contain? 110) A) 11 B) 10 C) 0 D) 5 E) 12 111) Glycoprotein molecules 111) A) allow atoms to pack closely together and occupy minimum space. B) increase the solubility of lipids. C) act as buffers in body fluids. D) aid in the formation of chemical bonds between carbon atoms. E) create a coat on the cell surface that assists in cell aggregation and adhesion. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 112) Compare and contrast the role of up-regulation and down-regulation of proteins. 113) What is the induced-fit model? List the types of bonds involved and classify them as strong or weak. 15  lOMoARcPSD|35516335 SHORT ANSWER. Write the word or phrase that best completes each statement or answers the question. 114) The ________ of a solution is the negative logarithm of the hydrogen ion concentration, 114) expressed in moles per liter of solution. 115) When a nitrogenous base is bonded to a pentose sugar and a phosphate, a ________ is 115) formed. 116) Solutions are formed with water and ________ solutes which dissolve in them. 116) 117) The ________ molecules which form the bilayer region of the cell membrane have 117) hydrophilic regions on the outer surface and hydrophobic regions on the inner surface. ESSAY. Write your answer in the space provided or on a separate sheet of paper. 118) Compare and contrast the chemical bonds between adjacent monomers in DNA, and between two strands of DNA. 119) Compare and contrast the general chemical structures of monosaccharides and amino acids. 120) What are functional groups? List the common functional groups in biological molecules. 121) True or False? Lipids are hydrophobic because they easily dissolve in water. If true what allows them to dissolve in water or if false, what is it about their molecular structure that makes them less likely to dissolve in water? 122) Explain the polar character of an ammonia molecule (NH3 ). What is the cause of the partial charges? What is the overall charge for NH3? 123) Water striders are insects that literally walk on water. These insects are frequently found living on ponds. If hydrogen bonds did not exist, how would this affect the life of water striders? 124) If the dissociation constant of a protein is less than one (Kd < 1), what can you conclude about the affinity of the protein for the ligand? 125) Noncovalent molecular interactions occur between many different biomolecules and often involve proteins. Give an example of such an interaction and what the function might be. 126) Tenzin is assigned a project regarding ions, isotopes, and free radicals. Her teacher tells her that she has to describe what is similar between them, and how they are different. Tenzin is having some trouble, and calls you in for help. Assuming she has learned and understood some basic chemistry, help her organize her thoughts by making a table or flow chart. 127) Ahmed is trying to memorize chemical structures of every compound his professor has indicated are important to the human body. Explain to him that an easier way is to memorize a few rules of chemical bonding and then figure out the structure of the important compounds, especially the simpler compounds. 128) Define polar covalent, nonpolar covalent, ionic, and hydrogen bonding. Which of these bonds involves more than one molecule? Which of these bonds is/are important in determining the properties of water? Explain. 16  lOMoARcPSD|35516335 129) Ionic bonds are considered to be strong chemical bonds. Yet, ions dissociate in water. Explain how both can be true. 130) Your swimming buddy, Mario, jumped into a pool parallel to the water surface. When he stood up, he yelled "ouch," and you noticed that the skin on his chest and belly looked red and irritated. How would you describe the properties of water to explain to Mario why this happened? Why doesn't it hurt when pool water is penetrated perpendicular to the surface, as with a hands-first or feet-first dive? 131) You are helping your dad prepare food in the kitchen. Dad has a tablespoon of water in one hand and a tablespoon of vegetable oil in the other, when he trips over the rug and spills both spoons on the countertop. Dad notices that the oil forms a thin film on the countertop, whereas spilled water forms smaller, taller beads. How should you explain the different behavior of these liquids to your dad? 132) Mahamoud is confused on the similarities and differences between proteins and nucleic acids. Assuming he has learned and understood the basic chemistry, what is the likely source of his confusion? To help him sort this out, make a table or flow chart to explain the structure of these molecules and their relationship to each other. 133) Proteins are described as having different levels of structure. List and distinguish between the level(s) that produce a linear shape vs. a globular shape, and explain why one of those levels can result in either a linear or globular shape. 