Deck 2: The Chemistry of Microbiology

Question 1

Unstable isotopes can be useful

A) catalysts.
B) in medical diagnosis.
C) in vitamins.
D) in the formation of hydrogen bonds.
E) as buffers.

Answer 1

B

Question 2

Which of the following is an incorrect pairing?

A) electrolytes; anions
B) synthesis; endothermic
C) hydrolysis; hydrogen bonds
D) catabolism; exothermic
E) dehydration; anabolism

Answer 2

C

Question 3

The type(s)of bond produced when atoms share electrons equally is/are

A) a nonpolar covalent bond.
B) a hydrogen bond.
C) an ionic bond.
D) a polar covalent bond.
E) both polar covalent and ionic bonds.

Answer 3

A

Question 4

Which of the following is a property of water?

A) it has a high capacity for heat.
B) it is not a common reactant in metabolic reactions.
C) It is not a good solvent.
D) it is liquid in a very narrow temperature range.
E) it is a nonpolar molecule.

Question 5

Which parts of the atoms interact in a chemical reaction?

A) protons
B) neutrons
C) ions
D) electrons
E) isotopes

Question 6

Which of the following is NOT a characteristic of saturated fats?

A) they are usually solid at room temperature.
B) they contain at least one double bond.
C) they are found in animals.
D) their fatty acids pack tightly together.
E) they are a form of stored energy.

Question 7

Which of the following is NOT a characteristic of phospholipids?

A) they are found in cellular membranes.
B) they can form micelles and bilayers.
C) they contain fatty acids that associate with water.
D) they contain a hydrophilic phosphate "head."
E) they contain two fatty acids and a phosphate functional group.

Question 8

A weak acid may function as a

A) transfer group.
B) buffer.
C) hydroxyl donor.
D) cation.
E) salt.

Question 9

The carbon atoms in organic compounds typically form ________ with other atoms.

A) nonpolar covalent bonds
B) polar covalent bonds
C) ionic bonds
D) hydrogen bonds
E) either ionic or hydrogen bonds

Question 10

Nucleic acids,proteins,and complex carbohydrates are all produced by

A) hydrolytic reactions.
B) dehydration synthesis.
C) exchange reactions.
D) hydrogen bonding.
E) catabolic reactions.

Question 11

The reverse of a dehydration synthesis reaction is a(n)________ reaction.

A) anabolic
B) exchange
C) hydrolytic
D) endothermic
E) metabolic

Question 12

Organisms use carbohydrates in all of the following ways EXCEPT

A) as a component of cell walls.
B) as a long-term energy source.
C) as a short-term energy source.
D) to keep membranes flexible at low temperatures.
E) as a building block of DNA and RNA molecules.

Question 13

A stable atom has ________ in its valence shell.

A) 4 electrons
B) 2 neutrons
C) 8 electrons
D) 8 protons
E) 10 electrons

Question 14

An acid dissociates in water to release

A) hydrogen ion(s).
B) cation(s).
C) hydroxyl group(s).
D) anion(s).
E) both anions and hydrogen ions.

Question 15

The atomic mass of this stable isotope atom (Figure)is

A) 4.
B) 6.
C) 10.
D) 12.
E) cannot be determined from the available information

Question 16

Matter composed of a single type of atom is known as a(n)

A) element.
B) mineral.
C) molecule.
D) compound.
E) electron.

Question 17

Which of the following does not contribute significantly to the mass of an atom?

A) electron
B) neutron
C) element
D) proton
E) isotope

Question 18

The type(s)of bond produced when atoms with somewhat different electronegativities share electrons is/are

A) a nonpolar covalent bond.
B) a polar covalent bond.
C) an ionic bond.
D) a hydrogen bond.
E) both nonpolar covalent and ionic bonds.

Question 19

A compound that dissociates in water to produce ________ is called a salt.

A) hydrogen ions
B) anions
C) hydroxyl ions
D) cations
E) anions and cations

Question 20

The valence of an atom represents its

A) ability to interact with other atoms.
B) electronegativity.
C) radioactivity.
D) ability to attract electrons.
E) ability to interact with water.

Question 21

All of the following bases are found in RNA molecules EXCEPT

A) adenine.
B) thymine.
C) uracil.
D) cytosine.
E) guanine.

