Human Biology: Concepts And Current Issues, 8th Edition Test Bank

Human Biology: Concepts and Current Issues, 8e (Johnson) Chapter 2 The Chemistry of Living Things 2.1 Multiple-Choice Questions 1) Which one of the following is the study of matter and the energy that causes matter to combine, break apart, and recombine in everything living and nonliving? A) biology B) geology C) chemistry D) physics Answer: C Topic: Sec. 2.0 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 2) Which one of the following characteristics applies to both living organisms and nonliving things? A) composed of matter B) capable of reproduction C) capable of storing energy for later use D) capable of growth E) composed of cells Answer: A Topic: Sec. 2.0 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 3) A mad scientist has ripped apart an atom and collected all the subatomic particles located in the nucleus of the atom. Which one of the following has he collected? A) electrons B) protons C) protons and neutrons D) electrons and protons E) neutrons and electrons Answer: C Topic: Sec. 2.1 Bloom’s: Applying/Analyzing LO: 2.1 GLO: G2 1 Copyright © 2017 Pearson Education, Inc. 4) Which one of the following statements is TRUE regarding the structure of the atom? A) The nucleus is composed of equal numbers of positively charged particles and negatively charged particles. B) All electrons are located at the same distance from the nucleus. C) In small elements, such as carbon, electrons have a positive charge; in larger elements, such as barium, electrons have a negative charge. D) Most of the mass of an atom is due to its protons and neutrons. E) Neutrons carry a negative charge. Answer: D Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 5) Which one of the following statements CORRECTLY describes the relationship between an atom and an element? A) An element is the fundamental unit of an atom. B) An element is composed of atoms that are joined together by ionic and covalent bonds. C) An atom is composed of different elements that are joined together by ionic and covalent bonds. D) An atom is the smallest unit of an element that demonstrates all of the properties of that element. Answer: D Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 6) The total number of protons and neutrons in an atom can best be determined by A) atomic mass. B) the subscript number following the chemical symbol. C) the atomic number. D) the charge of the atom. E) the chemical symbol. Answer: A Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 2 Copyright © 2017 Pearson Education, Inc. 7) Isotopes of an element have the same ________, but different ________. A) number of electron shells; numbers of protons B) atomic number; atomic masses C) number of neutrons; numbers of protons D) atomic mass; atomic numbers E) name; chemical symbols Answer: B Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 8) Radioisotopes have a number of uses in science and medicine. These uses include which one of the following? A) repairing damaged heart tissue B) dating fossils and treating cancer C) providing the power supply in heart pacemakers D) treating asthma and regulating nerve transmission E) curing diabetes Answer: B Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 9) Chlorine has an atomic number of 17 and an atomic mass of 35. Therefore, chlorine has ________ electrons and ________ neutrons. A) 17; 18 B) 18; 17 C) 17; 35 D) 35; 17 E) 18; 18 Answer: A Topic: Sec. 2.1 Bloom’s: Applying/Analyzing LO: 2.1 GLO: G1 3 Copyright © 2017 Pearson Education, Inc. 10) Which one of the following is TRUE regarding electrons, shells, and energy? A) Electrons are located in shells around the nucleus. B) Electrons are attracted to each other because they have the same charge. C) In order for an electron to move closer to the nucleus, it must absorb energy. D) The innermost electron shell has the most potential energy. E) As an electron moves to a shell further from the nucleus, it loses energy. Answer: A Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 11) Which one of the following is a molecule? A) NaCl B) O C) C D) Lead E) N Answer: A Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G2 12) An example of potential energy is/are A) bonds that hold atoms together. B) energy for creating new molecules. C) dancing. D) running a marathon. Answer: A Topic: Sec. 2.2 Bloom’s: Applying/Analyzing LO: 2.2 GLO: G2 13) ________ bonds hold the hydrogens to the oxygen within a water molecule, and ________ bonds attract one water molecule to other water molecules. A) Ionic; hydrogen B) Hydrogen; ionic C) Hydrogen; covalent D) Covalent; hydrogen E) Ionic; covalent Answer: C Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 4 Copyright © 2017 Pearson Education, Inc. 14) Ions in body fluids of a human are referred to as A) electrolytes. B) osmolytes. C) isotopes. D) atoms. Answer: A Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 15) Which one of the following is TRUE regarding water? A) Each molecule of water consists of two atoms of hydrogen and one atom of oxygen covalently bonded to each other. B) The