134) While every level of a protein's structure is important to the function of that protein, which level of structure is most important to the function of enzymes, and why? 135) You are a student intern in the research and development department of a pharmaceutical company. You have discovered a compound that destroys the common cold virus in cultured human cells. Chemical characterization reveals that carbon, hydrogen, and oxygen are present, in a 20:40:4 ratio of C:H:O. Experiments in rats show that neither oral nor injectable treatment with the compound was effective in destroying the virus. Discuss some possible reasons for this lack of effectiveness. 136) Describe what happens to NaCl when placed in water. MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 137) How many grams of glucose, molecular mass = 180 Daltons, is necessary to make 1 liter of a 1.0 137) molar solution? A) 180 B) 1.0 C) 90 D) 360 E) 6.02 × 1023 138) A 5 M solution of 100 mL of glucose contains how many grams of glucose, molecular mass = 180 138) Daltons? A) 90 B) 6.02 × 1023 C) 180 D) 1.0 E) 360 17  lOMoARcPSD|35516335 139) If 100 mL of water contains 5 grams of NaCl, molecular mass = 58.5 Daltons, what is the molarity of 139) the solution in moles/L? A) 0.085 B) 0.25 C) 0.85 D) 2.92 E) 0.05 140) How many grams of NaCl, molecular mass = 58.5 Daltons, are the molar equivalent to 90 g of 140) glucose (molecular mass = 180 daltons)? A) 0.5 B) 14.6 C) 117 D) 0.25 E) 29.25 141) How many grams of NaCl, molecular mass = 58.5 Daltons, are necessary to make 1 liter of 5% 141) saline? A) 58.5 B) 6.02 × 1023 C) 50 D) 1 E) 2.9 142) A typical blood concentration of glucose is 100 mg/dL. The molecular weight of glucose is 142) approximately 180 Daltons. What is the molarity of this solution in millimoles? A) 100 B) 0.56 C) 5.6 D) 10 E) 18 143) If in an acid-base reaction H2 SO4 2- donates two H+ , one mole of H2SO42- would equal how 143) many equivalents? A) 2 B) 1 C) 0.75 D) 0.5 E) 4 ESSAY. Write your answer in the space provided or on a separate sheet of paper. 144) What is the difference between atomic mass and molecular mass. 145) A. Distinguish between the mass of a molecule and the mass of a mole, using NaCl in your example. B. Calculate the mass of a mole of NaCl in g, using the mass of one Da (amu). C. Calculate the mass of a dozen NaCl molecules, a dozen donuts, and a mole of donuts, assuming a 30 gram don 146) Write the chemical formula for the molecule drawn below. Which class of organic molecule does it belong to? Is i likely polar or nonpolar? 147) What is the pH of a 0.005 M HCl solution? Assume complete dissociation. 18  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED21 1) B 2) D 3) A 4) C 5) E 6) D 7) B 8) E 9) B 10) E 11) C 12) B 13) B 14) B 15) B 16) E 17) A 18) E 19) E 20) E 21) C 22) A 23) B 24) D 25) C 26) E 27) E 28) D 29) D 30) D 31) B 32) D 33) E 34) B 35) D 36) D 37) D 38) C 39) B 40) A 41) C 42) B 43) C 44) C 45) A 46) A 47) A 48) E 49) D 50) C 19  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED21 51) E 52) E 53) A 54) D 55) C 56) A 57) B 58) B 59) B 60) D 61) D 62) A 63) C 64) A 65) B 66) D 67) B 68) C 69) D 70) E 71) D 72) A 73) E 74) E 75) B 76) C 77) D 78) B 79) A 80) B 81) A 82) E 83) E 84) D 85) A 86) B 87) B 88) D 89) E 90) E 91) A 92) B 93) 1000 milliequivalents. This is calculated by taking the equivalent value of the molecule, which equals the molarity of the molecule (1 in this case) times the number of charges the molecule carries (in this case, the minus symbol indicates a charge of negative one, i.e., -1), so 1 × 1 = 1 equivalent. 1 equivalent = 1000 milliequivalents. 94) The seven categories: enzymes, membrane transporters, signal molecules, receptors, binding proteins, regulatory proteins, and immunoglobulins. See the "Protein Interactions" section of the chapter. 95) A 96) C 97) C 20  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED21 98) 805 grams (per liter). This is calculated by multiplying the amount of sucrose in one liter of a 1 molar solution (342 grams) times the molar concentration (2.5). 342 × 2.5 = 805 grams 99) E 100) A 101) The more saturated or the higher the number of hydrogens a fat contains, the more likely it will be solid at room temperature. Therefore, saturated animal fats are the most associated with cardiovascular disease. 102) B 103) A 104) C 105) A 106) B 107) E 108) E 109) D 110) A 111) E 112) These terms refer to the net change in the amount of a functional protein present in a cell in response to a signal. Up-regulation is an increase in the amount of the protein, whereas down-regulation is a decrease. 113) The interaction between a protein binding site and a ligand that are in close proximity results in a conformational change of the protein to fit more closely to the ligand. The bonds involved are hydrogen (weak), ionic (strong), and van der Waals (weak). 