Download Biochemistry 60 questions

Biochemistry 60 Questions
Name___________________________________
MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.
1) The four most common elements in living organisms are
A) C, H, O, Fe.
B) C, N, O, Na.
C) C, H, O, Na.
D) C, H, O, N.
1)
2) Which of the following statements regarding matter is false?
A) All life is composed of matter.
B) All matter is composed of elements.
C) All matter has mass.
D) All matter exists in the form of compounds.
2)
3) Which of the following statements best describes a compound?
A) A compound is a pure element.
B) A compound contains two or more different elements in a fixed ratio.
C) A compound is a solution.
D) A compound is exemplified by sodium.
3)
4) In the equation 2 H2 + O2
4)
2 H2 O,
A) only H2O is a compound.
B) only H2 and O2 are compounds.
C) H2 , O2 , and H2O are all compounds.
D) H2 , O2 , and H2O are all elements.
5) Which of the following particles is found in the nucleus of an atom?
A) protons and electrons
B) protons and neutrons
C) only protons
D) only electrons
5)
6) What is the atomic mass of an atom that has 6 protons, 6 neutrons, and 6 electrons?
A) 12
B) 8
C) 6
D) 18
6)
7) An uncharged atom of boron has an atomic number of 5 and an atomic mass of 11. How many
electrons does boron have?
A) 5
B) 15
C) 11
D) 2
7)
8) Which of the following is another term used for atomic mass?
A) calvin
B) dalton
C) mendel
8)
9) Which of the following best describes the atomic number of an atom?
A) the number of neutrons in the atom
B) the number of protons in the atom
C) the number of electrons in the atom
D) the number of protons, electrons, and neutrons in the atom
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D) darwin
9)
10) Typically, nitrogen atoms are composed of electrons, protons, and neutrons. An isotope of nitrogen
could
A) have more protons than the usual nitrogen atom.
B) have more neutrons than the usual nitrogen atom.
C) be positively charged.
D) be negatively charged.
10)
11) A radioactive isotope is an isotope that
A) has the same atomic mass, but a different atomic number than the common variant of the
element.
B) decays.
C) has more protons than the common variant of the element.
D) is stable.
11)
12) When full, the innermost electron shell of argon contains ________ electrons, and the outermost
shell contains ________ electrons.
A) 2 . . . 8
B) 4 . . . 8
C) 2 . . . 2
D) 8 . . . 8
12)
13) A(n) ________ forms when two atoms share electrons.
A) ionic bond
B) ion
C) hydrogen bond
13)
D) covalent bond
14) A hydrogen atom has one electron. How many covalent bonds can hydrogen form?
A) two covalent bonds
B) no covalent bonds
C) four covalent bonds
D) one covalent bond
14)
15) What is the fundamental difference between covalent and ionic bonding?
A) In covalent bonding, both partners end up with filled outer electron shells; in ionic bonding,
one partner does and the other does not.
B) Covalent bonding involves only the outermost electron shell; ionic bonding also involves the
next electron shell inside the outermost shell.
C) In a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts
electrons from the other.
D) Covalent bonds form between atoms of the same element; ionic bonds form between atoms of
different elements.
15)
16) Which of the following statements regarding the oxygen atom of a water molecule is true?
A) Oxygen is attracted to the negatively charged atoms of other molecules.
B) Oxygen is more positively charged than the hydrogen atoms.
C) Oxygen attracts electrons less strongly than the hydrogen atoms.
D) Oxygen is more electronegative than the hydrogen atoms.
16)
17) ________ are weak bonds that are not strong enough to hold atoms together to form molecules but
are strong enough to form bonds within and around large molecules.
A) Polar covalent bonds
B) Hydrogen bonds
C) Covalent bonds
D) Ionic bonds
17)
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18) Water molecules stick to other water molecules because
A) the oxygen atoms of adjacent water molecules are attracted to one another.
B) hydrogen bonds form between the hydrogen atoms of one water molecule and the oxygen
atoms of other water molecules.
C) covalent bonds form between the hydrogen atoms of one water molecule and the oxygen
atoms of other water molecules.
D) water molecules are neutral, and neutral molecules are attracted to each other.
18)
19) In the equation 2 H2 + O2
19)
________.
A) reactants . . . products
C) used . . . stored
2 H2 O, the H2 molecules are ________ and the H2 O molecules are
B) products . . . reactants
D) created . . . destroyed
20) The tendency of water molecules to stick together is referred to as
A) transpiration.