oxygen side of the water molecule is partially positive. C) Water is a type of ion. D) Electrons are shared equally between the atoms of water. E) Water molecules are attracted to each other by ionic bonds. Answer: A Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 16) Each of the following statements is TRUE regarding hydrogen bonds EXCEPT which one? A) Hydrogen bonds hold the two strands of DNA together. B) Hydrogen bonds are responsible for the attraction of Na+ to Cl-. C) Hydrogen bonds are responsible for some aspects of the three-dimensional structure of proteins. D) Hydrogen bonds form between different water molecules. Answer: B Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G2 5 Copyright © 2017 Pearson Education, Inc. 17) Molecules such as water are referred to as ________ because they are electrically neutral overall but still have partially charged regions. A) electrolytes B) polar molecules C) ions D) covalently charged E) isotopes Answer: B Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 18) Water is an excellent solvent for biological systems because A) it can maintain a relatively unstable temperature for chemical reactions to occur. B) compounds with ionic bonds as well as those with polar covalent bonds readily dissolve in water. C) it is semisolid at body temperature, preventing it from flowing freely through the human body. D) it can rearrange its bonds, forming covalent bonds with other molecules once dissolved. Answer: B Topic: Sec. 2.3 Bloom’s: Remembering/Understanding LO: 2.3 GLO: G1 19) A solution has been prepared by mixing glucose in water. Which one of the following statements CORRECTLY describes this solution? A) Both water and glucose are solutes. B) Both water and glucose are solvents. C) Water is the solute, and glucose is the solvent. D) Water is the solvent, and glucose is the solute. Answer: D Topic: Sec. 2.3 Bloom’s: Applying/Analyzing LO: 2.3 GLO: G2 6 Copyright © 2017 Pearson Education, Inc. 20) A solution with a pH of 6 has ________ times as many hydrogen ions as a solution with a pH of 8. A) 1,000 B) 10 C) 100 D) 10,000 E) 100,000 Answer: C Topic: Sec. 2.4 Bloom’s: Applying/Analyzing LO: 2.4 GLO: G4 21) A student measuring the pH of the water in a fish tank found it to have a pH of 8. Which one of the following statements is TRUE regarding that solution? A) The water is alkaline. B) The water does not contain hydrogen ions. C) The water contains equal numbers of hydrogen ions and hydroxyl ions. D) The water is highly acidic. E) The water is more alkaline than a solution with a pH of 10. Answer: A Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G2 22) Body fluids in humans have a high buffering capacity because of A) the presence of the bicarbonate/carbonic acid buffer system. B) the natural result of water as a solvent. C) hydrogen bonding between water molecules in biological fluids. D) shifts in blood pH that are required to maintain homeostasis. Answer: A Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G1 7 Copyright © 2017 Pearson Education, Inc. 23) Each of the following statements about carbon is TRUE EXCEPT which one? A) All organic molecules contain carbon. B) Carbon atoms form four covalent bonds. C) Carbon atoms form diverse molecules that may be linear, branched, or circular. D) Carbon can form strong hydrogen bonds with other elements. E) Carbon can form bonds with hydrogen, oxygen, nitrogen, as well as another carbon atom. Answer: D Topic: Sec. 2.5 Bloom’s: Remembering/Understanding LO: 2.5 GLO: G2 24) Which one of the following is TRUE regarding macromolecules? A) Cells cannot use macromolecules to signal other cells. B) An example of a macromolecule is H2O. C) Cells produce macromolecules by the process of hydrolysis. D) Macromolecules are broken down by hydration synthesis. E) Cells use certain macromolecules to store energy. Answer: E Topic: Sec. 2.5 Bloom’s: Remembering/Understanding LO: 2.5 GLO: G1 25) Which one of the following statements accurately describes hydrolysis reactions in biological systems? A) Hydrolysis reactions enable the breakdown of food molecules during digestion. B) Hydrolysis reactions enable small molecules to be joined to form larger molecules. C) Hydrolysis reactions generally require substantial input of energy. D) Hydrolysis reactions are spontaneous and don’t require catalysis by enzymes. E) Hydrolysis reactions generally occur for the purpose of energy storage. Answer: A Topic: Sec. 2.5 Bloom’s: Remembering/Understanding LO: 2.5 GLO: G1 8 Copyright © 2017 Pearson Education, Inc. 26) Carbohydrates have which one of the following characteristics? A) They are composed of carbon, hydrogen, nitrogen, and oxygen. B) They release energy when their peptide bonds are broken. C) They are indigestible by most organisms. D) They contain carbon, hydrogen, and oxygen in a ratio of 1-2-1. E) They are able to store and transmit genetic information. Answer: D Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 27) Which one of the following is a very important source of energy for nearly all cells? A) cellulose B) deoxyribose C) starch D) glucose E) ribose