BIOL 213 FINAL EXAM BANK: EXAM 1: EXAM 1 HW: 1. If phosphorus-32 has an atomic number of15, how many neutrons does it usually have? - 17 2. The seed of a
... [Show More] desert plant may be dormant for many years without growing, but is still considered to be alive because it? - Possesses heritable information 3. A “rogue” scientist is featured in many movies, but actual scientific discovery and advancement is done as a community, involving lots of dedicated scientists. Once a hypothesis has been supported in many ways and is accepted by the scientific community as fact, it now considered a? - Theory 4. Your pet chameleon changes color depending on its environment. You think this is because it can respond to how much heat it absorbs from whatever it is sitting on. In scientific terms, your thoughts are a(n)? - Hypothesis 5. The atomic weight of carbon is 12.011. Its mass number is 12.000. Why are these two values slightly different? - Atomic weight is the average of the mass numbers of a representative sample of the element, including all its isotopes. 6. Which of the following statements about the atom is true? - In an atom with a neutral charge, the number of electrons is equal to the number of protons. 7. Which component of an atom does not significantly add to its mass? - Electron 8. Nitrogen, oxygen, hydrogen, and carbon make up approximately how much of the living mass on earth? - 99% 9. Which of the following is the most basic structural and physiological unit of all living organisms? - Cell 10. H2SO4 can ionize completely to yield two H+ ions and one SO42- ion. H2SO4 is therefore a - Strong acid 11. The ability of an atom to combine with other atoms is determined by the atom's - Valence electron shell Contact: [email protected] 12. All of the following are nonpolar except for - NaCl 13. Two characteristics of water make it different from most other compounds: Its solid state is _______ its liquid state, and it takes up _______ heat as it changes to its gaseous state. - less dense than; large amounts of 14. The two covalent bonds in a water molecule are polar because - oxygen is more electronegative than hydrogen. 15. Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, the H+ ions are used up as they combine with the bicarbonate ions. When this happens, the pH of the blood - Does not change 16. A covalent bond is formed by the sharing of _______ between atoms, whereas an ionic bond is formed by the _______. - electrons; transfer of electrons from one atom to another 17. To determine the number of molecules in a teaspoon of sugar you have to know - the weight and molecular weight of the sugar, and Avogadro's number. 18. Oxygen forms _______ covalent bond(s), carbon forms _______, and hydrogen forms _______ - Two;four;one 19. Which of the following compounds containing 1H, 12C, and/or 16O has the greatest number of molecules in a sample with a mass of 2 grams? - Water (H20) 20. Aldehydes and ketones are very similar in that they both contain? Selected Answer: a carbonyl group (C=O). 21. During the formation of a peptide linkage, a(n) _______ is formed. - molecule of water 22. In condensation reactions, the atoms that make up a water molecule are derived from? - both reactants. 23. All of the following amino acids have an optical isomer except for? - glycine. 24. If all of the cysteine residues of a protein were changed to threonine, then? - the protein would lose disulfide bond formation, which would affect its tertiary structure. 25. Amino and carboxyl functional groups tend to form bases and acids by gaining or losing? - a proton. 26. Each amino acid has a unique _______ group. - “R”. 27. What do polysaccharides, polypeptides, and polynucleotides have in common? - They are broken down in hydrolysis reactions 28. Leucine and valine have side chains that do not interact with water; therefore, they? - are nonpolar. 29. An essential functional group involved in cellular energy transfer is the _______ group. - phosphate. 30. What is the difference between α-glucose and β-glucose? - They differ in the placement of their OH and H groups. 31. Which of the following are true of starch and glycogen, which are both polysaccharides. Starch is _______, whereas glycogen _______. - an energy storage compound of plants; an energy storage molecule of animals. 