B) polarity.
C) adhesion.
D) cohesion.
20)
21) Which of the following statements regarding carbon is false?
A) Carbon has the ability to bond together to form extensive, branched, or unbranched "carbon
skeletons."
B) Carbon has a tendency to form covalent bonds.
C) Carbon has the capacity to form single and double bonds.
D) Carbon has the ability to bond with up to six other atoms.
21)
22) Propanol and isopropanol are isomers. This means that they have
A) different molecular formulas, but the same chemical properties.
B) the same molecular formula, but different chemical properties.
C) the same molecular formula and the same chemical properties.
D) the same molecular formula, but represent different states of the compound.
22)
23) Which of the following statements about the functional groups of organic compounds is false?
A) Functional groups help make organic compounds hydrophilic.
B) Functional groups participate in chemical reactions.
C) All functional groups include a carbon atom.
D) Many biological molecules have two or more functional groups.
23)
24) Which of the following functional groups is capable of regulating gene expression?
A) COOH
B) CO
C) CH3
D)
24)
25) A molecule with the formula C55H110O55 is probably a(n)
A) protein.
B) polysaccharide.
C) steroid.
OH
25)
D) oil.
26) A disaccharide forms when
A) two monosaccharides join by dehydration synthesis.
B) two starches join by hydrolysis.
C) two starches join by dehydration synthesis.
D) two monosaccharides join by hydrolysis.
26)
27) High-fructose corn syrup is made from corn. The main carbohydrate in corn is a polysaccharide
called
A) starch.
B) fructose.
C) cellulose.
D) hydrocarbon.
27)
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28) Which of the following lists contains only polysaccharides?
A) fructose, cellulose, and glucose
B) starch, amino acids, and glycogen
C) sucrose, starch, and cellulose
D) cellulose, starch, and glycogen
28)
29) Foods that are high in fiber are most likely derived from
A) red meats.
B) dairy products.
C) plants.
29)
D) fish.
30) Which of the following organisms contain the polysaccharide chitin?
A) plants and bacteria
B) insects and plants
C) fungi and insects
D) animals and plants
30)
31) An oil may be converted into a substance that is solid at room temperature by
A) adding hydrogens, decreasing the number of double bonds in the molecules.
B) removing water, causing a dehydration synthesis reaction to occur.
C) cooling it, so that double bonds form and the fats solidify.
D) removing hydrogens, increasing the number of double bonds.
31)
32) A diet high in animal products and hydrogenated vegetable margarine may increase the risk for
atherosclerosis. This is because
A) most animal fats are unsaturated and most hydrogenated vegetable margarines contain high
levels of steroids.
B) most animal fats are saturated and many hydrogenated vegetable margarines contain high
levels of trans fats.
C) most hydrogenated vegetable margarines are hydrogenated oils and most animal products
contain high levels of phospholipids.
D) most animal fats are used for energy storage and most hydrogenated vegetable margarines
contain high levels of unsaturated fats.
32)
33) What feature of fats makes them hydrophobic?
A) Fats have carboxyl groups.
C) Fats include one glycerol molecule.
33)
B) Fats have nonpolar hydrocarbon chains.
D) Fats have polar fatty acids.
34) Which of the following statements regarding triglyceride molecules is false?
A) Triglycerides consist of three fatty acids attached to a glycerol.
B) Triglycerides are hydrophilic.
C) Triglycerides are a type of fat.
D) Triglycerides play a role in energy storage.
35) The development of atherosclerotic disease can result from a diet high in
A) saturated fats.
B) fiber.
C) protein.
34)
D) sugars.
36) If you were to add olive oil to your food as part of a diet to lower your risk of atherosclerotic
disease, you would use olive oil that
A) is modified to be solid at room temperature.
B) has lard added to it.
C) is liquid at room temperature.
D) is hydrogenated.
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35)
36)
37) Which of the following statements about animal cell lipids is false?
A) Phospholipids are important components of cell membranes.
B) Many lipids function as enzymes.
C) Fats are a form of lipid that function to store energy.
D) Cholesterol is a type of lipid that is a component of cell membranes and steroid hormones.
37)
38) A phospholipid is composed of
A) one glycerol molecule linked to one phosphate group and two fatty acids.
B) one fatty acid molecule linked to one glycerol molecule and two phosphate groups.
C) one fatty acid molecule linked to three glycerol molecules.
D) one glycerol molecule linked to three phosphate groups.
