Question

Given below are two statements:
Statement (I): Bovine milk contains more lysozyme content than that of human milk.
Statement (II): Gram negative bacteria are more sensitive to lysozyme than gram positive bacteria due to the absence of peptidoglycan component in the cell wall.
In light of the above statements, choose the most appropriate answer from the options given below.

• A. Both Statement (I) and Statement (II) are true
• B. Both Statement (I) and Statement (II) are false
• C. Statement (I) is true but Statement (II) is false
• D. Statement (I) is false but Statement (II) is true

Hint:

Remember:
- Lysozyme levels: Human milk \(\gg\) Bovine milk.
- Susceptibility: Gram-positive bacteria are highly sensitive to lysozyme, while Gram-negative bacteria are resistant due to their outer membrane barrier.

Answer 1

The Correct Option is B

Step 1: Understanding the Concept:
Lysozyme is an antimicrobial enzyme naturally present in various biological secretions, including milk, tears, and saliva.
It serves as a primary non-specific defense mechanism against bacterial infections by targeting structural components of the bacterial cell wall.

Step 2: Detailed Explanation:
Let us analyze both statements:
-Statement (I): "Bovine milk contains more lysozyme content than that of human milk."
This statement is incorrect.
Human milk contains a high concentration of lysozyme, typically ranging from 300 to 400 mg/L.
In contrast, bovine milk contains only trace amounts of lysozyme, averaging between 0.05 and 0.13 mg/L.
Therefore, human milk contains thousands of times more lysozyme than bovine milk.
-Statement (II): "Gram negative bacteria are more sensitive to lysozyme than gram positive bacteria due to the absence of peptidoglycan component in the cell wall."
This statement is incorrect.
Lysozyme targets and hydrolyzes the \(\beta(1\rightarrow4)\) glycosidic bonds between N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) in the peptidoglycan layer of the cell wall.
Gram-positive bacteria have a thick, exposed peptidoglycan layer as their outermost cell wall component, making them highly sensitive to lysozyme.
Gram-negative bacteria possess a thin peptidoglycan layer, but it is shielded by an outer lipopolysaccharide membrane.
This outer membrane prevents lysozyme from reaching the peptidoglycan layer, making Gram-negative bacteria highly resistant to the enzyme unless their outer membrane is disrupted.
Additionally, Gram-negative bacteria do have a peptidoglycan layer; it is not absent.
Thus, both Statement (I) and Statement (II) are false.

Step 3: Final Answer:
Both Statement (I) and Statement (II) are false, which corresponds to Option (B).