114) pH 115) nucleotide 116) hydrophilic 117) phospholipid 118) The bonds holding monomers together are covalent bonds, between sugar and phosphate molecules. The bonds holding neighboring strands together at the complementary bases are hydrogen bonds. 119) Monosaccharides consist of carbon, hydrogen, and oxygen, in the ratio C:H:O of 1:2:1. Amino acids consist of a central carbon (CH), a carboxylic acid (COOH), an amine (NH2 ), and an organic side chain of variable structure (mainly a hydrocarbon chain, designated as R). 120) Several combinations of atoms that occur repeatedly in biological molecules. See Table 2.1 in the main text. 121) False. Lipids are considered hydrophobic because they have an even distribution of electrons and no positive or negative poles. Thus, nonpolar molecules have no regions of partial charge, and therefore tend to repel water molecules. 122) When chemically bonded with each other, the nitrogen atom is partially negative whereas the hydrogen atoms are partially positive. The nitrogen atom in a molecule of ammonia has a stronger attraction for the electrons participating in the covalent bonds than the hydrogen atoms. The net charge on the molecule is still zero, however. 123) Hydrogen bonds are responsible for the surface tension of water, the attractive force between water molecules that can make it difficult to separate them. The surface tension is strong enough to support the weight of water striders, thus allowing them to walk on water. If water molecules could not form hydrogen bonds, the water striders would not be able to walk on water because there would be no surface tension to support their weight. Therefore, these insects would have to adapt to terrestrial conditions near ponds or lakes rather than living on them. 124) Since Kd < 1, you know that [P][L] < [PL]. Therefore, at equilibrium, there is a higher concentration of protein-ligand complex suggesting that the protein has a relatively high binding affinity for the ligand. 125) Examples of such interactions would be the interactions between carbohydrates, proteins, and lipids. These interactions form molecules like glycolipids and glycoproteins. These molecules are usually used as signaling molecules on the surfaces of cells. 21  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED21 126) All of these terms are similar in that they describe a structure that has either gained or lost something but different in their overall function. An ion is an atom that has gained or lost one or more electrons and thus bears an electrical charge. Ions form when salts dissolve in water and are required for normal cell function. An ion's charge affects both its behavior in solution and its chemical reactivity. An isotope is an atom that has gained or lost one or more neutrons; as neutrons lack a charge, isotopes remain neutral. Some isotopes emit radiation, a type of energy, rendering them both useful and dangerous; compared to ions, they are rare in nature. A free radical is an atom or molecule that has at least one unpaired electron (an electron is more stable if paired with another electron). Free radicals can be either electrically charged (e.g., superoxide) or neutral (e.g., hydroxy), depending upon the total number of protons and electrons present. Because free radicals are unstable, they are highly reactive and disruptive to cell function; compared to ions, they are rare in the body. Neither isotopes nor free radicals are known to be required for normal cell function. 127) Elements combine to form molecules in predictable ways because of how the outer shell electrons combine between atoms. In most cases, the outer shell will be most stable with a total of eight electrons. This information is easily discernible from the periodic table. Therefore an atom with seven outer shell electrons, such as K, combines very readily with an atom with one outer shell electron, such as Cl; an atom with six outer shell electrons, such as Ca will combine with an atom with two outer shell electrons or with two atoms with one outer shell electron each, and so on. Examples: KCl, CaCl2 , CH4. 128) Polar covalent bonds occur within a single molecule that shares electrons unequally; i.e., the constantly orbiting electrons spend more time at some locations and less at others. Nonpolar covalent bonds occur within a single molecule that shares electrons equally; i.e., the probability of an electron occupying a particular location is the same at all locations. Ionic bonds occur within a single molecule in which one atom completely loses an electron to another, causing each to develop an opposite charge; it is this electrical attraction that holds the molecule together. Hydrogen bonding occurs between separate molecules that contain polar covalent bonds; where electrons spend more time the molecule is partially negative, and where electrons spend less time the molecule is partially positive. The ends of different molecules are thus electrically