32. A β pleated sheet organization in a polypeptide chain is an example of _______ structure. - Secondary 33. The primary structure of a folded protein is determined by? - the sequence of its amino acids 34. A molecule with the formula C15H30O15 is a - Carbohydrate 35. Researchers find that removing an enzyme from a neutral pH environment and placing it in an acidic pH environment causes a loss of activity. However, when the enzyme is returned to its original neutral pH, its activity has doubled from its original state. What is one possible explanation for this observation? - The enzyme has refolded differently due to an absence of chaperones, and now the active site is more available to the substrate. 36. Glucose and fructose both have the formula C6H12O6, but the atoms in these two compounds are arranged differently. Glucose and fructose are therefore? - isomers. 37. A type of protein that functions by helping other proteins fold correctly is called a - Chaperone 38. Peptide chains have a(n) _______ and a(n) _______ end. - N terminus; C terminus. 39. The magnesium chelatase protein has quaternary structure. This means that magnesium chelatase - is composed of multiple peptide subunits 40. Which of the following statements about fatty acids molecules is true? - They are composed of hydrocarbon tails and a carboxyl group 41. Nucleotides in RNA are connected to one another in the polynucleotide chain by _______ bonds between _______. - phosphodiester; a sugar and a phosphate group. 42. Miller and Urey’s 1954 hot chemistry experiment was based on the assumption that Earth’s early atmosphere contained water (H2O) vapor, methane, hydrogen, and ammonia. Subsequent research showed that volcanoes released carbon dioxide (CO2), hydrogen sulfide (H2S), and sulfur dioxide (SO2) around 4 billion years ago. This discovery suggests that? - Earth’s early environment included these gases as well. 43. If you chew a cracker long enough, it eventually tastes sweet. This is because the amylase enzyme in your saliva is? - breaking down the starch into monosaccharides 44. Which of the following statements concerning genetic information in most cells is true? - The flow of information in a cell is from DNA to RNA to protein. 45. Lipids play an important role in a number of functions. Which of the following is not one of those functions? - Storing of genetic information 46. Ribose and deoxyribose are both found in nucleic acids. The difference between ribose and deoxyribose is that? - both a and b are true 47. A nucleotide contains a pentose sugar, a phosphate group, and a(n)? - nitrogen-containing base. 48. Which of the following is least likely to dissolve in water? - a lipid 49. A molecule that has an important role in limiting what gets into and out of cells is? - phospholipid. EXAM 1 ONLINE RESOURCE: 1. The simplest level of biological organization at which something can considered “Life” is? a. atoms b. molecules c. cells d. tissues e. ecosystems 2. The main purpose of any single experiment is to a. explain an observation. b. prove unambiguously that a particular hypothesis is correct. c. give know-it-all college professors something to do. d. answer as many key questions as possible. e. test a prediction that is based on a hypothesis. 3. Metabolism is a. the consumption of energy only. b. the release of energy only. c.. the exchange of nutrients and waste products with the environment. d. the production of heat by chemical reactions. e. all conversions of matter and energy taking place in an organism 4. The part of the atom that carries a positive charge is the a. proton. b. electron. c. neutron. d. megatron. e. nucleus. 5. The atomic number of an element is the same as the number of _______ in each atom. a. neutrons b. Protons c. protons plus electrons d. neutrons plus protons e. neutrons plus electrons 6. An atom with additional neutrons has a larger atomic mass and can undergo radioactive decay. They are known as? a. chaperones b. isotopes. c. variants d. isoforms e. none of the above are correct 7. The element Nitrogen is found in the second row of the periodic table and has an atomic number of 7. How many electrons must Nitrogen gain in order for its valence shell to be full? a. 0 b. 2 c. 3 d. 7 e. 8 8. Which of the following bonds is formed when atoms share electrons unequally? a. non-polar covalent b. polar covalent c. cationic d. anionic e. van der waals force 9. Which of the following are special properties of water? a. It has a high (large) heat capacity. b. Its molecules form hydrogen bonds with themselves and solutes. c. It dissolves all four classes of biological molecules (nucleic acids, proteins, lipids, and carbohydrates). d. Answers A and B are correct e. All of the above are correct. 