38)
39) Which of the following substances is a lipid?
A) enzymes
B) steroids
C) DNA
D) cellulose
39)
40) A major type of lipid found in cell membranes is
A) phospholipids.
B) glycerol.
C) triglycerides.
D) waxes.
40)
41) Which of the following statements about anabolic steroids is false?
A) They promote bone growth.
B) They cause a general buildup of muscle mass.
C) They can stimulate mood swings and violent behavior.
D) They often cause the body to reduce its normal output of sex hormones.
41)
42) Amino acids can be distinguished from one another by
A) the chemical properties of their R groups.
B) the type of bond between the R group and the rest of the amino acid molecule.
C) the number of R groups found on the amino acid molecules.
D) the chemical properties of their amino and carboxyl groups.
42)
43) Proteins differ from one another because
A) each protein contains its own unique sequence of sugar molecules.
B) the number of nucleotides found in each protein varies from molecule to molecule.
C) the sequence of amino acids in the polypeptide chain differs from protein to protein.
D) the peptide bonds linking amino acids differ from protein to protein.
43)
44) Glucose molecules are to starch as ________ are to proteins.
A) fatty acids
B) monosaccharides
C) oils
D) amino acids
44)
45) Peptide bonds
A) form between fatty acids.
C) link amino acids.
45)
B) are formed by a hydrolysis reaction.
D) are used to form amino acids.
46) Which one of the following would be correctly classified as a protein?
A) cholesterol
B) cellulose
C) enzymes
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D) starch
46)
47) Structural proteins
A) include hemoglobin.
B) are found in hair and tendons.
C) include receptor molecules.
D) include ovalbumin, a protein found in egg white.
47)
48) Proteins cannot be denatured by
A) changes in salt concentration.
C) changes in pH.
48)
B) freezing.
D) heat.
49) Which of the following is an example of secondary structure in a protein?
A) an alpha helix
B) a globular shape
C) the joining of two polypeptide chains
D) a particular amino acid sequence
49)
50) The primary structure of a protein is
A) an helix or a pleated sheet.
B) maintained by hydrogen bonds.
C) composed of two or more polypeptide chains.
D) the amino acid sequence of the polypeptide chain.
50)
51) The tertiary structure of a polypeptide refers to
A) its size.
C) the overall three-dimensional structure.
51)
B) the presence of pleated sheets.
D) the amino acids of which it is made.
52) A protein containing more than one polypeptide chain exhibits the ________ level of protein
structure.
A) quaternary
B) secondary
C) tertiary
D) primary
52)
53) How are genes used by cells to build proteins?
A) DNA is transcribed into an amino acid sequence.
B) The genes in RNA direct the synthesis of a DNA molecule, which is used to build a protein.
C) The genes in DNA direct the synthesis of an RNA molecule, which is used to build a protein.
D) The genes in RNA direct the synthesis of proteins directly.
53)
54) Which of the following statements regarding nucleotides is false?
A) Nucleotides contain nitrogenous bases.
B) Nucleotides can be linked together to form nucleic acids.
C) Nucleotides contain lipids.
D) Nucleotides contain sugar molecules.
54)
55) Which of the following options correctly pairs a polymer and its monomer?
A) collagen, nucleic acids
B) cellulose, amino acids
C) RNA, ribose
D) DNA, nucleotides
55)
56) DNA differs from RNA because DNA
A) consists of a single rather than a double polynucleotide strand.
B) contains the sugar ribose rather than the sugar deoxyribose.
C) contains thymine in place of uracil.
D) contains phosphate groups not found in RNA.
56)
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57) How are these two amino acids attached together?
57)
A) amino group to amino group
B) through a hydrolysis reaction
C) carboxylic acid group to carboxylic acid group
D) amino group to carboxylic acid group
58) What change is occurring in this figure?
58)
A) Chlorine is losing an electron.
C) Sodium is filling its third electron shell.
B) Chlorine is filling its third electron shell.
D) Sodium is becoming negatively charged.
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59) The hydrogen bonds shown in this figure are each
59)
A) between an oxygen and a hydrogen atom of the same water molecule.
B) between two atoms with the same charge.
C) between two hydrogen atoms.
D) between an oxygen and a hydrogen atom of different water molecules.
60) These two molecules are structural isomers. What is the difference between them?
A) the location of a double-bonded oxygen atom
B) the number of hydrogen atoms
C) Only one of them has a double bond between carbon atoms.
D) the number of carbon atoms
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60)