Lecture Notes: Microbial Life Sources

LO:

1. Understand that bacteria and archaea form two of the three domains of life
2. Understand that they are as genetically diverse from each other as they are from the eukarya
3. Understand that both groups are ubiquitous in the environment and have many different lifestyles and roles

Hard shit

• go back to powerpoint and look at dat table
• its on the major nutritional modes of bacterua. archaea and eukarya

Introduction

• Discuss three domains of life: Bacteria, Archaea, Eukarya
• Focus on bacteria and archaea in this lecture
• Explore how the different groups differ in terms of structure and function

Microbial History

Anthony van Leeuwenhoek

• Discovered the first microscopes used to observe microbes
• Made observations on various samples including water and dust

Early Ideas

• The idea that life arises from nothing (spontaneous generation)
• Francesco Redi and Louis Pasteur challenged this idea

Comparison between Bacteria, Archaea, and Eukarya

Cell Structure

• Eukarya: Organelles surrounded by membranes, nucleus
• Bacteria and Archaea: No nucleus, simpler structure

Genes and Chromosomes

• Bacteria and Archaea: Single circular chromosome, sometimes plasmids
• Eukarya: Linear chromosomes, genes split into introns and exons

Cell Membranes

• Bacteria: Ester linkages
• Archaea: Ether linkages

Genetic Processes

• Variety of introns in Archaea, less common in Bacteria

Role in Environment

• Microbes found everywhere, including extreme locations
• Archaea often in hydrothermal environments
• Bacteria responsible for important ecological processes such as nitrogen fixation

Microbial Groups and Their Functions

Bacteria

• Pathogens and disease-causing microbes
• Cyanobacteria associated with nitrogen fixation

Archaea

• No known human pathogens
• Associated with metabolic processes at different temperature levels

Geographic Importance

• Microbes are essential to Earth's ecosystems
• Producers of essential substances like vitamin B12

Conclusion

• Bacteria and archaea are essential to Earth's environments
• Their genetic and chemical differences make them unique
• Continue exploring their essential roles in ecological processes