exam 1 3204
101) The term polar is used to describe molecules because A) polar covalent molecules are found in colder climates. B) polar covalent molecules were first discovered in polar bears. C) there are at least two distinct ends of the molecule regarding electron position and the resulting charge. D) there are at least two distinct ends of the molecule regarding hydrogen placement. E) such molecules are always linear in shape.
Answer: C
108) A fatty acid that contains three double bonds in its carbon chain is said to be A) saturated. B) monounsaturated. C) polyunsaturated. D) hydrogenated. E) carboxylated.
Answer: C
109) Most of the lipid found in the human body is in the form of A) steroids. B) phospholipids. C) triglycerides. D) prostaglandins. E) monoglycerides.
Answer: C
12) How genetics influences the body's response to drugs is called A) pharmacokinetics. B) pharmacogenetics. C) pharmacogenomics. D) pharmacodynamics. E) pharmageddon.
Answer: C
140) A 5 M solution of 100 mL of glucose contains how many grams of glucose, molecular mass = 180 Daltons? A) 180 B) 360 C) 90 D) 6.02 × 1023 E) 1.0
Answer: C
142) How many grams of NaCl, molecular mass = 58.5 Daltons, are the molar equivalent to 90 g of glucose (molecular mass = 180 daltons)? A) 0.25 B) 0.5 C) 29.25 D) 117 E) 14.6
Answer: C
143) How many grams of NaCl, molecular mass = 58.5 Daltons, are necessary to make 1 liter of 5% saline? A) 58.5 B) 1 C) 50 D) 6.02 × 1023 E) 2.9
Answer: C
16) A placebo is A) any drug being tested in a clinical trial. B) any drug in a class of drugs commonly used as pain relievers. C) a drug or treatment that is expected to have no pharmacological effect. D) a nutritive and respiratory organ in fetal development. E) a hole in a cavity wall through which an organ protrudes.
Answer: C
17) The chemical bonding behavior of an atom is directly determined by the A) number of protons. B) number of neutrons. C) number and arrangement of electrons. D) size of the atom. E) mass of the atom.
Answer: C
18) A scientifically logical guess is a A) model. B) theory. C) hypothesis. D) law. E) variable.
Answer: C
23) The human environment is terrestrial, dry, and highly variable. However, our bodies expend enormous amounts of energy maintaining a constant internal environment. Studying why our bodies do this is what kind of scientific endeavor? A) mechanistic B) translational C) teleological D) anatomical E) meterological
Answer: C
11) Essential amino acids that are used to build proteins A) exist in twenty six different configurations. B) are linked together by ionic chemical bonds in proteins. C) can be used medically for both diagnosis and treatment of diseases. D) are derived from the foods we eat and digest. E) can only be made by cells within our bodies.
Answer: D
110) Each of the following is a function of proteins EXCEPT one. Identify the exception. A) binding to ligands B) transport C) catalyst D) storage of genetic information E) carrying of messages
Answer: D
111) If a polypeptide contains 10 peptide bonds, how many amino acids does it contain? A) 0 B) 5 C) 10 D) 11 E) 12
Answer: D
13) A positively-charged ion is called a(n) A) electron. B) proton. C) neutron. D) cation. E) anion.
Answer: D
15) The Internet database for molecular, cellular, and physiological information is called the ________ Project. A) Human Genome B) Physiognomy C) Physiosome D) Physiome E) Manhattan
Answer: D
19) The weak interactions between atoms that keep atoms near each other are called A) hydrogen bonds. B) van der Waals forces. C) ionic bonds. D) hydrogen bonds and van der Waals forces. E) van der Waals forces and ionic bonds.
Answer: D
22) Each amino acid differs from others in the A) number of central carbon atoms. B) size of the amino group. C) number of carboxyl groups. D) chemical structure of the R group. E) number of peptide bonds in the molecule.
Answer: D
24) Interactions between different globular or fibrous polypeptide chains result in which type of structure? A) primary B) secondary C) tertiary D) quaternary E) pentagonal
Answer: D
98) In a 5% NaCl solution, A) there are 5 grams of sodium chloride for every 100 mL of water. B) there are 5 grams of sodium chloride for every 100 mL of total solution. C) the solute is water. D) there are 5 grams of sodium chloride for every 100 mL of water and there are 5 grams of sodium chloride for every 100 mL of total solution. E) there are 5 grams of sodium chloride for every 100 mL of total solution and the solute is water.
Answer: B
Bloom's Taxonomy: Knowledge 75) When two or more atoms are chemically linked, the smallest unit of the resulting material is referred to as a(n) A) atom. B) molecule. C) element. D) nucleus. E) tissue.
Answer: B
10) Homeostasis is the ability of the body to A) prevent the external environment from changing. B) prevent the internal environment from changing. C) quickly restore changed conditions to normal. D) ignore external stimuli to remain in a state of rest. E) prevent excessive blood loss.
