Question

Vibrio cholerae (shown below) are highly pathogenic bacteria that are associated with severe gastrointestinal illness and are the causative agent of cholera. In extreme cases, antibiotics are prescribed that target bacterial structures that are absent in animal cells. Which of the following structures is most likely targeted by antibiotic treatment? (A) Cytoplasm (B) Plasma membrane (C) Ribosomes (D) Cell wall

Short answer

The most likely target of antibiotic treatment among the given options is (D) Cell wall, as it is exclusive to bacterial cells and not present in animal cells.

Step-by-step solution

Rule out structures present in both bacterial and animal cells

To determine the correct answer, we can begin by ruling out structures that are common to both bacterial and animal cells. Since antibiotics aim to target bacterial structures that are absent or significantly different in animal cells, this will help us narrow down the options. Cytoplasm, Plasma membrane, and Ribosomes are present in both bacterial and animal cells.

Identify the structures exclusive to bacterial cells

From the remaining option, we can focus on the one that is more specific to bacterial cells. The bacterial cell wall is a structure that is exclusive to bacterial cells. Animal cells do not have a cell wall.

Select the bacterial structure most likely targeted by antibiotic treatment

Given that the antibiotic treatment aims to target structures unique to bacteria without affecting animal cells, the most likely target among the given options would be: (D) Cell wall, as it is exclusive to bacterial cells and not present in animal cells.

Key concepts

Bacteria and Antibiotics

Bacteria are tiny microorganisms that can cause various infections and diseases. Some bacteria can be harmful and are known as pathogenic bacteria. To combat these harmful bacteria, antibiotics are often prescribed. Antibiotics are powerful medicines designed to kill or inhibit the growth of these microorganisms, keeping infections at bay.

They work by targeting specific structures or processes within bacterial cells, which are essential for their survival and replication. Understanding that antibiotics are directed at parts of bacteria that are not present in animal cells, such as humans, is crucial. This targeting helps minimize harm to the patient's own cells while efficiently dealing with the infection.

When doctors prescribe antibiotics, they aim to disrupt the bacteria's ability to reproduce or maintain their structural integrity. This means attacking unique bacterial features, ensuring that human cells remain unaffected while the bacteria are effectively combated.

Bacterial Cell Wall

One of the key targets for antibiotics within bacterial cells is the cell wall. The cell wall serves as a rigid protective layer, crucial for maintaining the bacterium's shape and structural integrity.

Unlike bacteria, animal cells do not have a cell wall. This absence allows antibiotics to target the bacterial cell wall selectively, without damaging animal cells. For example, penicillin is an antibiotic that works by interfering with the synthesis of the bacterial cell wall, leading to cell lysis and death.

Here are some important points about bacterial cell walls and antibiotic interactions:

• The cell wall is primarily composed of peptidoglycan, a molecule unique to bacteria, which gives it both strength and rigidity.
• Without a properly functioning cell wall, bacteria are vulnerable to changes in environmental pressures and can burst open.
• Targeting the cell wall ensures that antibiotics disrupt a fundamental aspect of bacterial life, cutting off the infection at its source.

Understanding the role and structure of the bacterial cell wall helps in mastering how antibiotics work to treat bacterial infections.

Pathogenic Bacteria

Pathogenic bacteria are types of bacteria that can cause diseases in humans and other organisms. Not all bacteria are harmful; in fact, many play useful roles in ecological and bodily functions.

However, pathogenic bacteria have adaptations that allow them to manipulate host systems, causing illness. Vibrio cholerae is one such example, known for causing cholera, a severe intestinal infection that leads to dehydration and can be life-threatening.

Key characteristics of pathogenic bacteria include:

• Ability to produce toxins that interfere with host functions.
• Possession of structures like pili or flagella that enable movement and attachment to host cells.
• Mechanisms to evade the host's immune system, allowing them to survive and multiply.

It's crucial to understand what makes these bacteria pathogenic to appreciate how treatment strategies like antibiotics work to disarm such organisms effectively.

Animal Cell Structures

Animal cells are eukaryotic, meaning they have a distinct nucleus and various specialized structures within them. Unlike bacterial cells, animal cells do not have a cell wall, a fact leveraged by antibiotic treatments.

Here are some key structures found in animal cells:

• Plasma Membrane: A flexible boundary that surrounds and protects the cell, controlling the entry and exit of substances.
• Nucleus: Contains the genetic material (DNA) and acts as the "control center" of the cell.
• Mitochondria: Known as the powerhouse of the cell, generating energy to fuel cellular processes.
• Ribosomes: These are responsible for protein synthesis and can be found floating in the cytoplasm or attached to the endoplasmic reticulum.

Understanding these structures can provide insight into how animal cells operate and why certain antibiotics can target bacterial cells without affecting animal cells.