10. How would you make 1 liter of an aqueous solution with a 0.5 M concentration of a compound that has a molecular weight of 200 daltons (grams)? a. Add 0.20 grams of the compound to 1000 ml of water. b. Add 200 grams of the compound to 1000 ml of water. c. Measure out 200 grams of the compound and add water until the volume equals 1000 ml. d. Measure out 100 grams of the compound and add water until the volume equals 1000 ml. e. Measure out 0.5 grams of the compound and add water until the volume equals 1000 ml. 11. Assuming you have made the solution preceding question correctly, how many molecules of the compound are in the 1 liter of solution? a. 0.5 b. 100 c. 3.011 x 1023 d. 200 e. cannot be determined from information given 12. A soft drink may have an H+ concentration of 10–3 mol/L. The pH of this drink is? a. 0.001. b. –3. c. 0. d. 3. e. 1,000 13. Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, more H+ ions combine with the bicarbonate ions. When this happens, the pH of the blood? a. becomes significantly more basic. b. becomes significantly more acidic. c. does not significantly change. d. Answers A and B are correct. e. All of the above are correct. 14. Which of the following functional groups is a weak acid? a. carboxyl b. amino. c. hydroxyl. d. phosphate. e. ketone. 15. Which statements regarding a 2-carbon molecule with an amino functional group is/are TRUE? a. It is a weak acid b. It is a weak base. c. It is non-charged and non-polar. d. It will be hydrophobic e. All of the above are true. 16. Which of the following is a correct monomer/polymer pairing? a. Monosaccharide/phospholipid b. Amino acid/protein c. Triglyceride/cellulose d. Nucleotide/steroid e. Monosaccharide/DNA 17. During a condensation reaction in which two monosaccharides are joined to form a disaccharide, a(n) ___?____ bond is formed. a. glyosidic bond b. peptide bond c. phosphodiester bond d. answers A and B are correct e. all of above are correct 18. Which of the following can have enzymatic activity? a. RNA. b. proteins. c. carbohydrates d. answer A and B are correct e. all of the above are correct 19. Which of the following amino acid(s) is unique in that it does NOT contain a central chiral carbon? a. Glycine b. Tyrosine c. Lysine d. Cysteine e. Threonine 20. Which of the following amino acids is non-polar and non-charged? a. Cysteine b. Tyrosine c. Lysine d. Valine e. Threonine 21. Which of the following elements is not normally found in any of the 20 amino acids? a. carbon b. nitrogen c. sulfur d. phosphorus (phosphate) e. hydrogen 22. Which of the following statements about proteins is/are FALSE? a. They possess peptide bonds between amino acids. b. They can form structural components of the cell. c. They can be enzymes. d. They can be signaling molecules (hormones) such as insulin. e. They can be genetic material. 23. The “C” terminus of a polypeptide is? a. The first amino acid in a polypeptide. b. The last amino acid in a polypeptide. c. An amino acid with a free “R” group. d. An amino acid with a free amino group. e. None of the above are correct. 24. The sequence of amino acids incorporated into a polypeptide is which level of protein structure/folding? a. primary b. Secondary c. tertiary d. quaternary. e. none of the above are correct. 