Answer: C
65) The law of mass balance states: A) if a substance is to remain constant any gain must be offset by an equal loss. B) that homeostasis can be maintained when the load of a substance is continuously lost. C) if one is to survive they must have a certain amount of mass. D) that all matter is neither created or destroyed. E) that all substances in the body have equal mass.
Answer: A
66) The protein keratin which is found in hair and nails and affords nails their rigid structure would be categorized as which of the following protein shapes? A) fibrous B) globular C) acidic D) hexavalent E) triangular
Answer: A
71) When glucose enters a cell it is phosphorylated in order to maintain a low glucose concentration in the cell. The enzyme that phosphorylates glucose would be what kind of modulator? A) covalent modulator B) competitive inhibitor C) allosteric modulator D) reversible antagonist E) irreversible agonist
Answer: A
74) The smallest unit of an element is a(n) A) atom. B) molecule. C) element. D) nucleus. E) tissue.
Answer: A
79) An element's ability to bind to and with other elements is determined by which of the following? A) the arrangement of electrons in the outer shell of an atom B) its amino acid composition C) its state of glycosylation D) the number of enzymes required E) the amount of folding in its subunits
Answer: A
8) Which of the following is one of Cannon's "internal secretions"? A) hormones B) nutrients C) water D) inorganic ions E) None of the answers are correct.
Answer: A
81) Ions with a negative charge are called A) anions. B) electrons. C) cations. D) neurons. E) tissues.
Answer: A
84) Molecules that do not dissolve well in water are called A) hydrophobic. B) hydrophilic. C) isotonic. D) polar. E) salts.
Answer: A
89) The purines found in DNA are ________ and ________. A) adenine, guanine B) ribose, thymine C) deoxyribose, guanine D) guanine, cytosine E) uracil, adenine
Answer: A
93) List the following in order of increasing mass: atom, molecule, proton, neutron, electron. A) electron < proton < neutron < atom < molecule B) neutron < proton < electron < atom < molecule C) electron < proton < atom < neutron < molecule D) proton < neutron < electron < atom < molecule E) atom < electron < proton < neutron < molecule
Answer: A
96) Which of the following elements combine to form nonpolar covalent bonds? A) carbon and hydrogen B) nitrogen and hydrogen C) sodium and chlorine D) hydrogen and oxygen E) carbon and chlorine
Answer: A
97) The designation Ca2+ means calcium has A) space for two more electrons. B) gained two more electrons. C) space for two more protons. D) gained two more protons.
Answer: A
How many grams of glucose, molecular mass = 180 Daltons, is necessary to make 1 liter of a 1.0 molar solution? A) 180 B) 360 C) 90 D) 6.02 × 1023 E) 1.0
Answer: A
41) Why is it necessary to label the axes of a graph?
Answer: A graph with no axis labels is meaningless—without knowing what trend is being illustrated, there is no communication of scientific information.
53) Which of the following results when an atom has such a strong attraction for electrons that it pulls one or more electrons completely away from another atom? A) a Van der Waals attraction B) an ionic bond C) a hydrogen bond D) a covalent bond E) a very stable bond
Answer: B
60) To which of the following groups of biomolecules do triglycerides and steroids belong? A) carbohydrates B) lipids C) proteins D) nucleotides E) lipids and proteins
Answer: B
67) Which of the following types of bonds between adjacent amino acids plays an important role in the shape of globular proteins? A) collagen bonds B) disulfide bonds C) sodium bonds D) metallic bond E) secondary bonds
Answer: B
68) Which of the following would be disrupted by changes in free hydrogen ions in solution, thus disrupting the molecule's shape and function? A) disulfide bonds B) hydrogen bonds C) sodium bonds D) covalent bonds E) double bonds
Answer: B
70) Which of the following best describes an irreversible antagonist? A) involved in activation via phosphorylation B) cannot be displaced by competition C) binds to proteins away from the active site D) reversible antagonist E) allosteric enhancer
Answer: B
72) If a reaction which is stopped by substance X can recover when a lot more of the native activator is supplied, substance X would be considered which of the following? A) covalent modulator B) competitive inhibitor C) allosteric modulator D) irreversible antagonist E) a phosphotase
Answer: B
8) Which of the following is a way to recognize a carbohydrate by looking at its name only? A) It ends in -ase. B) It ends in -ose. C) It begins with nucleo-. D) It begins with proteo-. E) It begins with lipo-.
Answer: B
83) Molecules that readily dissolve in water are called A) hydrophobic. B) hydrophilic. C) isotonic. D) non-polar. E) lipids.
Answer: B
88) The molecule RNA contains the five-carbon sugar A) lactose. B) ribose. C) deoxyribose. D) glucose. E) uracil.
