Microbiology 12

Front 1

Large structures (e.g., ribosomes) form spontaneously from their macromolecular components by a process known as ________.

Back 1

Self-assembly

Front 2

Eukaryotic cells compartmentalize some anabolic and catabolic pathways so that these pathways can be operated _______.

Back 2

Independently

Front 3

Cells save energy and materials by using many of the same enzymes for both __________ and __________.

Back 3

anabolism; catabolism

Front 4

Different proteins have different amino acid __________.

Back 4

sequences

Front 5

T/F

Many enzyme catalyzed reactions are freely reversible; however, some key steps require separate enzymes for the reverse step in order to provide for independent regulation of anabolic and catabolic pathways.

Back 5

True

Front 6

T/F

Nongrowing cells continuously degrade and resynthesize cellular molecules during a process known as cellular turnover.

Back 6

True

Front 7

T/F

The use of compartmentation for the simultaneous but independent regulation of anabolic and catabolic pathways occurs generally in eukaryotes but not in prokaryotes.

Back 7

True

Front 8

Anabolic and catabolic pathways use different cofactors for similar reactions.

Back 8

True

Front 9

In the synthesis of amino acids the addition of the amino nitrogen usually occurs __________ the synthesis of the carbon skeletons.

Back 9

After

Front 10

T/F

Although most autotrophic microorganisms fix carbon dioxide using the Calvin-Benson cycle, this pathway is absent in the Archaea.

Back 10

True

Front 11

T/F

Photoautotrophs are the only organisms that can incorporate (fix) carbon dioxide into biomolecules.

Back 11

False

Front 12

Because peptidoglycan lies outside the plasma membrane, all steps in the complex synthesis process of this molecule takes place outside the cell.

Back 12

False

Front 13

T/F

Nitrogen fixation is used to form ATP, which is then used for energy reserves.

Back 13

False

Front 14

T/F

In the biosynthesis of nucleotides, pyrimidines are assembled starting with ribose-5-phosphate while ribose-5-phosphate is added after synthesis of the nitrogenous base for purines.

Back 14

False

Front 15

Unsaturated fatty acids are those containing carbon-carbon ________ bonds.

Back 15

Double

Front 16

T/F

Bacteria can synthesize unsaturated fatty acids only under anaerobic conditions.

Back 16

False

Front 17

Which of the following is true about the synthesis of macromolecules from monomeric subunits?

A. It saves genetic storage capacity.

B. It saves biosynthetic raw materials.

C. It saves energy.

D. all of the choices

Back 17

D

Front 18

Synthesis of complex molecules from simpler ones with the input of energy is called

A. metabolism.

B. anabolism.

C. catabolism.

D. amphibolism.

Back 18

B

Front 19

Assemblies of macromolecules are referred to as __________ complexes.

A. ultramolecular

B. supramolecular

C. metamolecular

D. maximolecular

Back 19

B

Front 20

There are __________ common amino acids used to synthesize proteins.

A. 20

B. 61

C. 64

D. 25

Back 20

A

Front 21

Large numbers of small monomeric molecules join together to form large molecules that are known as:

A. multimers.

B. polymolecules.

C. macromolecules.

D. maximolecules.

Back 21

C

Front 22

Which of the following is a source of carbon skeletons that are used in the synthesis of amino acids?

A. Acetyl-CoA.

B. TCA cycle intermediates.

C. Glycolysis intermediates.

D. All of the choices.

Back 22

D

Front 23

Microorganisms assimilate large amounts of all of the following except __________ into organic molecules.

A. nitrogen

B. phosphorus

C. sodium

D. sulfur

Back 23

C

Front 24

The process of carbon dioxide fixation refers to

A. release of carbon dioxide during catabolic reactions.

B. reduction of carbon dioxide and incorporation into organic molecules that are assimilated.

C. release of carbon dioxide during anabolic reactions.

D. reaction of carbon dioxide with water to form carbonic acid.

Back 24

B

Front 25

Which pathway(s) are used by eukaryotic microorganisms to fix carbon dioxide?

A. Calvin cycle.

B. Reductive tricarboxylic pathway.

C. Entner-Doudoroff.

D. None of the choices.

Back 25

A

Front 26

Which pathway(s) is used to fix carbon dioxide?

A. Glycolysis.

B. Reductive tricarboxylic pathway.

C. Entner-Doudoroff.

D. Pentose phosphate pathway.

Back 26

B

Front 27

Which of the following is not a phase of the Calvin Cycle?

A. carboxylation phase

B. oxidation phase

C. reduction phase

D. regeneration phase

Back 27

B

Front 28

In order to form a single molecule of glucose, it takes __________ turns through the reactions of the Calvin cycle.

A. 3

B. 4

C. 6

D. 12

Back 28

C

Front 29

Photoautotrophs use light energy directly for

A. the production of ATP and NADPH.

B. the reduction of carbon dioxide to glucose.

C. both the production of ATP and NADPH and the reduction of carbon dioxide to glucose.

D. neither the production of ATP and NADPH nor the reduction of carbon dioxide to glucose.

Back 29

A

Front 30

The photosynthetic production of one molecule of glucose requires __________ molecule(s) of NADPH.

