Microbiology Multiple Choice Questions on “Utilization of Energy in Biosynthetic Processes”.
1. The biosynthesis of proline takes place from ____________
A. aspartic acid
B. glutamic acid
C. pyruvic acid
D. alpha-keto glutaric acid
Answer: B
Clarification: The biosynthesis of proline takes place from glutamic acid in which the initial step utilizes metabolic energy in the form of ATP.
2. Which of the following acts as a precursor for the activation of peptidoglycan?
A. TP
B. UDP
C. NADPH
D. GTP
Answer: B
Clarification: Sugars such as acetylglucosamine are activated by the attachment of a UDP to form a sugar-UDP precursor which is a general method involved in the biosynthesis of peptidoglycan.
3. Bactoprenol is a ___________
A. membrane phospholipid
B. amino acid carrier
C. fatty acid
D. enzyme
Answer: A
Clarification: Bactoprenol is a membrane phospholipid to which the AMA-UDP precursor is coupled during the synthesis of peptidoglycan.
4. Electrons entering the respiratory chain of chemoautotrophic bacteria enter the chain at higher potential.
A. True
B. False
Answer: A
Clarification: Electrons entering the respiratory chain from the oxidation of inorganic substrates by chemoautotrophic bacteria usually enter the chain at a higher point than those electrons from the oxidation of organic substrates by chemoheterotrophs. Thus chemoautotrophs are at a considerable energetic disadvantage for this reason.
5. ATP dependent NADPH2 production is a process found in ______________
A. Nitrosomonas
B. Nitrobacter
C. Rhizobium
D. E.coli
Answer: B
Clarification: Nitrobacter is a chemiautotrophic bacteria that follows the process of ATP-dependent-NADPH2 production for the production of NADPH2 to be used with ATP for carbon dioxide fixation.
6. Each turn of Calvin cycle results in the fixation of ________ molecule of carbon dioxide.
A. one
B. two
C. four
D. six
Answer: A
Clarification: Each turn of the Calvin cycle results in the fixation of one molecule of carbon dioxide. Carbon dioxide is fixed in a reaction with the acceptor molecule ribulose diphosphate.
7. The peptidoglycan layer of Staphylococcus aureus consists of a bridge between muramic acid peptides which is composed of?
A. alanine
B. lysine
C. proline
D. gycine
Answer: D
Clarification: In Staphylococcus aureus a bridge composed of five glycine molecules can link two muramic acid peptides together.
8. Binding proteins for active transport systems of Gram-negative bacteria are associated with ____________
A. cell membrane
B. cytoplasmic membrane
C. periplasmic space
D. nuclear membrane
Answer: C
Clarification: Active-transport of Gram-negative bacteria are associated with binding proteins in the periplasmic space. The binding proteins have very high affinities for specific nutrients, including amino acids, sugars, and inorganic ions.
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