Deck 2: The Chemistry of Microbiology

Question 1

Which of the following are responsible for the reactivity of atoms with each other in chemical reactions?

A) valence electrons
B) protons
C) neutrons
D) atomic nuclei
E) radioactive isotopes

Answer 1

A

Question 2

The type of bond produced when atoms share electrons is a(n)

A) covalent bond.
B) hydrogen bond.
C) ionic bond.
D) Both A and B are correct.
E) A, B, and C are correct.

Answer 2

A

Question 3

When water molecules interfere with the ionic bonds of salts, this process is called

A) dehydration.
B) dissociation.
C) detachment.
D) denaturation.
E) decomposition.

Answer 3

B

Question 4

A calcium atom has a valence of +2. This means that calcium can

A) give up 2 electrons.
B) receive 2 electrons.
C) react with an atom that has a valence of - 2.
D) Both A and C are correct.
E) Both B and C are correct.

Question 5

All of the following are uses of carbohydrates in organisms EXCEPT:

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

Question 6

Which of the following is NOT associated with phospholipids?

A) glycerol
B) micelles
C) bilayers
D) fatty acids
E) fused carbon rings

Question 7

The production of carbon dioxide and water from glucose is an example of a(n) reaction.

A) catabolic
B) exothermic
C) decomposition
D) Both B and C are correct.
E) A, B, and C are correct.

Question 8

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

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

Question 9

Which of the following describes an isotope of an atom?

A) It has more neutrons than protons.
B) It does not have any neutrons.
C) The number of its protons, neutrons, and electrons are all equal.
D) It has more protons than electrons.
E) It has more electrons than protons.

Question 10

Which of the following types of lipids can be used to keep some microorganisms from drying out?

A) unsaturated fats
B) waxes
C) saturated fats
D) polyunsaturated fats
E) steroids

Question 11

All of the following are characteristics of a carbon atom that makes it useful to life EXCEPT:

A) it can form very long molecular chains.
B) it is used in the formation of important molecules such as proteins.
C) it can share electrons with other atoms.
D) it can serve as a four- way "intersection" in a molecule.
E) it has three naturally occurring isotopes.

Question 12

Which pH would be alkaline?

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

Question 13

All of the following are associated with ionic bonds EXCEPT:

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

Question 14

All of the following are true statements concerning polar covalent bonds EXCEPT:

A) They occur between two atoms with significantly different electronegativities.
B) They contribute to the water solubility of a molecule.
C) They involve unequal sharing of electrons.
D) Water is an example of a molecule with this type of bond.
E) They involve cations and anions.

Question 15

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

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

Question 16

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

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

Question 17

Which of the following is an incorrect pairing?

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

Question 18

All of the following are characteristics of saturated fats EXCEPT:

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

Question 19

All of the following are associated with atomic structure EXCEPT:

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

Question 20

All of the following are properties of water EXCEPT:

A) water has three polar covalent bonds.
B) water has a high capacity for heat.
C) water is a product of dehydration synthesis.
D) many solutes will dissolve in water.
E) hydrogen bonds form the connection between water molecules.

Question 21

All of the following bases are found in RNA molecules EXCEPT:

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

Question 22

Monosaccharides are usually found in cyclic forms.

Question 23

Which of the following is a true statement concerning cellulose?

A) It is a polymer of glucose.
B) It contains a- 1,4 bonds.
C) It is a long, unbranched molecule.
D) Both B and C are true.
E) Both A and C are true.

Question 24

The smallest chemical units of matter are atoms.

Question 25

All of the following statements concerning nucleic acids are true EXCEPT:

A) Not all DNA is double stranded.
B) Nucleic acids have a linear "spine" composed of alternating sugars and bases.
C) Cytosine is found in all nucleic acid molecules.
D) Some viruses use DNA in their genomes.
E) Nucleic acid strands are held together by hydrogen bonds between complementary bases.

Question 26

All of the following are associated with proteins EXCEPT:

A) pyrimidines.
B) disulfide bridges.
C) peptide bonds.
D) enzymes.
E) a- helices.

Question 27

Hydrogen bonds would be found in all of the following EXCEPT:

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

Question 28

The electron shells of atoms hold eight electrons each.

Question 29

All of the following are components of an amino acid EXCEPT:

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

Question 30

All of the following are classified as macromolecules EXCEPT:

A) amino acids.
B) carbohydrates.
C) proteins.
D) lipids.
E) nucleic acids.

Question 31

All of the following are associated with the structure of DNA molecules EXCEPT:

A) phosphate.
B) pentose sugars.
C) high- energy bonds.
D) antiparallel strands.
E) hydrogen bonds.

Question 32

Which of the following is an example of a pyrimidine?

A) thymine
B) guanine
C) adenine
D) Both B and C are correct.
E) A, B, and C are correct.

Question 33

Which of the following is an incorrect pairing?

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

Question 34

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

Question 35

Which of the following is an example of a polysaccharide?

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

Question 36

All of the following can cause disruptions in the three- dimensional structure of proteins EXCEPT:

A) changes in temperature.
B) changes in salt concentration.
C) changes in pH.
D) amino acid substitutions.
E) changes in fatty acid composition.

Question 37

All of the following are associated with ATP molecules EXCEPT:

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

Question 38

Hydrogen bonds are weaker than covalent bonds.

Question 39

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

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

Question 40

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) 100
B) 1,000
C) 10
D) 2
E) 20

Question 41

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

Question 42

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

Question 43

are lipids that consist primarily of four fused rings of carbon.

Question 44

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

Question 45

Carbohydrates are composed of carbon, hydrogen, and oxygen.

Question 46

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

Question 47

Inorganic chemicals useful to living things include water, sterols, and metal ions.

Question 48

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

Question 49

A six- carbon sugar used for energy in cells is called a(n) .

Question 50

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

Question 51

Denaturation of a protein is always permanent.

Question 52

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

Question 53

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

Question 54

Organisms function only within narrow pH ranges.

Question 55

A(n) is a ball- shaped structure composed of a single layer of phospholipids.

Question 56

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

Question 57

In organic molecules, the letter designates atoms that vary from one molecule to another within a class.

Question 58

Matter composed of a single type of atom is called a(n) .

Question 59

Molecules that are insoluble in water are often called , which literally means "water- fearing."

Question 60

A(n) is an atom that has a full negative charge.

Question 61

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

Question 62

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

Question 63

Compare and contrast synthesis reactions with decomposition reactions.

Question 64

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

Question 65

Discuss the importance of the element phosphorus to living organisms.