Question 22

Cell walls containing ________ provide the best protection from drying.

A) polysaccharides
B) triglycerides
C) waxes
D) peptidoglycan
E) sterols

Question 23

Which of the following is an example of a polysaccharide?

A) glycogen
B) glucose
C) fructose
D) deoxyribose
E) sucrose

Question 24

Which of the following is found in nucleic acids?

A) amines
B) carboxylic acid
C) purines
D) glycerol
E) R group

Question 25

Which of the following statements concerning nucleic acids is CORRECT?

A) Nucleic acid strands are held together by hydrogen bonds between adjacent carbohydrates.
B) Cellular DNA is double stranded.
C) All viruses have DNA genomes.
D) The nucleic acid polymer is composed of peptide bonds.
E) There are three naturally occurring purines in nucleic acids.

Question 26

All of the following are components of an amino acid EXCEPT a(n)

A) carboxyl group.
B) pentose group.
C) amino group.
D) α-carbon.
E) R group.

Question 27

Which of the following is an incorrect pairing?

A) primary structure; amino acid sequence
B) secondary structure; disulfide bridges
C) tertiary structure; covalent bonds
D) quaternary structure; two or more polypeptides
E) secondary structure; β-pleated sheets

Question 28

All of the following are associated with ATP molecules EXCEPT

A) a long-term energy supply.
B) high-energy bonds.
C) a recyclable energy supply.
D) formation of coenzymes.
E) three phosphate groups.

Question 29

A(n)________ is a compound that dissolves into anions and cations in water.

A) acid
B) buffer
C) base
D) salt
E) catalyst

Question 30

Which of the following would NOT normally be found as a component of a cell's nucleic acids?

A) adenine deoxyribonucleotides
B) thymine deoxyribonucleotides
C) uracil deoxyribonucleotides
D) cytosine ribonucleotides
E) adenine ribonucleotides

Question 31

Decomposition reactions are commonly ________ reactions.

A) endothermic
B) exchange
C) exothermic
D) anabolic
E) dehydration

Question 32

Which of the following statements about proteins is FALSE?

A) They are composed of amino acids.
B) They have multiple levels of structural organization.
C) They can be hydrophobic, hydrophilic, or both.
D) Their primary function is energy storage.
E) They are formed by dehydration synthesis reactions.

Question 33

The double-strands of DNA result from the formation of ________ between the bases.

A) covalent bonds
B) peptide bonds
C) ionic bonds
D) hydrogen bonds
E) α−1,4 bonds

Question 34

A protein is a ________ of amino acids.

A) monomer
B) polymer
C) bilayer
D) solution
E) decomposition product

Question 35

Hydrogen bonds are found in all of the following EXCEPT

A) between phosphates in ATP.
B) in α-helices.
C) between water molecules.
D) in the DNA double helix between nucleotides.
E) between the R groups of amino acids in proteins.

Question 36

A(n)________ is an arrangement of atoms found in a variety of macromolecules.

A) buffer
B) isotope
C) salt
D) stereoisomer
E) functional group

Question 37

Tertiary and quaternary structure of proteins involves ________ bonds.

A) hydrogen
B) ionic
C) polar covalent
D) nonpolar covalent
E) ionic, hydrogen, polar, and nonpolar covalent

Question 38

Lipids found in the cytoplasmic membranes of all eukaryotic cells are

A) polyunsaturated fats.
B) phospholipids.
C) steroids.
D) waxes.
E) triglycerides.

Question 39

Which of the following are examples of pyrimidines?

A) uracil and adenine
B) cytosine and guanine
C) thymine and adenine
D) thymine and guanine
E) cytosine and thymine

Question 40

Proteins contain both acidic and basic R groups and can,therefore,function as

A) energy storage macromolecules.
B) structural macromolecules.
C) buffers.
D) catalysts.
E) genetic material.

Question 41

Anna is conducting an experiment using a pH indicator that is red at low pH,green at neutral pH and purple at high pH.She starts with a green solution.When she adds compound X to her solution it turns purple.Then she adds compound Z to the solution and it turns green.She adds more Z,the solution remains green.These observations suggest X is ________ and Z is ________.