Answer: D Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 28) Lactose is a(n) A) ribose. B) monosaccharide. C) oligosaccharide. D) polysaccharide. E) starch. Answer: C Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 29) Sucrose is an oligosaccharide made up of which one of the following sugars? A) glucose and glucose B) deoxyribose and ribose C) starch and glycogen D) maltose and glucose E) glucose and fructose Answer: E Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 9 Copyright © 2017 Pearson Education, Inc. 30) Lipids are important to biological systems because A) they are solid at body temperature so they stabilize membranes. B) some lipid types are potentially large sources of energy to perform cellular work. C) most help to buffer aqueous solutions in the body. D) all lipids are very soluble in water. E) they are able to store and transmit genetic information. Answer: B Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 31) Which one of the following molecules is stored in adipose tissue and serves as an important source of energy for the human body? A) glucose B) steroids C) glycogen D) triglycerides E) phospholipids Answer: D Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 32) Which one of the following is a lipid? A) cholesterol B) alanine C) maltose D) glycogen E) cellulose Answer: A Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 10 Copyright © 2017 Pearson Education, Inc. 33) The most important physical characteristic of lipids with regard to living organisms is that they A) are hydrophobic. B) are very large and therefore difficult to store. C) dissolve easily in water. D) are typically a form of waste product that is difficult to eliminate. E) are denser than water. Answer: A Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 34) Which one of the following forms a bilayer structure that is found in cell membranes? A) triglycerides B) amino acids C) cholesterol D) phospholipids E) saturated fats Answer: D Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 35) Pancreatic cells make insulin, which is a type of protein. These cells use ________ in order to synthesize insulin by the process of ________. A) oligosaccharides; hydrolysis B) nucleotides; condensation C) amino acids; dehydration synthesis D) fatty acids and glycerol; hydrolysis E) monosaccharides; dehydration synthesis Answer: C Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G2 11 Copyright © 2017 Pearson Education, Inc. 36) Each amino acid is composed of a central carbon that forms covalent bonds with four other atoms/molecules. These atoms/molecules include each of the following EXCEPT which one? A) an R group B) an A group C) an amino group D) a hydrogen atom E) a carboxyl group Answer: B Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 37) Alpha helices and beta sheets are characteristic of protein A) primary structure. B) secondary structure. C) tertiary structure. D) quaternary structure. E) enzymatic structure. Answer: B Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 38) Which one of the following is a function of a protein? A) stores genetic material and enables its transmission to the next generation B) acts as a catalyst, speeding up chemical reactions C) is a major subunit of cellulose D) is a primary structural component of a cell membrane E) provides energy for a muscle contraction Answer: B Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 12 Copyright © 2017 Pearson Education, Inc. 39) Which one of the following is TRUE regarding enzymes? A) Enzyme function is not affected by changes in temperature or pH. B) Enzymes slow the rate of chemical reactions in living systems. C) Enzymes are consumed in a chemical reaction, so an organism must constantly replace these enzymes. D) Each enzyme catalyzes one specific reaction or group of reactions. E) Enzymes convert products into reactants. Answer: D Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 40) Proteins that function as a catalyst A) slow down the speed at which chemical reactions occur but do not alter the final products formed. B) facilitate chemical reactions by altering the final products formed. C) maintain primary structure. D) can participate only in reactions that synthesize new products. E) are referred to as enzymes. Answer: E Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 41) Which one of the following is needed to synthesize a new strand of DNA? A) lipids B) glucose C) amino acids D) nucleotides E) ribose Answer: D Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 13 Copyright © 2017 Pearson Education, Inc. 42) DNA differs from RNA in that DNA A) is single stranded. B) contains deoxyribose. C) is made up of nucleotides. D) contains cytosine. E) contains phosphates. Answer: B Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 43) A research student is analyzing the nucleic acid of a virus. He finds that the nucleic acid contains thymine. From this it can be concluded that the nucleic acid A) contains uracil. B) contains ribose. C) is actually a protein. D) contains glucose. E) is a strand of DNA. Answer: E Topic: Sec. 2.9 Bloom’s: