What type of membrane surrounds Gram-negative bacteria?

What type of membrane surrounds Gram-negative bacteria?

• A. Single-layer membrane
• B. Peptidoglycan membrane
• C. Outer membrane surrounding an inner membrane
• D. Cellulose membrane

Answer: (C)

Gram-negative bacteria are characterized by having a unique cell envelope structure which consists of an outer membrane and an inner membrane. This dual-membrane system is a defining feature of Gram-negative bacteria and plays a critical role in their physiology and interactions with their environment. The outer membrane is composed of a lipid bilayer that contains lipopolysaccharides (LPS), which are important for maintaining the structural integrity of the bacteria and for protection against certain antibiotics and detergents. Beneath the outer membrane lies the periplasmic space, which contains a thin layer of peptidoglycan, as well as various proteins and enzymes that contribute to nutrient transport and metabolic processes. The inner membrane, or cytoplasmic membrane, is similar to that found in all bacterial cells. It serves as a barrier to the cytoplasm and is involved in processes such as energy production and transport of molecules into and out of the cell. In contrast, other membrane types mentioned in the choices, such as a single-layer membrane or cellulose membrane, do not accurately represent the structure of Gram-negative bacteria. Additionally, while peptidoglycan does form part of the cell wall structure, it is not a membrane itself and is primarily located in the periplasmic space.

Gram-negative bacteria are characterized by having a unique cell envelope structure which consists of an outer membrane and an inner membrane. This dual-membrane system is a defining feature of Gram-negative bacteria and plays a critical role in their physiology and interactions with their environment.

The outer membrane is composed of a lipid bilayer that contains lipopolysaccharides (LPS), which are important for maintaining the structural integrity of the bacteria and for protection against certain antibiotics and detergents. Beneath the outer membrane lies the periplasmic space, which contains a thin layer of peptidoglycan, as well as various proteins and enzymes that contribute to nutrient transport and metabolic processes.

The inner membrane, or cytoplasmic membrane, is similar to that found in all bacterial cells. It serves as a barrier to the cytoplasm and is involved in processes such as energy production and transport of molecules into and out of the cell.

In contrast, other membrane types mentioned in the choices, such as a single-layer membrane or cellulose membrane, do not accurately represent the structure of Gram-negative bacteria. Additionally, while peptidoglycan does form part of the cell wall structure, it is not a membrane itself and is primarily located in the periplasmic space.