Question

Gram-staining is a procedure that microbiologists use to a. determine if a bacterial strain is a pathogen. b. determine if a sample of bacteria sample can break down oil. c. infer the structure of the cell wall of bacteria and their response to antibiotics. d. count bacteria in medical or environmental samples. e. do all of the above.

Short answer

The correct choice is 'c'. Gram staining can infer the structure of the cell wall of bacteria and their response to antibiotics.

Step-by-step solution

Understand the nature of each option

This step requires understanding what each option is proposing and comparing it to the recognized applications of Gram staining. It's obvious from the start that Gram staining doesn't provide functionality for pathogen identification, oil breakdown, or bacteria counting.

Eliminate incorrect choices

Eliminate options 'a', 'b', 'd', and 'e' for the reasons stated in Step 1. Gram staining is specifically used to infer the structure of the bacterial cell wall and their response to antibiotics.

Select the more accurate option

The remaining choice 'c' states that Gram staining can infer the structure of the cell wall of bacteria and their response to antibiotics. This aligns perfectly with the concept and purpose of Gram staining, providing us with the correct answer.

Key concepts

Bacterial Cell Wall

The bacterial cell wall is a crucial structure that determines the shape and integrity of the bacterium. It is like an armor for the bacteria, protecting them from the external environment. The cell wall composition varies between different bacterial species and is a key factor in their classification through Gram-staining. The main components of a bacterial cell wall are peptidoglycan layers. These layers are much thicker in Gram-positive bacteria compared to Gram-negative bacteria.

• In Gram-positive bacteria, the thick peptidoglycan layer retains the crystal violet stain used in the Gram-staining process, giving them a purple color under a microscope.
• In contrast, Gram-negative bacteria have a thinner peptidoglycan layer and an outer membrane, which does not retain the crystal violet stain but takes up the safranin counterstain, appearing pink.

Understanding the structure of the bacterial cell wall can help infer their survival mechanisms and their interaction with antibiotics, as different antibiotics target the cell wall in varied ways.

Microbiology

Microbiology is the study of microorganisms, including bacteria, viruses, fungi, and archaea. This field is essential for understanding the basic life processes and their roles in health, disease, and the environment. Gram-staining is a fundamental technique in microbiology. It helps microbiologists classify bacteria into two groups: Gram-positive and Gram-negative, based on the cell wall composition.
With this classification, microbiologists can determine which antibiotics might be effective. This methodology is vital in clinical settings, where understanding the type of bacteria can lead to proper treatment of bacterial infections. Microbiology also extends beyond clinical application to environmental research and biotechnology.
The knowledge gained from microbiology is used in the

• development of new vaccines,
• bioremediation techniques,
• and understanding microbial pathogenesis and interactions with hosts.

Antibiotic Response

Antibiotic response refers to how bacteria react to antibiotics, which are substances used to treat bacterial infections. The structure of the bacterial cell wall is a significant factor in determining the effectiveness of an antibiotic.
Antibiotics work by targeting specific features of bacterial cells, often involving the cell wall. For example, penicillin targets the peptidoglycan layer, disrupting the cell wall and causing the bacteria to die.
Since Gram-positive bacteria have a thicker peptidoglycan layer, they are more susceptible to certain antibiotics, like penicillin. On the other hand, Gram-negative bacteria, with their protective outer membrane and thinner peptidoglycan layer, can resist some antibiotics.
This resistance is problematic and leads to the need for more potent or combination therapies to effectively treat infections caused by Gram-negative bacteria.

Gram-positive and Gram-negative Bacteria

Gram-positive and Gram-negative bacteria are distinguished by their cell wall structures and their reaction to the Gram-staining technique. This classification is not just a laboratory convenience but has profound implications for bacterial physiology and treatment options.

• Gram-positive bacteria typically have a thicker peptidoglycan layer, lack an outer membrane, and stain purple in the Gram-staining process.
• Gram-negative bacteria have a thinner peptidoglycan layer, an outer membrane, and stain pink due to taking up the counterstain rather than the primary stain.

The differences in cell wall structure influence their permeability and vulnerability to antibiotics. This knowledge is crucial for developing targeted antibiotic therapies. Additionally, Gram-negative bacteria often exhibit greater resistance to antibiotics due to their robust outer membrane, which acts as a barrier to many drugs. Understanding these differences supports effective clinical decision-making and the development of new antimicrobial strategies.