Applying/Analyzing LO: 2.9 GLO: G2 44) Which one of the following is TRUE regarding nucleotides? A) There are three different DNA nucleotides. B) DNA nucleotides are assembled into RNA by the process of dehydration synthesis. C) DNA nucleotides contain deoxyribose; RNA nucleotides contain sucrose. D) Nucleotides are bonded together by covalent bonds between the sugars and the phosphates. E) A DNA nucleotide could be made up of ribose, a phosphate, and cytosine. Answer: D Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 14 Copyright © 2017 Pearson Education, Inc. 45) Which one of the following occurs when a phosphate is removed from an ATP molecule? A) Energy is added to the ATP molecule to form ADP. B) Oxygen produced in the reaction causes the molecule to explode. C) Energy is released for cell work. D) Chemical reactions stop in a cell due to lack of an energy source. E) Fat is converted to protein. Answer: C Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G2 46) A student has isolated a large compound (macromolecule) from cells. Chemical analysis of the compound shows that it is made up of the following elements: carbon, hydrogen, oxygen, nitrogen, and sulfur. To which group of macromolecules does this compound most likely belong? A) carbohydrate B) protein C) nucleic acid D) lipid E) aqueous Answer: B Topic: Sec. 2.6, 2.7, 2.8, 2.9 Bloom’s: Applying/Analyzing LO: 2.6-2.9 GLO: G7 47) A student has isolated a large compound (macromolecule) from cells. Chemical analysis of the compound shows that it is made up of the following elements: carbon, hydrogen, oxygen, nitrogen, and phosphorus. To which group of macromolecules does this compound most likely belong? A) carbohydrate B) protein C) nucleic acid D) lipid E) aqueous Answer: C Topic: Sec. 2.6, 2.7, 2.8, 2.9 Bloom’s: Applying/Analyzing LO: 2.6-2.9 GLO: G7 15 Copyright © 2017 Pearson Education, Inc. 2.2 True/False Questions 1) Electrons are smaller than protons, are negatively charged, and orbit the nucleus. Answer: TRUE Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 2) All matter is made up of atoms. Answer: TRUE Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 3) If the number of protons in an atom equals the number of electrons in the atom, the atom is an ion. Answer: FALSE Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 4) Atoms with either more or fewer neutrons than the usual number for an element are referred to as isotopes. Answer: TRUE Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 5) Lipids stored in the body are an example of potential energy. Answer: TRUE Topic: Sec. 2.2, 2.7 Bloom’s: Applying/Analyzing LO: 2.2, 2.7 GLO: G1 6) When water is released from a dam, potential energy is converted to chemical energy. Answer: FALSE Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 16 Copyright © 2017 Pearson Education, Inc. 7) The type of bond indicated by the dotted lines in the accompanying figure is a hydrogen bond. Answer: TRUE Topic: Sec. 2.3 Bloom’s: Remembering/Understanding LO: 2.3 GLO: G1 8) The difference between water molecules in liquid water and water molecules in ice is in the number of covalent bonds that form. Answer: FALSE Topic: Sec. 2.3 Bloom’s: Remembering/Understanding LO: 2.3 GLO: G1 9) During intense exercise, you produce a lot of heat energy, yet your body temperature rises only in small increments. This temperature stability is because water in body fluids releases the heat very quickly. Answer: FALSE Topic: Sec. 2.3 Bloom’s: Remembering/Understanding LO: 2.3 GLO: G1 10) One of the most important buffer pairs in blood is carbonic acid and bicarbonate because they regulate the pH of blood by absorbing and releasing hydrogen ions as needed. Answer: TRUE Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G1 17 Copyright © 2017 Pearson Education, Inc. 11) The more buffers present in a body fluid, the more likely that the blood pH will change after absorbing nutrients during digestion. Answer: FALSE Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G2 12) Because carbon requires four additional electrons to fill its outermost shell, it has a natural tendency to form four covalent bonds with other atoms, making it an ideal element for forming structures in living cells. Answer: TRUE Topic: Sec. 2.5 Bloom’s: Remembering/Understanding LO: 2.5 GLO: G1 18 Copyright © 2017 Pearson Education, Inc. 13) The accompanying figure shows a triglyceride that contains unsaturated fatty acids. Answer: FALSE Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 19 Copyright © 2017 Pearson Education, Inc. 14) The accompanying figure shows a triglyceride that is liquid at room temperature. Answer: TRUE Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 15) If your blood pH is lowered significantly, many proteins will not be able to fold correctly. The result will be decreased enzyme function throughout the body. Answer: TRUE Topic: Sec. 2.8 Bloom’s: Applying/Analyzing LO: 2.8 GLO: G2, G7 20 Copyright © 2017 Pearson Education, Inc. 2.3 Matching Questions Match each of the following descriptions to the appropriate term. Each term may be used only once. A) proton