Answer: B
90) The pyrimidines found in DNA are ________ and ________. A) adenine, guanine B) cytosine, thymine C) deoxyribose, guanine D) guanine, cytosine E) uracil, adenine
Answer: B
57) Which of the following biological molecules does glycogen belong to? A) carbohydrates B) lipids C) proteins D) nucleotides E) lipids and proteins
Answer: A
6) "Glucose is transported from blood into cells by transporters in response to insulin." This type of explanation is A) mechanistic. B) theological. C) teleological. D) metalogical. E) scatological.
Answer: A
62) The sequence and number of amino acids in the chain is an example of which of the following levels of protein structure? A) primary B) secondary C) teritiary D) quaternary E) alpha helix
Answer: A
64) Beta strands are an example of a spatial arrangement of amino acids. A) True B) False
Answer: A
50) All organic molecules contain which of the following? A) calcium B) carbon C) adenosine D) oxygen E) lipids
Answer: B
What is the pH of a 0.005 M HCl solution? Assume complete dissociation.
: pH = 2.3. If pH = - log [H+] and HCl is a strong acid, we can assume complete dissociation will occur in solution.
1) Physiology is the study of A) the structure of the body. B) the tissues and organs of the body at the microscopic level. C) growth and reproduction. D) the normal function of living organisms. E) the facial features as an indication of personality.
Answer: D
18) Atoms in a covalent molecule A) share electrons in single pairs. B) share electrons in double pairs. C) share electrons in triple pairs. D) share electrons singly, never in pairs. E) can share electrons in single pairs, double pairs, or triple pairs.
Answer: E
56) Van der Waals forces are weak attractive forces between the nucleus of one atom and the electrons of another atom close by. A) True B) False
Answer: A
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?
Answer: (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.
94) How many milliequivalents are represented by a mole of bicarbonate ions (HCO3-)?
Answer: 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.
99) A molecule of sucrose has a molecular weight of 342 Daltons. How many grams of sucrose would be required to make one liter of a 2.5 Molar solution of sucrose?
Answer: 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
103) Lipids are hydrophobic, and do not usually dissolve in water. Because blood is water-based, the lipid cholesterol is combined with ________ so that it can be transported by blood. A) hydrophilic molecules B) hydrophobic molecules C) nothing; cholesterol is not transported in blood D) cations E) anions
Answer: A
104) Only free H+ contributes to the hydrogen ion concentration. A) True B) False
Answer: A
106) Chemical reactions that occur in the human body proceed at a faster rate due to special catalytic molecules called A) enzymes. B) cytozymes. C) proteins. D) antibodies. E) antagonists.
Answer: A
13) A physician basing clinical decisions on primary research published in biomedical literature is doing ________ medicine. A) evidence-based B) traditional C) alternative D) whimsical E) holistic
Answer: A
14) The most important polar molecule is ________ because it is practically a universal solvent. A) water B) bicarbonate C) sodium chloride D) magnesium sulfate E) nucleic acid
Answer: A
15) A molecule referred to as highly soluble is A) very likely to dissolve in water. B) not very likely to dissolve in water. C) called aqueous. D) very likely to dissolve in water and is called aqueous. E) not very likely to dissolve in water and is called aqueous.
Answer: A
17) A technique used to resolve contradictory results in scientific studies is A) meta-analysis. B) retrospective analysis. C) prospective analysis. D) cross-sectional analysis. E) longitudinal analysis.
Answer: A
2) Glycosylated molecules are those formed with which group of organic compounds?A) lipids B) nucleic acids C) lysosomes D) cholesterol E) DNA
Answer: A
3) Cells regulate their level of activity by regulating the amount of proteins present in the cell at any given time, so an up regulation of enzymes would be expected to A) increase the cell's response that is produced by the reaction catalyzed by the enzyme. B) decrease the level of productivity of chemical reactions that rely on them. C) have no effect on the rate of reactions catalyzed by the enzymes. D) decrease the rate of reactions catalyzed by the enzymes. E) both decrease the level of productivity of chemical reactions that rely on them and decrease the rate of reactions catalyzed by the enzymes.
Answer: A
31) Polymers are a typical formation of ________ molecules. A) organic B) inorganic C) either organic or inorganic
Answer: A
32) You want to display data on the finish times of the 10 fastest race horses in a single race at the Kentucky Derby. Which type of graph would be best to display this information? A) bar graph B) line graph C) scatter plot
Answer: A
4) When an enzyme reaches its saturation point, the amount of A) substrate for the enzyme to act upon is very high. B) substrate for the enzyme to act upon is very low. C) product produced continues to increase. D) product produced by the enzyme decreases. E) substrate for the enzyme to act upon is very low and the amount of product produced by the enzyme decreases.
Answer: A
40) The identity of an element can be determined by the number of A) protons. B) neutrons. C) electrons. D) carbon atoms. E) double bonds.