A) a base; a buffer
B) an acid; a base
C) a base; a strong acid
D) an acid; a buffer
E) a buffer; a base

Question 42

Denaturation of a protein is always permanent.

Question 43

A(n)(nonpolar/polar/ionic/hydrogen)bond is one in which electrons are shared equally between atoms.

Question 44

An organic molecule with the chemical formula C₄H₅O₁N₃ is probably a pyrimidine.

Question 45

A molecule composed of carbon and hydrogen is a compound.

Question 46

The long-term chemical energy storage molecules in plants are steroids.

Question 47

DNA is composed of repeating units of sugars,phosphates,and nucleic acids.This is an example of a

A) polymer.
B) monomer.
C) salt.
D) micelle.
E) lipid.

Question 48

Salts are produced from exchange reactions in which acids and bases neutralize each other.

Question 49

The electron shells of atoms hold eight electrons each.

Question 50

Two molecules react to produce two products,one of which is water.What type of reaction is likely to be involved?

A) a decomposition reaction
B) a hydrolysis reaction
C) an exchange reaction
D) a synthesis reaction
E) The answer cannot be determined from the available information.

Question 51

Cell surface markers composed of both carbohydrate and lipid molecules are known as (glycoproteins/glycolipids/LPS).

Question 52

Which of the following is found in RNA but not DNA?

A) adenine
B) cytosine
C) deoxyribose
D) guanine
E) uracil

Question 53

The side groups of amino acids can interact with each other and with other molecules.

Question 54

An unbranched polymer composed of simple sugars is a(n)

A) protein.
B) triglyceride.
C) starch.
D) glycoprotein.
E) amino acid.

Question 55

Hydrogen bonds are stronger then covalent bonds.

Question 56

Which of the following is an organic compound?

A) adenine
B) carbon dioxide
C) molecular oxygen
D) sodium chloride
E) water

Question 57

Dehydration synthesis is a common feature of polymer production in cells.

Question 58

The smallest chemical units of matter are elements.

Question 59

An atom or molecule becomes a(n)(anion/ion/cation)when it loses an electron to a more electronegative molecule.

Question 60

Radioactive iodine is sometimes used to treat thyroid cancer.This is an example of the use of (isotopes/elements/radiation)in medical treatment.

Question 61

A(n)(catalyst/enzyme)is any molecule that speeds up a chemical reaction.

Question 62

A saturated fatty acid contains (no/one/multiple)double bonds.

Question 63

Compare and contrast synthesis reactions with decomposition reactions.

Question 64

Max is exploring the properties of various compounds.Some of his explorations involve the use of a pH indicator that is red at low pH,yellow-green at neutral pH and blue to purple at high pH.He sets up several tubes containing water and the pH indicator and then begins to add some of the compounds he is characterizing in various combinations.His results are shown on the following table.

What can Max conclude about his compounds based on these results? Describe the likely events in terms of hydrogen and hydroxyl ions.

Question 65

Describe the chemical properties of phospholipids that account for their behavior in water.

Question 66

Consider the structure of thymine,shown on the left in Figure above,and compare to the structure of pyrimidine X on the right.What would be the impact if X is incorporated into the structure of a DNA strand in place of thymine?

Question 67

A chemical reaction in which a water molecule is a reactant is known as a (dehydration/hydrolysis)reaction.

Question 68

Jim adds an acid to a solution,but finds the pH has not changed afterward.This suggests the solution contains a(n)(anion/buffer/salt).

Question 69

The monomer of a nucleic acid is called a (nucleoside/nucleotide/base).

Question 70

The folding of a polypeptide into a three-dimensional shape is its (secondary/tertiary/quaternary)structure.

Question 71

Figure depicts the (primary/secondary/tertiary)structure of a protein.

Question 72

Discuss the importance of hydrogen bonds in the chemistry of the cell.

Question 73

The DNA double helix is held together by (covalent/ionic/hydrogen)bonds.

Question 74

The (atoms/isotopes/stereoisomers)of an element vary in the number of neutrons in the nucleus.

Question 75

When a base dissolves in water it releases a(n)(electron/cation/hydrogen ion).

Question 76

A nitrogenous base composed of two rings is a (purine/pyrimidine/ribose).