B) nucleic acids C) carbohydrates D) lipids E) isotopes F) electrons G) amino acids H) atom I) chemical bonds J) matter K) molecules L) elements 1) a component of an atom that carries a positive charge Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 2) the smallest unit of matter that can take part in a chemical reaction Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 3) anything that has mass and occupies space Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 4) attractive forces between atoms in molecules Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 5) different forms of the same element that differ in their number of neutrons Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 21 Copyright © 2017 Pearson Education, Inc. 6) steroids, triglycerides Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 7) matter that cannot be broken down Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 8) DNA, RNA Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 9) water, sodium chloride, carbon dioxide Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G2 10) alanine, glycine, cysteine Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 11) glucose, cellulose, glycogen Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 12) part of an atom that may participate in bonding with another atom Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 Answers: 1) A 2) H 3) J 4) I 5) E 6) D 7) L 8) B 9) K 10) G 11) C 12) F 22 Copyright © 2017 Pearson Education, Inc. Match the following. A) cholesterol B) unsaturated fat C) cellulose D) polypeptide E) glucose F) saturated fat G) DNA H) glycogen 13) a double strand of nucleotides; stores genetic information Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 14) lipid that stabilizes membranes and is a precursor to many hormones Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 15) dominant energy source used by cells Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 16) major structural polysaccharide produced by plants Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 17) a molecule consisting of glycerol plus fatty acid chains with two hydrogen atoms per carbon atom; solid at room temperature Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 18) a polysaccharide stored in the human body Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 23 Copyright © 2017 Pearson Education, Inc. 19) a strand of 3 to 100 amino acids Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 20) a triglyceride that has double bonds in its fatty acids and is a liquid at room temperature Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 Answers: 13) G 14) A 15) E 16) C 17) F 18) H 19) D 20) B 24 Copyright © 2017 Pearson Education, Inc. 2.4 Short Answer Questions Use the letters from the accompanying figure to answer the following questions. 1) The subatomic particles ________ and ________ have approximately the same mass. Answer: B; C Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 2) Isotopes of this element would differ in the number of ________. Answer: B Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 3) In order for this atom to be electrically neutral, the number of subatomic particles labeled “A” in the figure would have to equal the number of ________. Answer: C Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 4) The label ________ points to a neutron. Answer: B Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 25 Copyright © 2017 Pearson Education, Inc. 5) In order for this atom to develop a positive charge, it would have to lose ________. Answer: A Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 6) The number of subatomic particles ________ is the atomic number of that atom. Answer: C Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 7) All things on Earth are made up of ________, which is defined as anything that has mass and occupies space. Answer: matter Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 8) The pure form of matter that cannot be broken down into a simpler form is a(n) ________. Answer: element Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 9) Protons and neutrons are located in the ________ of an atom. Answer: nucleus Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 10) The outermost electron ________ of an atom can interact with other atoms to form a molecule. Answer: shell Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 26 Copyright © 2017 Pearson Education, Inc. 11) Isotopes that give off energy and emit particles are known as ________. Answer: radioisotopes Topic: Sec. 2.1 Bloom’s: Remembering/Understanding LO: 2.1 GLO: G1 12) Water held behind a dam has a large amount of ________ energy. Answer: potential Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 13) An electrically charged molecule or atom is a(n) ________. Answer: ion Topic: Sec. 2.2 Bloom’s: Remembering/Understanding LO: 2.2 GLO: G1 14) Molecules that are polar and attracted to water are ________; molecules that are nonpolar and therefore not attracted to water are ________. Answer: hydrophilic; hydrophobic Topic: Sec. 2.3 Bloom’s: Remembering/Understanding