Answer: A
41) This particle has a charge of +1 and a mass of 1. A) proton B) neutron C) electron D) molecular oxygen E) sodium chloride
Answer: A
45) A blood pH of less than 7.00 and greater than 7.70 is incompatible with life. A) True B) False
Answer: A
47) HCl (hydrochloric acid) is considered an acid because A) in solution it donates its H+. B) in solution it decreases the concentration of free H+. C) in solution it increases the pH. D) it is similar to ammonia. E) it is able to form hydroxide ions
Answer: A
51) Molecules that contain the element carbon are known as A) organic molecules. B) essential elements. C) nucleic acids. D) protons. E) vitamins.
Answer: A
38) What is the difference between a peer-reviewed article and a review article?
Answer: 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.
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.
Answer: 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.
1) Stanley Miller set out to demonstrate an explanation for the origins of organic molecules using a combination of simple organic molecules, heat and periodic bursts of electricity through the mixture, ultimately producing which kind of molecules?A) carbohydratesB) amino acidsC) lipidsD) glycoproteinsE) nucleic acids
Answer: B
100) A double covalent bond is formed when atoms A) share one pair of electrons (a total of two). B) share two pairs of electrons (a total of four). C) swap two pairs of electrons. D) transfer a pair of electrons from one atom to the other. E) transfer two pairs of electrons from one atom to the other.
Answer: B
105) In the equation CO2 + H2O ↔ H2CO3 ↔ H+ + HCO3-, which of these is an acid? A) HCO3- B) H2CO3 C) H2O D) CO2 E) H+
Answer: B
11) Oxytocin is a hormone that is released in response to cervical dilation. It in turn causes more uterine contractions that will further dilate the cervix. Which type of feedback loop does oxytocin trigger? A) negative feedback B) positive feedback C) local control D) nociceptive feedback
Answer: B
12) Which of the following are examples of cations? A) SO42- B) Ca2+ C) HPO42- D) HCO3- E) Cl-
Answer: B
14) A study in which a participant acts as an experimental subject in part of the experiment and a control in another part of the experiment is called a ________ study. A) double-blind B) crossover C) meta-analysis D) retrospective
Answer: B
141) If 100 mL of water contains 5 grams of NaCl, molecular mass = 58.5 Daltons, what is the molarity of the solution in moles/L? A) 0.05 B) 0.85 C) 2.92 D) 0.085 E) 0.25
Answer: B
19) If a scientific model is supported or verified repeatedly by multiple investigators, it may become a A) model. B) theory. C) hypothesis. D) law. E) variable.
Answer: B
2) The literal meaning of the term physiology is knowledge of A) organs. B) nature. C) science. D) chemistry. E) math.
Answer: B
21) In regard to lipids, the term unsaturated refers to A) the lack of double bonds between adjacent carbon atoms in a fatty acid. B) the presence of double bonds between adjacent carbon atoms in a fatty acid. C) the ring structure of steroids. D) glycerol, which acts as an anchor for joined fatty acids. E) fats, such as butter and lard, which come from animal sources.
Answer: B
21) You are interested in learning more about Parkinson's disease, a neurological disorder that primarily affects motor function. Which is the best source to begin your investigation? A) Ask.com B) MedlinePlusPubMed C) public library D) physiology textbook E) a physician
Answer: B
22) Which of the following systems does NOT exchange material with the internal and external environments? A) respiratory system B) circulatory system C) digestive system D) urinary system E) All of the above.
Answer: B
23) The alpha-helix and pleated sheet are examples of the ________ structure of a protein. A) primary B) secondary C) tertiary D) quaternary E) pentanary
Answer: B
28) Adaptive significance is an important concept in physiology because it describes the A) importance of a highly variable external environment. B) physiological functions that promote an organism's survival. C) ability of an organism to monitor and restore its internal state to normal conditions when necessary. D) similarities between ancient and modern marine organisms. E) parameters necessary to maintain a constant internal environment.
Answer: B
3) Because anatomy and physiology have different definitions, they are usually considered separately in studies of the body. A) True B) False
Answer: B
34) 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 time changes with experience. You set up a graph to display the race finish times of this horse. Which type of graph would be best to display the race finish times of this horse? A) bar graph B) line graph C) scatter plot
Answer: B
34) Which of the following substances is most alkaline? A) lemon juice, pH = 2 B) urine, pH = 6 C) tomato juice, pH = 4 D) white wine, pH = 3 E) stomach secretions, pH = 1
Answer: B
35) If a substance has a pH that is less than 7, it is considered A) neutral. B) acidic. C) alkaline. D) a buffer. E) a salt.
Answer: B
37) Which of the following is a common feature of soluble proteins? A) structural support B) noncovalent interaction C) receptor binding D) chemical modulation E) All of the answers are correct.
Answer: B
39) Isotopes of the same element differ by having different numbers of A) protons. B) neutrons. C) electrons. D) carbon atoms. E) double bonds.