A. 6

B. 12

C. 18

D. 24

Back 30

B

Front 31

The photosynthetic production of one molecule of glucose requires __________ molecule(s) of ATP.

A. 6

B. 12

C. 18

D. 24

Back 31

C

Front 32

The series of enzymatic steps that fixes carbon dioxide into carbohydrate is called the ______.

A. Pentose phosphate pathway

B. Embden-Meyerhoff pathway

C. Calvin cycle

D. Entner-Doudoroff pathway

Back 32

C

Front 33

The synthesis of glucose from non-carbohydrate precursors is called

A. glycolysis.

B. glutamine synthase.

C. gluconeogenesis.

D. none of the choices

Back 33

C

Front 34

In order to synthesize new peptidoglycan for bacterial cell walls, the existing walls must be partially digested by __________ to provide acceptor ends for the new synthesis.

A. lysozyme

B. autolysins

C. autozymogens

D. peptidoglycolysins

Back 34

B

Front 35

__________ is the carrier molecule required to transport peptidoglycan subunits to the location where they will be incorporated into the growing bacterial cell wall.

A. Bactoprenol

B. UDP glucose

C. Acyl carrier protein

D. Malonyl-CoA

Back 35

A

Front 36

__________ reactions are used to replace TCA cycle intermediates that have been used to provide carbon skeletons for amino acid biosynthesis.

A. Amphibolic

B. Anaplerotic

C. Anabolic

D. Catabolic

Back 36

B

Front 37

Symbiotic nitrogen fixation can consume up to __________% of the ATP generated by the host plant.

A. 5

B. 20

C. 30

D. 50

Back 37

B

Front 38

The major reductive amination pathway for incorporation of nitrogen into amino acids initially involves the production of __________ from alpha-ketoglutarate.

A. tryptophan.

B. cysteine.

C. arginine.

D. glutamate.

Back 38

D

Front 39

Most microorganisms assimilate nitrogen as

A. nitrite.

B. hydrazine.

C. nitrate.

D. N2.

Back 39

C

Front 40

The reduction of sulfate as a terminal electron acceptor during anaerobic respiration is called __________ sulfate reduction.

A. assimilatory

B. dissimilatory

C. amodulatory

D. demodulatory

Back 40

B

Front 41

The reduction of sulfate for use in the production of compounds such as cysteine is called __________ sulfate reduction.

A. assimilatory

B. dissimilatory

C. amodulatory

D. demodulatory

Back 41

A

Front 42

Many microbes use pyruvate carboxylase or phosphoenolpyruvate carboxylase to

A. synthesize amino acids.

B. synthesize glucose.

C. synthesize oxaloacetate.

D. synthesize acetyl-CoA.

Back 42

C

Front 43

The reduction of atmospheric nitrogen to ammonia is called

A. ammonification.

B. nitrification.

C. denitrification.

D. nitrogen fixation.

Back 43

D

Front 44

Nitrogen fixation depends on the enzyme nitrogenase which is produced by some

A. Archaea.

B. bacteria.

C. eukaryotes.

D. bacteria and Archaea but no eukaryotes.

E. fungi and bacteria.

Back 44

D

Front 45

Phosphorous is usually assimilated by microorganisms as

A. polyphosphate (volutin).

B. phosphene.

C. elemental phosphate (Po).

D. phosphate.

Back 45

D

Front 46

Which of the following cofactors is very important in the synthesis of purines?

A. acetyl-CoA

B. cytidine diphosphate

C. folic acid

D. glutathione

Back 46

C

Front 47

Assimilation of organic phosphates from the surroundings uses enzymes known as

A. phosphorylases.

B. phosphatases.

C. phosphosynthetases.

D. phosphoisomerases.

Back 47

B

Front 48

Purines and pyrimidines are precursors for synthesis of

A. fatty acids.

B. nucleic acids.

C. proteins.

D. peptidoglycan.

Back 48

B

Front 49

A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, to which is attached one or more phosphate groups is called a:

A. nucleotide.

B. nucleoside.

C. nitrogenous base.

D. nucleic acid.

Back 49

A

Front 50

A purine or pyrimidine that is attached to a sugar, either ribose or deoxyribose, is called a

A. nucleotide.

B. nucleoside.

C. nitrogenous base.

D. nucleic acid.

Back 50

B

Front 51

________ are cyclic nitrogenous bases with two rings and pronounced aromatic properties.

A. Purines

B. Quinones

C. Amino acids

D. Fatty acids

Back 51

A

Front 52

Which of the following is not generally true about fatty acids produced by microorganisms?

A. Fatty acids are monocarboxylic acids.

B. Fatty acids have long alkyl chains.

C. Gram-positive bacteria often make cyclopropane fatty acids.

D. All of these are generally true about fatty acids.

Back 52

C

Front 53

Which of the following do(es) not contribute to the construction of membrane phospholipids?

A. Glycolysis.

B. Fatty acid biosynthesis.

C. Amino acid biosynthesis.

D. Nucleotide biosynthesis.

Back 53

D

Front 54

Unsaturated fatty acids are those containing __________ carbon-carbon double bond(s).

A. only one

B. exactly two

C. one or more

D. two or more

Back 54

C