25. The formation of alpha-helices and beta-sheets in proteins is primarily stabilized by? a. ionic bonds b. covalent bonds c. hydrogen bonds d. disulfide bonds e. hydrophobic interactions 26. A type of protein that functions by helping other proteins fold correctly is called a a. foldzyme. b. renaturing protein. c. chaperone protein. d. hemoglobin. e. denaturing protein 27. L-amino acids and D-amino acids differ from each other in what manner? a. they are enantiomers of each other b. L-amino acids are biologically active, D-amino acids are not c. D-amino acids are more hydrophobic than L-amino acids d. answers A and B are correct e. all of the above are correct 28. Which of the following has the molecular formula of C6H12O6? a. an amino acid. b. monosaccharide. c. triglyceride. d. a fatty acid. e. none of the above 29. The difference between α- and β-glucose is a. in the number of covalent bonds present. b. in the arrangement of OH and H atoms attached to the carbon at position 1. c. in the type of R group attached to the terminal carbon. d. that α-glucose is polar, whereas β-glucose is nonpolar. e. that α-glucose is a pentose, whereas β-glucose is a hexose 30. A phospholipid contains which of the following? a. glycerol. b. a polar head group c. 2 fatty acid sides chains d. answers A and B are correct e. all of the above are correct 31. Polyunsaturated triglycerides differ from saturated triglycerides in that they? a. have a lower melting temperature b. have more carbon to carbon double bonds. c. are more often found in animal fats than in plant oils. d. answers A and B are both correct e. all of the above are correct 32. Which statement(s) regarding purines and pyrimidines is/are TRUE? a. Purines only have single bonds in their structure, whereas pyrimidines have both single and double bonds in their structure. b. Pyrimidines are found in RNA only; while purines are found in DNA only. c. Purines consist of hydrogen, carbon, oxygen, and nitrogen, whereas pyrimidines have phosphorus, hydrogen, carbon, oxygen, and nitrogen. d. Purines include the bases of guanine and cytosine; pyrimidines include the bases of adenine and thymine. e. Purine bases are double-ring structures, whereas pyrimidine bases are single-ring structures. 33. Which of the following would NOT be found in DNA? a. ribose. b. phosphate c. Cytosine d. Guanine e. thymine 34. What is attached to the 3´-carbon of deoxyribose in DNA? a. Adenine b. Phosphate c. Hydroxyl d. Thymine e. Hydrogen 35. What is the nucleotide sequence of the complementary strand of the DNA molecule:5’- T T A C G C T-3’? a. 5’-T T A C G C T-3’ b. 3’-A A T G C G A-5’ c. 3’-G G C A T A G-5’ d. 5’-C C G T T A T-3’ e. 3’-A G C G T A A-5’ 36. A guanine/cytosine base paring in DNA is held together with which type of bonds? a. peptide b. van der waals c. hydrogen d. ionic e. glycosidic 37. The central dogma of molecular biology states that a. the information flow in a cell is from DNA to a protein to RNA. b. the information flow between DNA, RNA, and a protein is reversible. c. the information flow in a cell is from DNA to RNA to protein. d. the information flow in a cell is from protein to RNA to DNA. e. the genetic code is ambiguous. 38. All life we can imagine needs? a. oxygen b. water. c. carbon dioxide d. sunlight e. methane 39. Examination of meteorites suggests that a. biological molecules are not limited to Earth. b. early cellular life was commonly obliterated by meteorite impact. c. comets brought Earth most of its water. d. meteorites brought life to Earth. e. meteorites are responsible for Earth’s magnetic field. 40. Which of the following have been demonstrated experimentally? a. RNA-like molecules can self-replicate, elongate, and mutate b. Basic metabolic reactions can occur spontaneously if energy, chemical substrates, and inorganic catalysts are present c. Complex organic molecules can originate from inorganic ones if heat and electricity are applied d. Answers A and B are correct e. All of the above are correct EXAM 1 actual test: 1. The "N" terminus of a polypeptide is? 1.The first amino acid in a polypeptide. The last amino acid in a polypeptide. An amino acid with a free "R" group. An amino acid with a free carboxyl group. None of the above are correct. 2. Glucose and fructose both have the formula C6H1206, but the atoms in these two compounds are arranged differently. Glucose and fructose are therefore? pentoses. 1.structural isomers. Stereosaccharides. isotopes. polysaccharides. 