6.2 Archaea

Introduction

Archaea are a group of prokaryotic microorganisms that were initially classified as bacteria. However, molecular studies revealed that they are a distinct domain of life, separate from bacteria and eukaryotes. Archaea are known for their ability to survive in extreme environments, such as hot springs, salt lakes, and acidic environments. They have unique biochemical features that distinguish them from bacteria and eukaryotes.

Definition

Archaea: Archaea are prokaryotic microorganisms that were initially referred to as archaebacteria (derived from the Greek word "archaios," meaning ancient). These microorganisms are prokaryotic cells inhabiting extreme environments resembling conditions on early earth. Subsequent research has unveiled the distinctiveness of these unique microorganisms, leading to their classification within a separate domain known as Archaea.

In simple words: Archaea are ancient prokaryotes that live in extreme environments and are distinct from bacteria.

Core Concept

• Initially, the microorganisms known as Archaea were referred to as archaebacteria (derived from the Greek word "archaios," meaning ancient).
• These microorganisms are prokaryotic cells inhabiting extreme environments resembling conditions on early earth.
• Subsequent research has unveiled the distinctiveness of these unique microorganisms, leading to their classification within a separate domain known as Archaea.
• Archaea possess many unique features.
• They have special lipids in their membranes that help them live in extreme places like very hot or acidic environments.
• Unlike some other microbes, archaea do not have cell walls made of peptidoglycan.
• Some archaea can make methane, which is a type of gas.
• Many archaea can make their own food using hydrogen, sulfur, carbon dioxide, and water.
• Even though archaea seem similar to bacteria, they have different genetic and molecular traits, like their ribosomal RNA.