Characteristics of Prokaryotes

Prokaryotes

Characteristics:

• Lack a true nucleus and membrane-bound organelles
• Typically small (0.5-5.0 μm) and simple in structure
• Cell wall peptidoglycan (also known as murein)
• Often have a single circular chromosome
• Reproduce by binary fission
• Examples: Bacteria (e.g., E. coli), Archaea (e.g., methanogens)

Types of Prokaryotes:

• Bacteria:
  • Gram-positive (thick peptidoglycan layer, e.g., Staphylococcus)
  • Gram-negative (thin peptidoglycan layer, e.g., E. coli)
• Archaea:
  • Methanogens (produce methane gas)
  • Thermophiles (thriving in high temperatures)
  • Halophiles (thriving in high salt concentrations)

Eukaryotes

Characteristics:

• Possess a true nucleus and membrane-bound organelles
• Typically larger (5-100 μm) and more complex in structure
• Linear chromosomes with histone proteins
• Reproduce by mitosis
• Examples: protozoa, fungi, plants, animals

Types of Eukaryotes:

• Protists:
  • Protozoa (e.g., Amoeba, Paramecium)
  • Algae (e.g., seaweed)
• Fungi:
  • Molds (e.g., Aspergillus)
  • Yeasts (e.g., Saccharomyces)
• Plants:
  • Bryophytes (e.g., mosses)
  • Vascular plants (e.g., trees)
• Animals:
  • Invertebrates (e.g., insects, worms)
  • Vertebrates (e.g., humans, fish)

Microbial World

Microbial Habitats:

• Soil microbiome
• Aquatic environments (e.g., oceans, lakes, rivers)
• Human microbiome (gut, skin, respiratory tract)
• Extreme environments (e.g., hot springs, deep-sea vents)

Microbial Interactions:

• Symbiotic relationships:
  • Mutualism (e.g., gut bacteria and host)
  • Commensalism (e.g., bacteria on skin)
  • Parasitism (e.g., pathogenic bacteria)
• Microbial communication:
  • Quorum sensing (cell-density dependent gene regulation)
  • Biofilm formation (complex microbial communities)

Prokaryotes

• Lack a true nucleus and membrane-bound organelles, making them simple in structure
• Typically small in size, ranging from 0.5-5.0 μm
• Cell wall is composed of peptidoglycan (also known as murein)
• Often have a single circular chromosome
• Reproduce by binary fission
• Examples of prokaryotes include Bacteria (e.g., E.coli) and Archaea (e.g., methanogens)

Types of Prokaryotes

• Bacteria:
  • Gram-positive bacteria have a thick peptidoglycan layer (e.g., Staphylococcus)
  • Gram-negative bacteria have a thin peptidoglycan layer (e.g., E.coli)
• Archaea:
  • Methanogens produce methane gas
  • Thermophiles thrive in high temperatures
  • Halophiles thrive in high salt concentrations

Eukaryotes

• Possess a true nucleus and membrane-bound organelles, making them more complex in structure
• Typically larger in size, ranging from 5-100 μm
• Have linear chromosomes with histone proteins
• Reproduce by mitosis
• Examples of eukaryotes include protozoa, fungi, plants, and animals

Types of Eukaryotes

• Protists:
  • Protozoa (e.g., Amoeba, Paramecium)
  • Algae (e.g., seaweed)
• Fungi:
  • Molds (e.g., Aspergillus)
  • Yeasts (e.g., Saccharomyces)
• Plants:
  • Bryophytes (e.g., mosses)
  • Vascular plants (e.g., trees)
• Animals:
  • Invertebrates (e.g., insects, worms)
  • Vertebrates (e.g., humans, fish)

Microbial World

• Microorganisms can be found in various habitats, including:
  • Soil microbiome
  • Aquatic environments (e.g., oceans, lakes, rivers)
  • Human microbiome (gut, skin, respiratory tract)
  • Extreme environments (e.g., hot springs, deep-sea vents)
• Microorganisms interact with each other and their environment through:
  • Symbiotic relationships, including mutualism, commensalism, and parasitism
  • Microbial communication, including quorum sensing and biofilm formation

Learn about the characteristics and types of prokaryotes, including their structure, reproduction, and examples. Explore the differences between Gram-positive and Gram-negative bacteria.