MCB 150 SECTION 1 2026 CELL
STRUCTURE AND BIOMOLECULES REVIEW
COMPLETE NOTES
◉ What is a characteristic of endotoxins?
Answer: Endotoxins cause fever.
◉ What is a characteristic of exotoxins?
Answer: Exotoxins can cause cytokine storms.
◉ Describe biofilms.
Answer: Biofilms are highly structured communities.
◉ Which step in biofilm formation comes immediately after
planktonic cells attach to a surface?
Answer: Planktonic cells become sessile.
◉ Which biofilms are produced by mutualistic microbes and are
beneficial to a human host?
Answer: Biofilms that line the intestinal mucosa.
, ◉ Why would bacteria living in a biofilm slow down their
metabolism?
Answer: To survive the low-nutrient environment deep in the
biofilm structure.
◉ Which type of microscopy allows the visualization of internal
cellular structures in specially fixed microbial specimens?
Answer: Electron microscopy
◉ What does a phase-contrast microscope use to visualize a
specimen?
Answer: Light
◉ Which type of microscopy produces highly detailed three-
dimensional images of a specimen?
Answer: Scanning electron microscopy
◉ Which method of microscopy uses a laser to scan multiple planes
and produces a three-dimensional image that can be used to
visualize the internal structure of a biofilm?
Answer: Confocal microscopy
◉ Which technique uses a single dye to emphasize particular
structures in the specimen?
STRUCTURE AND BIOMOLECULES REVIEW
COMPLETE NOTES
◉ What is a characteristic of endotoxins?
Answer: Endotoxins cause fever.
◉ What is a characteristic of exotoxins?
Answer: Exotoxins can cause cytokine storms.
◉ Describe biofilms.
Answer: Biofilms are highly structured communities.
◉ Which step in biofilm formation comes immediately after
planktonic cells attach to a surface?
Answer: Planktonic cells become sessile.
◉ Which biofilms are produced by mutualistic microbes and are
beneficial to a human host?
Answer: Biofilms that line the intestinal mucosa.
, ◉ Why would bacteria living in a biofilm slow down their
metabolism?
Answer: To survive the low-nutrient environment deep in the
biofilm structure.
◉ Which type of microscopy allows the visualization of internal
cellular structures in specially fixed microbial specimens?
Answer: Electron microscopy
◉ What does a phase-contrast microscope use to visualize a
specimen?
Answer: Light
◉ Which type of microscopy produces highly detailed three-
dimensional images of a specimen?
Answer: Scanning electron microscopy
◉ Which method of microscopy uses a laser to scan multiple planes
and produces a three-dimensional image that can be used to
visualize the internal structure of a biofilm?
Answer: Confocal microscopy
◉ Which technique uses a single dye to emphasize particular
structures in the specimen?
