Deck 2: The Chemistry of Microbiology

Question 1

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

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

Answer 1

C

Question 2

The type(s) of bond produced when atoms with significantly 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) nonpolar covalent and ionic bonds.

Answer 2

B

Question 3

An atom is electrically neutral when

A) the number of electrons equals the number of neutrons.
B) the numbers of its protons, electrons, and neutrons are all equal.
C) it has no extra electrons in its valence shell.
D) the number of protons equals the number of neutrons.
E) the number of electrons equals the number of protons.

Answer 3

E

Question 4

Which of the following is an incorrect pairing?

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

Question 5

All of the following are associated with atomic structure EXCEPT

A) valence.
B) dalton.
C) monomer.
D) electron shell.
E) neutron.

Question 6

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 7

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 non-polar molecule.

Question 8

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 9

Fats, proteins, and complex carbohydrates are all produced by

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

Question 10

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 11

An atom of carbon that has six protons and seven neutrons is an example of a(n)

A) isotope.
B) radioactive isotope.
C) molecule.
D) compound.
E) dalton.

Question 12

Which pH would be alkaline?

A) 7.0
B) 8.0
C) 4.0
D) 1.5
E) 6.5

Question 13

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) polar covalent and ionic bonds.

Question 14

Which of the following is a particle that is found in the nucleus of an atom and has no electrical charge?

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

Question 15

Compounds that readily dissociate in water are

A) nonpolar.
B) ionic.
C) polar.
D) either polar or ionic.
E) never polar or ionic.

Question 16

Which parts of the atoms interact in a chemical reaction?

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

Question 17

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 18

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 19

All of the following are associated with ionic bonds EXCEPT

A) cations.
B) radioactivity.
C) electrolytes.
D) salts.
E) anions.

Question 20

Which of the following types of chemical bonds do carbon atoms generally NOT form?

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

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

The "spine" of the DNA molecule is composed of

A) amino acids.
B) pentoses.
C) phosphates.
D) nitrogenous bases.
E) alternating phosphates and pentoses.

Question 23

A protein is a __________ of amino acids.

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

Question 24

Lipids found in the membranes of all eukaryotic cells are

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

Question 25

Which of the following is found in nucleic acids?

A) ionic bonds
B) peptide bonds
C) purines
D) ß-sheets
E) disulfide bridges

Question 26

Which of the following statements concerning nucleic acids is FALSE?

A) Nucleic acid strands are held together by hydrogen bonds between complementary bases.
B) Not all DNA is double stranded.
C) Some viruses have DNA as their genomes.
D) The nucleic acid polymer is composed of peptide bonds.
E) Cytosine is found in all nucleic acid molecules.

Question 27

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 28

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 29

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 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

All of the following are components of an amino acid EXCEPT

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

Question 32

The presence of __________ in the cell wall of a microbe causes it to be resistant to drying.

A) fats
B) phospholipids
C) sterols
D) glycolipids
E) waxes

Question 33

Which of the following is an example of a polysaccharide?

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

Question 34

An increase in the pH of a solution by 2 whole numbers represents a change in the number of hydrogen ions by what factor?

A) 2
B) 20
C) 1000
D) 10
E) 100

Question 35

Plant cell walls are composed of __________ held together by __________.

A) polysaccharides, hydrogen bonds
B) amino acids, peptide bonds
C) disaccharides, hydrophobic interactions
D) fatty acids, polar covalent bonds
E) peptidoglycan, ionic bonds

Question 36

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 37

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 38

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 39

Some __________ are used as hormones.

A) phospholipids
B) waxes
C) steroids
D) ions
E) polyunsaturated fats

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

Monosaccharides are usually found in cyclic forms.

Question 42

The electron shells of atoms hold eight electrons each.

Question 43

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

Question 44

Cell surface markers composed of both carbohydrate and lipid molecules are known as __________.

Question 45

Glucose is an example of what type of carbohydrate?

A) a disaccharide
B) a monomer
C) a pentose
D) a pentose polymer
E) a hexose monomer

Question 46

A polymer composed of simple sugars is a(n)

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

Question 47

Adenosine triphosphate (ATP) is a

A) monomer.
B) polymer.
C) simple carbohydrate.
D) lipid.
E) bilayer.

Question 48

Hydrogen bonds are stronger then covalent bonds.

Question 49

Molecules such as amino acids that have identical atoms and functional groups, but are mirror images of each other, are __________.

Question 50

One of the products of dehydration synthesis reactions is water.

Question 51

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

Question 52

The smallest chemical units of matter are elements.

Question 53

Carbohydrates are composed of carbon, hydrogen, and oxygen.

Question 54

An amino acid is an example of a

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

Question 55

Another name for a unit of atomic mass is a(n) __________.

Question 56

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 57

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

Question 58

Prokaryotes that grow best under acidic conditions are called __________.

Question 59

Amylose is a(n) __________ carbohydrate.

A) simple
B) monomer
C) polymer
D) nucleotide
E) ionic

Question 60

Denaturation of a protein is always permanent.

Question 61

The sum of all the chemical reactions within an organism is referred to as its __________.

Question 62

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

Question 63

The DNA double helix is held together by __________ bonds.

Question 64

A(n) __________ is any molecule that speeds up a chemical reaction.

Question 65

Compare and contrast synthesis reactions with decomposition reactions.

Question 66

The __________ of an element vary in the number of neutrons in the nucleus.

Question 67

The folding of a polypeptide into a three-dimensional shape is its __________ structure.

Question 68

A(n) __________ is a substance that maintains the pH even when the amounts of acid and/or base are changing.

Question 69

The monomer of a nucleic acid is called a(n) __________.

Question 70

Define and discuss the importance and impact of pH on living organisms.

Question 71

A(n) __________ is a molecule that binds with hydrogen ions when it is dissolved in water.

Question 72

A chemical reaction that traps energy within newly formed chemical bonds is a(n) __________ reaction.

Question 73

A six-carbon sugar is called a(n) __________.

Question 74

A chemical reaction in which a water molecule is a reactant is known as a(n) __________ reaction.

Question 75

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

Question 76

Nitrogen is an essential element for living things, as demonstrated by the fact that nearly all fertilizers contain nitrogenous compounds. Discuss why nitrogen is essential.