Answer: B
43) This particle has a neutral charge and a mass of 1. A) proton B) neutron C) electron D) hydrogen E) magnesium
Answer: B
49) Which of the following formulas describes the relationship between pH and hydrogen ions? A) pH = log [H+] B) pH = -log [H+] C) [H+] = -log pH D) [H+] = log pH E) pH= [H+] + [OH-]
Answer: B
24) Individuals with Type I diabetes do not make enough insulin. Which of the following would be a mechanistic explanation of how insulin is used by the body? A) Cells need insulin because glucose will not cross the cell membrane. B) Insulin is a hormone involved in glucose transport. C) Insulin binds to its receptor which triggers the movement of glucose transporters to the cell membrane. D) Since all cells need glucose, insulin is required. E) Without insulin most cells in the body would be unable to produce enough
Answer: C
29) You conduct an experiment on twenty 18-year-old male subjects to see how various intensities of exercise influence heart rate. Which of the following is/are considered an independent variable? A) age of subjects B) sex of subjects C) intensity of exercise D) heart rate E) More than one of the answers is correct.
Answer: C
36) Protein specificity is the A) activation of a specific protein that is needed to perform a particular function. B) degree to which a protein is attracted to a ligand. C) ability of a protein to bind a certain ligand or a group of related ligands. D) degree to which a protein-ligand complex initiates a response. E) degree to which a protein is attracted to a ligand and the ability of a protein to bind a certain ligand or a group of related ligands.
Answer: C
36) There are 10 cloned horses, born on the same day, with identical chromosomes. They are each subjected to the same physical training regimen, but given daily injections of different concentrations of a particular vitamin. They all run the same race. You set up a graph to explore a relationship between race finish time and vitamin dose. Which type of graph is best to explore a relationship between race finish time and vitamin dose? A) bar graph B) line graph C) scatter plot
Answer: C
38) An ion has gained or lost A) a proton(s). B) a neutron(s). C) an electron(s). D) a carbon atom(s). E) a double bond.
Answer: C
4) The following is a list of several levels of organization that make up the human body. 1. tissue 2. cell 3. organ 4. molecule 5. organism 6. organ system The correct order from the smallest to the largest is A) 2, 4, 1, 3, 6, 5. B) 4, 2, 1, 6, 3, 5. C) 4, 2, 1, 3, 6, 5. D) 4, 2, 3, 1, 6, 5. E) 6, 4, 5, 2, 3, 1.
Answer: C
42) This particle has a charge of -1 and a negligible mass. A) proton B) neutron C) electron D) hydrogen E) magnesium
Answer: C
46) Which of the following statements best describes the relationship between pH and hydrogen ions? A) pH and hydrogen ions are equivalent. B) pH and hydrogen ions are directly proportional. C) pH and hydrogen ions are inversely proportional. D) pH is always 100 times more than the number of hydrogen ions. E) pH and hydrogen ions are independent and unrelated.
Answer: C
5) "Glucose is transported from blood into cells because cells require glucose to meet their energy needs." This type of explanation is A) mechanistic. B) theological. C) teleological. D) metalogical. E) scatological.
Answer: C
52) Which of the following combination of elements make up 90% of the body's mass? A) oxygen, carbon, and nucleic acids B) hydrogen, nitrogen, and oxygen C) oxygen, carbon, and hydrogen D) carbon dioxide, oxygen, and sodium E) sodium, potassium, and calcium
Answer: C
54) These are weak attractive forces that are responsible for the surface tension of water. A) a Van der Waals attraction B) an ionic bond C) a hydrogen bond D) a covalent bond E) a potassium bond
Answer: C
59) Which of the following biological molecules exhibit the characteristics of saturation, specificity and competition? A) carbohydrates B) lipids C) receptor proteins D) nucleotides E) lipids and proteins
Answer: C
63) Hemoglobin molecules are made from four globular protein subunits. The three-dimensional shape of these globular subunits would be an example of which of the following levels of protein structure? A) primary B) secondary C) teritiary D) quaternary E) alpha helix
Answer: C
65) Which of the following levels of protein structure occurs from spontaneous folding that results from covalent bonds and noncovalent interactions? A) primary B) secondary C) teritiary D) quaternary E) triangular
Answer: C
67) ________ are kept within normal range by physiological control mechanisms which are used if the variable strays too far from its ________. A) Setpoints, regulated variable B) Independent variables, steady state C) Regulated variables, setpoint D) Dependent variables, lowest value E) Steady state values, integrating center
Answer: C
69) Which of the following are used to keep our systems at or near their setpoints? A) positive feedback loops B) response loops C) feedback loops D) open control loops E) feedforward control loop
Answer: C
73) Which of the following would be considered an allosteric modulator? A) A substance involved in activation via phosphorylation. B) A substance that can be displaced by competition at the active site. C) A substance that binds to proteins away from the active site. D) A substance that has no effect on the affinity of the ligand. E) A substance that binds irreversibly.