LO: 2.3 GLO: G1 15) Water can ________ heat to help prevent rapid body temperature changes. Answer: absorb Topic: Sec. 2.3 Bloom’s: Applying/Analyzing LO: 2.2 GLO: G2 16) Molecules that give up or donate hydrogen ions are ________. Answer: acids Topic: Sec. 2.3 Bloom’s: Remembering/Understanding LO: 2.3 GLO: G1 27 Copyright © 2017 Pearson Education, Inc. 17) The acidity or alkalinity of a solution can be measured in terms of ________. Answer: pH Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G1 18) Which solution has more free hydrogen ions: pH = 9 or pH = 3? Answer: pH = 3 Topic: Sec. 2.4 Bloom’s: Applying/Analyzing LO: 2.4 GLO: G1 19) The pH of human blood falls within a ________ range that is near a pH of 7.4. Answer: neutral Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G1 20) A substance that helps to maintain a stable pH is a(n) ________. Answer: buffer Topic: Sec. 2.4 Bloom’s: Remembering/Understanding LO: 2.4 GLO: G1 21) Living organisms covalently link smaller molecules to synthesize large organic molecules called ________. Answer: macromolecules Topic: Sec. 2.5 Bloom’s: Remembering/Understanding LO: 2.5 GLO: G1 22) The process by which cells break down organic macromolecules into their subunits is ________. Answer: hydrolysis Topic: Sec. 2.5 Bloom’s: Remembering/Understanding LO: 2.5 GLO: G1 28 Copyright © 2017 Pearson Education, Inc. 23) Plants produce a polysaccharide made of glucose known as ________, which is virtually indigestible by most animals. Answer: cellulose Topic: Sec. 2.6 Bloom’s: Remembering/Understanding LO: 2.6 GLO: G1 24) In order for a cell to produce a fat, it must have one molecule of ________ and three ________. Answer: glycerol; fatty acids Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 25) A diet rich in ________ fat is believed to contribute to the development of cardiovascular disease. Answer: saturated Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 26) The structure of a cell membrane includes a modified form of lipid called a(n) ________. Answer: phospholipid Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 27) Lipid molecules composed of four joined carbon rings, such as cholesterol, are known as ________. Answer: steroids Topic: Sec. 2.7 Bloom’s: Remembering/Understanding LO: 2.7 GLO: G1 28) When a protein is heated, it may unfold, losing its secondary, tertiary, and even quaternary structure. This process is known as ________. Answer: denaturation Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 29 Copyright © 2017 Pearson Education, Inc. 29) A polypeptide is generally referred to as a(n) ________ if it has more than 100 amino acids and has folded into a complex structure with a specific function. Answer: protein Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 30) The molecule that an enzyme reacts with is a ________. Answer: substrate (reactant) Topic: Sec. 2.8 Bloom’s: Remembering/Understanding LO: 2.8 GLO: G1 31) The molecule that stores the set of instructions of a cell and directs everything a cell does is ________. Answer: DNA Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 32) The four nucleotides that make up DNA contain a sugar component called ________. Answer: deoxyribose Topic: Sec. 2.9 Bloom’s: Remembering/Understanding LO: 2.9 GLO: G1 33) The universal energy source for cells is a nucleotide known as ________. Answer: ATP Topic: Sec. 2.10 Bloom’s: Remembering/Understanding LO: 2.10 GLO: G1 30 Copyright © 2017 Pearson Education, Inc. 2.5 Essay Questions 1) Explain how water in the human body helps to regulate body temperature following a longdistance bike ride. Answer: Water in body fluids is able to absorb heat without experiencing large temperature shifts. Water is also able to hold the heat, so that when the warm fluid moves to the periphery of the body, the heat can be exchanged or released into the environment. Perspiration is one means for the heat to be released from the body, which in turn allows a person to maintain a relatively constant body temperature. Topic: Sec. 2.3 Bloom’s: Applying/Analyzing LO: 2.3 GLO: G5, G8 2) In the human body, bicarbonate and carbonate ions work together to stabilize or buffer the pH of body fluids. What would happen to blood if these buffering agents were removed? Answer: Blood pH could not be regulated in the absence of this buffering pair. Anything absorbed or released from body fluids that altered the hydrogen or hydroxyl ion content of blood would cause a pH change. For humans who tightly regulate homeostasis, even relatively modest changes in blood pH can have devastating consequences. Topic: Sec. 2.4 Bloom’s: Applying/Analyzing LO: 2.4 GLO: G5, G8 3) Describe how denaturing a protein alters the function of that protein. Answer: Denaturing a protein permanently disrupts protein structure. Ordinarily, if the protein shape is altered, so is the function of that protein. This can be seen with denatured enzymes that lose the ability to bind the substrate, and thus no chemical reaction can occur. Topic: Sec. 2.8 Bloom’s: Applying/Analyzing LO: 2.8 GLO: G7, G8 31 Copyright © 2017 Pearson Education, Inc.