객관식
Which of the following statements about acids and bases is supported by research?
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3. Acids and Bases
Acids and Bases
객관식
In the context of acids and bases, which type of cell wall is thinner and does not retain the crystal violet stain in the Gram stain?
A
Gram-positive cell wall
B
Peptidoglycan-rich cell wall
C
Acid-fast cell wall
D
Gram-negative cell wall
검증된 단계별 안내1
Understand the Gram staining process: Gram staining is a method used to classify bacterial species into two groups based on the physical properties of their cell walls. The process involves staining cells with crystal violet dye, followed by a counterstain, usually safranin.
Identify the characteristics of Gram-positive and Gram-negative bacteria: Gram-positive bacteria have a thick peptidoglycan layer in their cell walls, which retains the crystal violet stain, appearing purple under a microscope. Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane, which does not retain the crystal violet stain and appears pink after counterstaining.
Recognize the role of peptidoglycan: Peptidoglycan is a polymer that provides structural strength to the bacterial cell wall. In Gram-positive bacteria, the thick peptidoglycan layer is responsible for retaining the crystal violet stain.
Consider the acid-fast cell wall: Acid-fast bacteria have a unique cell wall structure with a high lipid content, making them resistant to Gram staining. They require a different staining method, such as the Ziehl-Neelsen stain, to be visualized.
Conclude the characteristics of Gram-negative bacteria: Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane, which prevents the retention of the crystal violet stain, resulting in a pink appearance after Gram staining.
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