Answer: C
76) A(n) ________ is a substance that consists entirely of atoms with the same atomic number. A) atom B) molecule C) element D) nucleus E) tissue
Answer: C
80) Ions with a positive charge are called A) anions. B) electrons. C) cations. D) neurons. E) tissues.
Answer: C
82) A ________ is a homogeneous mixture containing a solvent and a solute. A) nucleus B) molecule C) solution D) compound E) cocktail
Answer: C
87) The molecule DNA contains the five-carbon sugar A) lactose. B) ribose. C) deoxyribose. D) glucose. E) uracil.
Answer: C
9) Which of the following is NOT considered an essential element for a living organism? A) carbon B) hydrogen C) mercury D) oxygen E) nitrogen
Answer: C
91) In a chemical reaction, ________ between atoms are broken as atoms are rearranged in new combinations to form different chemical substances. A) electron shells B) nuclei C) chemical bonds D) homeostatic interactions E) protons
Answer: C
25) Excretion is a function of the body. Which of the following would be considered excretion? A) Movement of sodium from the intestines to the bloodstream. B) Movement of glucose from the kidney to the blood stream. C) Movement of potassium from kidney cells into one's urine. D) Movement of salt from sweat glands to the surface of the skin. E) Movement of oxygen from the lungs to the blood stream.
Answer: D
25) The concentration of a solution expresses the amount of A) solvent per volume of solute. B) solute per volume of solvent. C) solvent per volume of solution. D) solute per volume of solution. E) None of the answers are correct.
Answer: D
27) A nucleotide consists of a A) five-carbon sugar and phosphate group. B) five-carbon sugar and a nitrogenous base. C) phosphate group and a nitrogenous base. D) five-carbon sugar, a nitrogenous base, and a phosphate group. E) five-carbon sugar and an amino acid.
Answer: D
29) The most important energy-transferring compound in cells is a nucleotide known as A) glucose. B) fructose. C) protein. D) adenosine triphosphate. E) deoxyribonucleic acid.
Answer: D
30) Which bases below are purines? 1. adenine 2. cytosine 3. guanine 4. thymine 5. uracil A) 1 and 2 B) 2 and 3 C) 1, 3, and 5 D) 1 and 3 E) 2, 4, and 5
Answer: D
30) You conduct an experiment on twenty 18-year-old male subjects to see how various intensities of exercise influence heart rate. Which of the following is/are considered a dependent variable? A) age of subjects B) sex of subjects C) intensity of exercise D) heart rate E) More than one of the answers is correct.
Answer: D
32) Cholesterol is a A) precursor to steroid hormones. B) structural component of cell membranes. C) dangerous fat that is absent from a healthy body. D) precursor to steroid hormones and a structural component of cell membranes. E) precursor to steroid hormones, a structural component of cell membranes, and a dangerous fat that is absent from a healthy body.
Answer: D
33) A component of an important buffer in the human body is A) NaCl. B) H+. C) HCl. D) HCO3-. E) H2O.
Answer: D
44) A change in pH value of one unit indicates a A) 1-fold change in [H+]. B) change of 10-1 in pH. C) change of 10-2 in pH. D) 10 fold change in [H+]. E) Cannot be determined.
Answer: D
55) These result when the carbon atoms in phospholipids share a pair of electrons. A) a Van der Waals attraction B) an ionic bond C) a hydrogen bond D) a covalent bond E) a potassium bond
Answer: D
58) Nucleotides participate in which of the following functions? A) They combine with oxygen to produce energy. B) They are the building blocks of proteins like cell receptors. C) They form structural elements in the cell membrane. D) They transfer energy and are part of genetic material. E) They store glucose as fat.
Answer: D
61) Potassium channels are usually composed of several subunits. This is an example of which level of protein structure? A) primary B) secondary C) teritiary D) quaternary E) alpha helix
Answer: D
68) The vasodilation of blood vessels surrounding muscles due to the production of carbon dioxide during exercise is an example of which of the following? A) neural control B) long-distance control C) reflex control D) local control E) hormonal control
Answer: D
69) During intense exercise our muscles produce lactate and hydrogen ions. Which of the following molecules would be affected by the accumulation of hydrogen ions? A) cholesterol in the plasma membrane B) glucose molecules in the adipose tissue C) DNA in the nucleus D) the proteins actin and myosin E) phospholipids in the membrane
Answer: D
7) Chromium is A) not an element in the periodic table. B) a protein. C) a dietary supplement with no natural role in the body. D) an essential element involved in glucose metabolism.
Answer: D
7) Which of the following is a buffer zone between the outside world and most of the cells of the body? A) cell membrane B) red blood cells C) intracellular fluid D) extracellular fluid E) All of the answers are correct.
