MCB 3020C Module 2 Exam Review Questions and Answers 2024

MCB 3020C Module 2 Exam Review Questions and Answers 2024

• What is the function of the Z ring in binary fission?
• It forms a contractile ring at the septum => Made up of FtsZ (tubulin

homologues) molecules important for bacterial septation

• It controls the replication of DNA => Replisome contains DNA replication machinery
• It separates the newly synthesized DNA molecules => ParA

polymerizes/depolymerizes to attach to ParB which recognizes the DNA Sequence parS which is next to the origin of replication

• Both A and B
• Both B and C

• Which of the following was the first broad-spectrum antibiotic discovered?
• Salvarsan => First Synthetic antibiotic
• Chloramphenicol => Made by a bacterium
• Penicillin => First True antibiotic
• Oxazolidinone => Considered new “drug of last resort”
• Vancomycin 1 / 3

• Which of the following is true about biofilms? (select all that apply)
• Only bacteria of similar strains can form biofilms => Composed of many different

microorganisms

• Heterogeneity among the bacteria can lead to increased interactions and communication

=> Microbes with varying diversity communicate heavily in biofilms via quorum sensing

• Microbes that grow attached to the surfaces of these biofilms are planktonic

=> They are sessile, think plankton are planktonic; they are freely floating

• The most metabolically active cells are located at the base of the biofilm => Slow growers

near the base of the biofilm (Ch. 7 slide 35) not as metabolically active but still active

• They often have an EPS which provides structural and functional support

=> Extracellular polymeric substance makes biofilms tough to remove Ex. Biofilms on surface of teeth can cause damage in the form of cavities and tooth decay; have to scrape it off in a dental procedure. Conventional cleaning agents and antibiotics can’t get past the EPS barrier.

• Which of the following is true in relation to the central dogma of biology?
• DNA is the template for its own replication => Depends on the holoenzyme DNA

polymerase

• The flow of genetic information goes from DNA to RNA to proteins
• mRNA is the template for protein translation
• Both A and C
• All of the above => (Ch. 13 slide 2)

• In regard to proteins: => Made up of single or multiple polypeptides, contain covalent and

non-covalent bonds

• Denaturing results in the loss of secondary structures => Denaturing results in a protein losing

all its structures except their primary structure; Ex. increasing temperature or altering pH 2 / 3

• They grow from the N-terminus to the C-terminus => Starts from the North/ N- terminus

(where cleavage also takes place with signal peptides in order to activate proteins)

• All proteins can have a quaternary structure
• Both A and B
• Both B and C

• Which of the following is false regarding bacterial horizontal gene transfer?
• Bacterial transformation requires bacteria to be competent => DNA taken up from

environment

• Bacterial conjugation requires a form of cell-cell contact to take place, usually through a sex

pilus => Sex pilus for conjugation NOT T4P (type IV pilus); Sex pilus can transfer R plasmid

• It can involve the transfer of genetic material from parent to offspring => This is vertical

gene transfer

• Bacterial transduction involves phages inserting into the host’s genome
• All of the above are true

• Which of the following is false regarding penicillin?
• It can activate autolysins => Breaks bonds in peptidoglycan which allows for easy passage

for NAM and NAG + new addition of them and assists with cellular growth (Needs to be heavily regulated). Penicillins can further activate these to lyse the bacterial cell

• Organisms that produce β-lactamase can become resistant to penicillin => Penicillinase
• Penicillin V and G are narrow spectrum and only work on Gram-positives =>

Ampicillin is semi-synthetic and has a broader spectrum than V and G

• It is responsible for blocking peptide elongation => Deals with protein synthesis

inhibition not involved with penicillin (cell wall inhibitor)

• It is a true antibiotic that is made by a fungus => Penicillium (fungi)
• / 3