attracted to each other. Water is a polar covalent molecule, with the oxygen end being partially negative and attracted to the partially positive hydrogen portions of other water molecules. Hydrogen-bonding between water molecules is responsible for surface tension and the crystalline structure of ice. 129) Molecules such as sodium chloride are bonded by ionic bonds. So much energy would be required to separate a molecule of NaCl into Na + and Cl- that it is practically impossible. That is, if the sodium chloride is DRY. Because water molecules have partial charges resulting from their polar covalent bonds, sodium chloride dissociates in water. This means that the ions separate and function relatively independently. An attraction between sodium and chloride still exists, however, and the dissociation can be described as an increase in bond length rather than a loss of the bond. Evaporate the water, though, and the sodium chloride crystals reform. 130) Because Mario was parallel to the water surface, the force of his mass was spread out over a relatively large area of the water, making the force per unit water lower than in a typical dive. The surface tension of water, while not strong enough to keep Mario from penetrating the water surface, was strong enough to momentarily resist him. The force of the water pushing back on Mario, however briefly, was enough to cause pain. In a typical dive position, the force of Mario's entire mass is spread only over a tiny area of the water, and thus the force per unit water surface is greater. This higher force is sufficient to immediately break the hydrogen bonds and overcome the surface tension. 131) Water forms beads when it strikes a nonabsorptive surface because of surface tension resulting from the hydrogen bonds between neighboring water molecules. Vegetable oil molecules are nonpolar covalent, therefore, there is no hydrogen bonding between the lipid molecules and no bead formation. 132) His confusion probably stems from the fact that both proteins and nucleic acids are classified as macromolecules, and both are assembled by covalently bonding certain monomers in a particular order. Also, nucleic acids contain the information necessary for manufacturing proteins, the term acid is used in describing the structure of both nucleic acids and proteins, and both nucleic acids and proteins must contain nitrogen. The monomer of protein is the amino acid, which has a central carbon, a variable chain denoted as R, and a nitrogen-containing amino group. There are 20 naturally occurring amino acids. The monomer of the nucleic acid is the nucleotide, which has a sugar attached to a nitrogen-containing base, and a phosphate. There are five different bases and two different sugars. The sequence of bases in a DNA or RNA molecule determines the sequence of amino acids in the protein. 22  lOMoARcPSD|35516335 Answer Key Testname: UNTITLED21 133) Linear shapes: primary, secondary, quaternary. Primary structure is simply the sequence of covalently bonded amino acids in a peptide chain. Secondary structure is further bonding between nearby amino acids in a peptide chain, with the molecule still retaining a strand-like shape. Quaternary structure can involve separate linear polypeptide chains held together in a strand. Globular shapes: tertiary and quaternary. Tertiary structure involves bonding between distant amino acids, which causes the molecule to be wadded. Quaternary structure occurs when more than one globular peptide chain bonds together. 134) Enzymes and other globular proteins depend upon the three-dimensional shape resulting from the globular folding. Under conditions in which this shape is altered by denaturing agents such as heat, the protein ceases to function, though the primary and secondary structure may be unchanged. 135) The relatively low amount of oxygen and high carbon and hydrogen indicate that this compound is probably a lipid. Oral administration may result in digestion of the compound so that none is absorbed into the blood. Lipids are not highly soluble in water, and because blood is a watery medium, the injected lipid may not transport well in the blood. Also, human cells as well as the viruses may behave differently in culture compared to in a real patient. 136) Water molecules break the ionic bonds holding Na + and Cl- together. Each sodium ion becomes surrounded by polar water molecules, with the electronegative ends of water molecules interacting with the ion. Each chloride ion also becomes surrounded by polar water molecules, but in this case it is the electropositive ends of the water molecules that bind to the ion. A consequence is that sodium and chloride ions can function relatively independently of each other when in solution. 137) A 138) A 139) C 140) E 141) C 142) C 143) A 144) The atomic mass is the actual mass of an atom, expressed in atomic mass units (amu) or Daltons (Da), where 1 amu = 1.6 × 10-27 kg. However, molecular mass is the sum of the atomic mass of each element × the number of atoms of each atom that make up the molecule. 