Answer: D
77) The center of an atom is called the A) proton. B) molecule. C) element. D) nucleus. E) electron.
Answer: D
85) A(n) ________ is any molecule or ion that binds to another molecule. A) phospholipid B) enzyme C) vitamin D) ligand E) cofactor
Answer: D
9) The study of body function in a disease state is A) necrology. B) physiology. C) microbiology. D) pathophysiology. E) histology.
Answer: D
92) The reaction rates of many chemical reactions that occur in the body are controlled by special protein molecules called A) neurotransmitters. B) purines. C) nucleic acids. D) enzymes. E) intermediates.
Answer: D
10) The largest carbohydrate molecules are called polysaccharides because they are composed of ________ molecules bonded together with one another. A) amino acid B) nucleotide C) purine D) pyrimidine E) simple sugar
Answer: E
107) The fuel molecule cells use to run all their activities is A) sucrose. B) starch. C) protein. D) vitamins. E) glucose.
Answer: E
112) Glycoprotein molecules A) act as buffers in body fluids. B) increase the solubility of lipids. C) allow atoms to pack closely together and occupy minimum space. 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.
Answer: E
144) A typical blood concentration of glucose is 100 mg/dL. The molecular weight of glucose is approximately 180 Daltons. What is the molarity of this solution in millimoles? A) 100 B) 10 C) 0.56 D) 18 E) 5.6
Answer: E
145) If in an acid-base reaction H2SO42- donates two H+, one mole of H2SO42- would equal how many equivalents? A) 0.75 B) 1 C) 4 D) 0.5 E) 2
Answer: E
16) A free radical is a A) charged particle. B) molecule with an extra electron. C) molecule with an extra neutron. D) molecule with an extra proton. E) molecule with an unpaired electron.
Answer: E
20) All of these statements about carbohydrates are true EXCEPT one. Identify the exception. A) Simple sugars include galactose, glucose, and ribose. B) Cellulose is the most abundant polysaccharide on earth. C) Glycogen is a storage polysaccharide made by animal cells. 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.
Answer: E
20) Place these terms in the typical sequence in which they appear in the process of scientific inquiry: experimental data, theory, model, observation, hypothesis, replication. A) experimental data, theory, model, observation, hypothesis, replication B) replication, hypothesis, experimental data, theory, model, observation C) theory, observation, experimental data, hypothesis, replication, model D) observation, replication, model, experimental data, hypothesis, theory E) observation, hypothesis, experimental data, replication, model, theory
Answer: E
26) Nucleic acids are polymers of units called A) amino acids. B) fatty acids. C) bases. D) ribose. E) nucleotides.
Answer: E
28) According to the rules of complementary base pairing, a nucleotide containing the base cytosine would only pair with a nucleotide containing the base A) thymine. B) adenine. C) uracil. D) cytosine. E) guanine.
Answer: E
48) Molecular function and distinctive shapes of large complex biomolecules result from the interactions of which of the following? A) van der Waals forces B) ionic bonds C) hydrogen bonds D) covalent bond angles E) All of the choices can contribute.
Answer: E
5) Which group of elements makes up more than 90% of the body's mass? A) O, H, Na B) C, Na, K C) O, Ca, H D) Ca, C, O E) O, C, H
Answer: E
6) The organic molecules known as phospholipids are key components of cell membranes and composed of which molecules? A) amino acids B) nucleotides C) glycerol D) fatty acids E) both glycerol and fatty acids
Answer: E
66) Mass balance involves determining the total amount of a substance in the body. We can determine the rate of production (i.e. Mass Flow) of this substance by which of the following formulas? A) intake + production - excretion - metabolism. B) (amount of substance / min) × (concentration of the substance) C) volume of flow / (amount of substance / min) D) (concentration of a substance) / volume flow E) (concentration of a substance) × (volume/min)
Answer: E
78) Electrons travel around the center of the atom at high speed forming a(n) A) atom. B) molecule. C) element. D) nucleus. E) shell.
Answer: E
86) Two methods of protein activation include ________ and ________. A) exergonic, endogonic B) enzymatic, glycolytic C) homeostatic, osmotic D) mechanistic, covalent bonding E) proteolytic, cofactor binding
Answer: E
42) Why is it necessary to space grid marks on a graph proportionally to the quantity measured (example: each square represents one centimeter)?
Answer: If this is not done, a trend would be obscured or even misrepresented.
26) What is a placebo effect?
Answer: It is the phenomenon whereby a patient who has been informed of the side effects of a drug he 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.
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?
Answer: 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.
120) Compare and contrast the general chemical structures of monosaccharides and amino acids.
Answer: 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).
40) Sarah 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 Sarah's long flights and her insomnia are related to biological rhythms?
Answer: Our sleep-wake cycle is a biological rhythm that lets our body know when it is time to rest. Most likely Sarah 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.
