Peptidoglycan

Definition

Peptidoglycan is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria. It provides structural support and protection.

5 Must Know Facts For Your Next Test

1. Peptidoglycan is a major component of the bacterial cell wall, especially in Gram-positive bacteria.
2. It consists of repeating units of N-acetylglucosamine (NAG) and N-acetylmuramic acid (NAM) linked by peptide chains.
3. Antibiotics like penicillin target peptidoglycan synthesis, leading to bacterial cell death.
4. The presence or absence of peptidoglycan can influence the effectiveness of certain immune responses.
5. Lysozyme, an enzyme found in tears and saliva, can break down peptidoglycan, contributing to innate immune defense.

Review Questions

• What are the main components of peptidoglycan?
• How do antibiotics like penicillin affect peptidoglycan?
• Why is peptidoglycan important for bacterial survival?

Related terms

Gram-positive Bacteria: Bacteria with thick peptidoglycan layers that retain crystal violet stain during Gram staining.

Antibiotics:

Drugs that target and kill or inhibit the growth of bacteria.

Lysozyme:

An enzyme that breaks down bacterial cell walls by cleaving peptidoglycan bonds.