3. The formation of alpha-helices and beta-sheets is which level of protein structure? - Secondary 4. How many molecules of a solute are in 1 liter of a 1M solution? - 6.022 x 10^23 5. Which of the following is correct regarding thymine? - It is one of 4 nitrogenous bases found in DNA. 6. A common health concern in humans is the condition atherosclerosis, in which triglycerides accumulate on the walls of arteries. A diet rich in which of the following is thought to contribute to this condition? - Saturated fat 7. Which of the following functional groups is easily transferred from one molecule to another and is known as the energy currency of living cells? - Phosphate 8. Which of the following amino acids is unique in that it contains an atom of sulfur and forms disulfide bridges in proteins? - Cysteine 9. How would you make 1 liter of an aqueous solution with 1M concentration of a compound that has a molecular weight of 200 daltons [grams]? - Measure out 200 grams of that compound and add water until the volume equals 1000 ml. 10. Carbon-12 is the most abundant isotope of carbon on Earth.Carbon-13 makes up about 1 percent of Earth’s carbon atoms. Which of the following is true? - Carbon-13 has more neutrons than carbon 12. 11. The Miller Urey experiment showed that in an environment with conditions similar to those of primitive Earth, which of the following could occur? - Inorganic molecules could react to form organic molecules. 12. The element oxygen is found in the second row of the periodic table and has an atomic number of 8. How many electrons must oxygen gain in order for its valence shell to be full? - 2. 13. Which of following bond is formed when atoms share electrons equally? - Non-polar covalent 14. The hard shell of insects is made of chitin. Chitin is mostly which of the following? - Carbohydrate 15. Which of the following has a ribose, phosphate and nitrogenous base? - Nucleotide. 16. As a protein folds into its tertiary structure it is potentially stabilized by? - Ionic bonds, 17. In 1969, scientists shaved off pieces of the Murchison meteorite and found both D- and L-isomers of 10 amino acids, as well as purines, pyrimidines, and sugars. This indicates that? - Basic chemical building blocks of life can form extra terrestrially, The meteorite war not contaminated by Earth’s materials, and If appropriate conditions exist [such as temperature and liquid water], cellular life similar to that on earth could form on other planets. 18. Which of the following amino acids is hydrophilic and ionic [charged]? - Lysine 19. The most likely source of Earths atmospheric oxygen was? - Photosynthesis by ancient cyanobacteria [blue-green algae] 20. A type of protein that functions by helping other proteins fold correctly is called a - Chaperone 21. Which of the following elements is found in only 2 of the 20 amino amino acids? - Sulfur 22. What id attached to the 5’ -carbon of deoxyribose in DNA? - Phosphate 23. L-amino acids and D-amino acids differ from each other in what manner? - They are enantiomers of each other 24. The atomic weight or mass of an element is the same as the number of ___ in each atom? - Neutrons plus protons 25. Which of the following statements about living organisms on earth is False? - All living organisms move within their environment - Living organism possess DNA as the genetic material - All living organisms require a source of energy - ALL Living organisms interact with or influence the environment in which they live - Living populations evolve over time 26. Which of the following would not be found in DNA? - Uracil 27. Whats up doc? Eating carrots is considered good for your eyesight as they are rich in the light absorbing molecule vitamin A which is derived from beta-carotene. Beta-carotene is derived from which of the following? - Protein 28. During a condensation reaction in which two amino acids are joined to form a dipeptide, what kind of a bond if formed? - Peptide bond 29. Signaling molecules (hormones) in humans are derived from? - Proteins and lipids 30. Glycogen is an energy storage molecule in human muscle and liver tissue. Glycogen is a ? - Polysaccharide 31. Which of the following is a correct monomer/polymer pairing? - Nucleotide/nucleic acid. 32. Which of the following represents the correct order of the levels of complexity at which life is studied, from most inclusive to least inclusive [most complex to simplest] - Population, organism, organ system, organ, tissue,and cell. 33. After overserving that fish live in clean water but not in polluted water, researchers state that ‘polluted water kills fish’. This statement is an example of a[n]? - Hypothesis 34. Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, the H+ ions are used up as they combine with the bicarbonate anions. When this happens, the pH of the blood? - Does not significantly change. 35. The element Neon is found in the last column of the second row of the periodic table. It’s a noble gas with an atomic number of 10. Which of the following statements about Neon is/are TRUE? - Its 1s electron orbital is full, its 2s electron orbital is full, its 2p orbitals are all full. 36. The tendency of. Atoms to attract electrons is known as? - Electronegativity. 37. Life on Earth arose approximately how many years ago? - 3.5 to 4 billion. 38. Which of the following are special properties of water? - It has a high[large] heat capacity & Its molecules form hydrogen bonds with themselves and solutes. EXAM 1 practice exam: 1. Which represents the correct order of biological organization (from simplest to most complex)? a. cells, molecules, atoms, organ systems, tissues, organism b. molecules, atoms, cells, tissues, organ systems, organism c. organism, organ systems, tissues, cells, molecules, atoms d. atoms, molecules, cells, tissues, organ systems, organism e. atoms, molecules, organ systems, tissues, cells, organism 2. Which of the following is/are features of scientific hypotheses? a. They are based on observations. b. They make predictions. c. They can be tested by experimentation. d. Answers A and B are correct. e. All of the above are correct 3. The part of the atom that carries a positive charge is the a. proton. b. electron. c. neutron. d. innermost shell. e. nucleus. 4. Which of the following elements is NOT common in living things? a. Nitrogen b. Phosphorus c. Flourine d. Carbon e. All of the above 5. The atomic number of an element is the same as the number of _______ in each atom. a. neutrons b. protons c. protons plus electrons d. neutrons plus protons e. neutrons plus electrons 6. Phosphorus has an atomic number of 15 and an atomic weight of 30.974. From this information it can be determined that this element? a. has isotopes. b. usually has 31 neutrons. c. carries a positive charge. d. answers A and B are correct e. all of the above are correct 7. Which of the following is directly involved in forming bonds between atoms? a. the atom’s protons. b. The atom’s nucleus. c. the atom’s neutrons d. valence electrons e. pH. 8. Which of the following is the correct order (in decreasing order) for the relative strengths of chemical bonds? a. van der Waals forces, covalent, ionic, hydrogen b. Ionic, covalent, hydrogen, van der Waals forces c. Covalent, ionic, hydrogen, van der Waals forces d. Hydrogen, covalent, van der Waals forces, ionic e. Ionic, covalent, van der Waals forces, hydrogen 9. The tendency of atoms to attract electrons when it occurs as part of a compound is? a. hydrophobic interactions b. van der waals forces c. electronegativity d. ionic bonds e. radioactivity 10. Ethanol is composed primarily of two carbon atoms and a hydroxyl functional group. Therefore, one would expect ethanol to be? a. hydrophobic. b. hydrophilic. c. a base. d. an acid. e. a buffer. 11. Lithium and fluorine are most likely to form which kind of bond? a. van der Waals interaction b. Hydrogen bond c. Hydrophobic interaction d. Ionic bond e. Covalent bond 12. Which of the following are special properties of water? a. Water has a high (large) heat capacity. b. Water’s solid state is less dense than its liquid state. c. Water molecules form hydrogen bonds between themselves and with solutes. d. Answers A and B are correct e. All of the above are correct 13. Which contains more molecules, a mole of glucose or a mole of fructose? a. a mole of glucose b. a mole of fructose c. both contain the same number of molecules. d. inadequate information is provided. e. it depends on the pH of the system. 