51) You are designing a study to assess the effects of a new drug treatment for hypertension. In your study of this drug's efficacy in treating hypertension, your subjects are white males, ages 40 to 60 years. Is your study applicable to all people? Explain.
Answer: 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.
39) What is the major problem with the deconstructionist view of biology?
Answer: Return to the topic of function and process. 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.
121) What are functional groups? List the most common functional groups found in biological molecules.
Answer: Several combinations of atoms that occur repeatedly in biological molecules
48) Write a teleological explanation for why heart rate increases during exercise. Now write a mechanistic explanation for the same phenomenon.
Answer: 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).
114) What is the induced-fit model? List the types of bonds involved and classify them as strong or weak.
Answer: 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).
102) What makes fats solid at room temperature? 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?
Answer: 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.
43) Explain why the prefix homeo- is used in the term homeostasis. Why do some physiologists prefer the term homeodynamics over homeostasis?
Answer: 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.
List and briefly describe the seven categories of soluble proteins.
Answer: The seven categories: enzymes, membrane transporters, signal molecules, receptors, binding proteins, regulatory proteins, and immunoglobulins. See the "Protein Interactions" section of the chapter.
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?
Answer: The x-axis is horse name or number; the y-axis is finish time in minutes.
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 time changes with experience. You set up a graph to display the race finish times of this horse. What would the labels be for the graph axes?
Answer: The x-axis is race number or date; the y-axis is finish time in minutes.
37) There are 10 cloned horses, born on the same day, with identical chromosomes. They are each subjected to the same physical training regimen, but given daily injections of different concentrations of a particular vitamin. They all run the same race. You set up a graph to explore a relationship between race finish time and vitamin dose. What are the labels for the graph axes?
Answer: The x-axis is vitamin dose; the y-axis is finish time in minutes.
113) Compare and contrast the role of up-regulation and down-regulation of proteins.
Answer: 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.
52) High cholesterol levels have been shown to be a contributing factor to heart disease and death due to cardiovascular disease 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 a town called Framingham, Massachusetts. This study became known as the Framingham Study, and it is very well known because it did not support the hypothesis that giving cholesterol-lowering medications would reduce the risk of developing or dying from cardiovascular disease. 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 pertains to human studies? You can find a copy of the study online and read it, if necessary.
Answer: 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.
49) What is a hypothesis? What are the steps involved in following the scientific method? How does one distinguish the dependent variable from the independent variable in an experiment? How are each of these represented on a graph?
Answer: This is discussed in "The Science of Physiology" section of the chapter and in Figure 1.15.
31) Why are physiology and anatomy frequently studied together?
Answer: This is discussed in the "Physiology Is an Integrative Science" section
47) Provide an example of a control system. Be sure to include the three main components: an input signal, a controller, and an output signal.
Answer: 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.
117) Solutions are formed with water and ________ solutes which dissolve in them.
Answer: hydrophilic
116) When a nitrogenous base is bonded to a pentose sugar and a phosphate, a ________ is formed.
Answer: nucleotide
115) The ________ of a solution is the negative logarithm of the hydrogen ion concentration, expressed in moles per liter of solution.
Answer: pH
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.
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.
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.
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.
True or False? Lipids are considered hydrophobic because they easily dissolve in water. If true what allows them to dissolve in water or if not, what is it about their molecular structure that makes them less likely to dissolve in water?
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.
Sally does not understand the differences between ions, isotopes, and free radicals. Assuming she has learned and understood some basic chemistry, what is the likely source of her confusion? Review the definitions of these terms, then make a table or flow chart to help her sort this out.
Her confusion may arise from the fact that all of these terms describe a structure that has either gained or lost something. 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.
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?
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.
Ionic bonds are considered to be strong chemical bonds. Yet, ions dissociate in water. Explain this apparent contradiction.
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.
Your roommate is not a science major but is interested in science and asks you to verify a rumor he has heard: it is theoretically possible for two people to walk through each other without causing harm. Confirm or refute what he has heard, and explain.
People are composed of molecules, which are in turn composed of atoms. Each atom is mostly empty space, because the protons, neutrons, and electrons are extremely tiny, and the electrons are relatively distant from each other and from the nucleus. A scientist acknowledges that there is often a finite probability, however small, that a very unlikely event could happen. If all of each person's subatomic particles were aligned just right, they could move through the other person's empty atomic space. This is so unlikely as to be practically impossible, however.
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.
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.
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?
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.
What is the difference between atomic mass and molecular mass
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.
119) Compare and contrast the chemical bonds between adjacent monomers in DNA, and between two strands of DNA.
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.
Explain the polar character of an ammonia molecule (NH3). What is the cause of the partial charges? What is the overall charge for NH3?
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.
118) The ________ molecules which form the bilayer region of the cell membrane exhibit hydrophilic properties on the outer surface and hydrophobic properties on the inner surface.
phospholipid