145) A. The mass of a molecule is determined by the mass of its component atoms. From the periodic table, the mass of Na is 23 amu and of Cl is nearly 36 amu, so the mass of one molecule of NaCl is 59 Da. A mole is like a dozen, i.e., it is a particular number of items, specifically 6.02 × 1023. B. A mole of NaCl = 59 Da × 6.02 × 1023 = 3.55 × 1025 Da. 1 Da = 1.66 × 10-27 kg, so 3.55 × 1025 Da × 1.66 × 10-27 kg/Da × 1000 g/kg = 59 g. C. A dozen NaCl molecules: 12 × 59 Da × 1.66 × 10-27 kg/Da × 1000 g/kg = 1.2 × 10-21 g. A dozen donuts: 12 × 30 g = 360 g. A mole of donuts: 6.02 × 1023 × 30 g = 1.8 × 1025 g. 146) C11H12N2 O2. The presence of the carboxylic acid (COOH) and amine (NH2 ) indicates this is an amino acid. Because of the R group structure, it is relatively nonpolar (this amino acid is tryptophan). 147) pH = 2.3. If pH = - log [H + ] and HCl is a strong acid, we can assume complete dissociation will occur in solution. 23  lOMoARcPSD|35516335 Exam Name___________________________________ Chapter 3 MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. 1) When cancer develops in one tissue and spreads to another through the blood or the lymph, the 1) cancer is said to have undergone what process? A) cytokinesis B) mutation C) metastasis D) differentiation 2) The space that is surrounded by the tissue wall of hollow organs is known as the 2) A) tract. B) extracellular space. C) lumen. D) peritoneal cavity. E) epidural space. 3) The lumen of a hollow organ such as the stomach is considered to be part of the ________ 3) environment. A) external B) internal 4) The watery medium that surrounds a cell is known as 4) A) protoplasm. B) cytoplasm. C) intracellular fluid. D) extracellular fluid. E) cytosol. 5) Which term is NOT used to define the structure that separates the contents of a human cell from its 5) surrounding medium? A) plasma membrane B) a cell wall C) a cell membrane D) plasmalemma E) All of the answers are correct. 6) Which of the following is NOT a function of membrane proteins? 6) A) respond to extracellular molecules B) act as transport molecules for various solutes C) creating junctions between cells D) anchor or stabilize the cell membrane E) produce energy 7) Cell membranes are said to be 7) A) impermeable barrier. B) selectively permeable barrier. C) freely permeable barrier. D) only permeable to water soluble molecules. E) None of the answers are correct. 1  lOMoARcPSD|35516335 8) What is/are the major role(s) of the phospholipid bilayer in the cellular membrane? 8) A) the formation of a barrier that is selective for lipid-soluble molecules B) the absorption of fats only C) to carry water-soluble molecules through a hydrophobic environment D) to provide a framework for membrane proteins only E) the formation of a barrier that is a selective for lipid-soluble molecules and to provide a framework for membrane proteins 9) Which of the following is NOT a membrane lipid? 9) A) phospholipids B) cholesterol C) sphingolipids D) All are membrane lipids. 10) Which structure is a lipid bilayer that controls which objects can leave or enter the cell? 10) A) Golgi apparatus B) ribosome C) plasma membrane D) endoplasmic reticulum E) nucleus 11) A liposome is a 11) A) a structural part of cell membranes. B) medium to deliver drugs. C) medium to deliver cosmetics. D) a type of lipid. E) a medium to deliver cosmetics and drugs. 12) An immunoliposome is a liposome that 12) A) can recognize cancer cells. B) suppresses the immune system. C) stimulates the immune system. D) None of the answers are correct. 13) Intermediate filaments 13) A) stabilize the position of organelles. B) transport materials within the cytoplasm. C) provide the cell with strength. D) form the neurofilaments in nerve cells. E) All of the answers are correct. 14) Which proteins assist in the movement of vesicles along microtubules? 14) A) kinesins B) rough endoplasmic reticulum C) Golgi complex D) mitochondria E) ribosomes 15) Which is an example of a membranous organelle? 15) A) cilia B) centriole C) ribosome D) cytoskeleton E) lysosome 2  lOMoARcPSD|35516335 16) The thickest protein fibers from the following group are 16) A) myosin molecules. B) microfilaments. C) neurofilaments. D) microtubules. E) keratin filaments. 17) Ribosomal RNA is formed by 17) A) lysosomes. B) nucleoli. C) the endoplasmic reticulum. D) mitochondria. E) Golgi complexes. 18) Which statement about mitochondria is FALSE? 18) A) The mitochondrial cristae form the inner membrane forming separate compartments. B) The mitochondria produce most of a cell's ATP. C) The intermembrane space plays an important role in mitochondrial ATP production. D) The mitochondria do not contain DNA nor RNA. E) The matrix of the mitochondria contains metabolic enzymes involved in energy production. 19)