14. To determine the number of molecules in a teaspoon of sugar you have to know a. Avogadros number (6.022 x 1023 molecules/mole). b. the weight of the sugar. c. the molecular weight of the sugar. d. answers A and B are correct e. all of the above are correct 15. How would you make 1 liter of an aqueous solution with a 0.50 M concentration of a compound that has a molecular weight of 200 daltons (grams)? a. Add 0.50 grams of the compound to 1000 ml of water. b. Add 500 grams of the compound to 1000 ml of water. c. Measure out 100 grams of the compound and add water until the volume equals 1000 ml. d. Measure out 50 grams of the compound and add water until the volume equals 1000 ml. e. Measure out 5 grams of the compound and add water until the volume equals 1000 ml. 16. Two samples of rainwater have H+ concentrations of 10–4 mol/L (Sample A) and 10–6 mol/L (sample B) respectively. Which of the following statements is/are FALSE? a. the pH of Sample A is 4 b. the pH of Sample B is 6 c. Sample A is more acidic than Sample B d. Sample A is more basic than Sample B e. Sample A has 100 times more H+ in solution than Sample B 17. Carbonic acid and sodium bicarbonate act as buffers in the blood. When a small amount of acid is added to this buffer, the H+ ions are used up as they combine with the bicarbonate ions. When this happens, the bicarbonate ion is described as a? a. weak (conjugate) basic. b. weak (conjugate) acid. c. hydrogen chelator d. cation e. all of the above are correct 18. When hydrochloric acid (HCL) is added to water, it ionizes, releasing Cl– and H+ ions. The resulting solution is a. acidic. b. basic. c. anionic. d. molar. e. a buffer. 19. Which of the following functional groups is frequently transferred from one molecule to another and is considered the “energy currency” of living cells? a. carboxyl b. amino. c. hydroxyl. d. phosphate. e. ketone. 20. Molecules containing a large number of amino groups are? a. basic. b. acidic. c. involved in reactions forming more simple molecules. d. nonpolar and non-charged. e. highly insoluble in water. 21. Which of the following is a correct monomer/polymer pairing? a. Monosaccharide/triglyceride b. Amino acid/protein c. Triglyceride/cellulose d. Nucleotide/polysaccharide e. Monosaccharide/protein 22. During the formation of a peptide linkage, a(n) _______ is formed. a. molecule of water b. covalent bond c. disulfide bond d. answers A and B are correct e. all of above are correct 23. Enzymes are usually a. DNA. b. lipids. c. proteins. d. carbohydrates. e. amino acids. 24. Which of the following amino acid(s) would be described as non-polar and hydrophobic? a. Leucine b. Aspartic acid c. Serine d. Arginine e. Tyrosine 25. Which of the following amino acid(s) would be described as electrically charged (ionic)? a. Leucine b. Arginine c. Methionine d. Cysteine e. Threonine 26. Which of the following is NOT found in every amino acid? a. carbon b. nitrogen c. sulfur d. oxygen e. hydrogen 27. Which of the following general statements about proteins is FALSE? a. Some function as enzymes. b. The can form structural components of the cell. c. They possess peptide linkages between amino acids. d. They are highly insoluble in water. e. They are necessary for immune function in humans (antibodies). 28. The amino acid Cysteine may be involved in what unique bond? a. peptide bond b. disulfide bond c. hydrophobic interactions d. glycosidic bond e. phosphodiester bond 29. The “C” terminus of a polypeptide is? a. the first amino acid b. the last amino acid c. an amino acid with a free amino group d. an amino acid with a free carboxyl group e. answers B and D are both correct 30. The tertiary shape of a folded protein is influenced by a. the sequence of its amino acids. b. hydrogen bonds c. hydrophobic interactions d. ionic interactions between R-groups. e. all of the above are correct. 31. The amino acids of the protein keratin are arranged in a helix. This secondary structure is stabilized primarily by a. covalent bonds. b. peptide bonds. c. glycosidic linkages. d. hydrogen bonds. e. polar bonds. 32. The protein hemoglobin has four separate polypeptide subunits and a heme group. This level of protein structure (or folding) is known as? a. primary. b. secondary. c. tertiary d. quaternary e. none of the above are correct 33. Which of the following levels of protein structure is stabilized entirely by covalent bonds? a. Primary b. Secondary c. Tertiary d. Quaternary e. none of the above 34. Which of the following environmental factors influences protein folding a. pH b. temperature c. molecular chaperones d. concentrations of other polar molecules. e. all of the above e 39. [Show Less]