CHAPTER 1 STUDY GUIDE PDF

1. Define Microbiology: Microbiology is the study of microorganisms, including bacteria, viruses, fungi, protozoa, and algae. These microorganisms are often too small to be seen with the naked eye, and microbiology focuses on their role in diseases, environmental process...

1. Define Microbiology: Microbiology is the study of microorganisms, including bacteria, viruses, fungi, protozoa, and algae. These microorganisms are often too small to be seen with the naked eye, and microbiology focuses on their role in diseases, environmental processes, and industrial applications. 2. Name the 3 domains in taxonomy and list the characteristics of each: Bacteria: o Prokaryotic (no nucleus). o Single-celled organisms. o Cell walls contain peptidoglycan. o Found in many environments (soil, water, human body). Archaea: o Prokaryotic (no nucleus). o Single-celled organisms. o Cell walls do not contain peptidoglycan instead they have pseudomurein. o Live in extreme environments (hot springs, salt lakes). Eukarya: o Eukaryotic (cells have a nucleus). o Includes organisms like animals, plants, fungi, and protists. o More complex cell structure with organelles like mitochondria and chloroplasts. 3. Know the 7 specific groups of life and the general characteristics of each (6 organisms and viruses): Bacteria: Single-celled, prokaryotic, found almost everywhere. Archaea: Prokaryotic, live in extreme conditions, no peptidoglycan. Fungi: Eukaryotic, decomposers, including molds, and yeasts. Protozoa: Eukaryotic, single-celled, often mobile, found in water and soil. Algae: Eukaryotic, photosynthetic, found in water, can be single-celled or multicellular. Helminths: Multicellular parasitic worms, such as tapeworms and roundworms. Viruses: Non-living, composed of genetic material (DNA or RNA) and a protein coat, replicate inside host cells. 4. Know the benefits and importance of microorganisms to us and all other life - examples: Food production: Microorganisms like yeast help in the production of bread, beer, and wine. Decomposition: Bacteria and fungi break down dead organic material, recycling nutrients. Nitrogen fixation: Some bacteria convert nitrogen from the air into a form plants can use. Biotechnology: Bacteria are used to produce insulin, antibiotics, and other medicines. Digestive health: Gut bacteria help humans and animals digest food and produce vitamins. 5. Know what a pathogen is and the two types of pathogens: A pathogen is a microorganism that can cause disease. o Primary pathogen: Can cause disease in a healthy host (e.g., Mycobacterium tuberculosis). o Opportunistic pathogen: Causes disease only when the host’s defenses are compromised (e.g., Candida albicans in immunocompromised individuals). 6. Define a microbe, microbiology, and differentiate the major types of microorganisms: Microbe: A microorganism, especially a bacterium, virus, or fungus. Microbiology: The study of microbes and their interactions with humans, animals, plants, and the environment. Major types of microorganisms:  o Bacteria: Prokaryotic, single-celled. o Archaea: Prokaryotic, single-celled, often extremophiles. o Fungi: Eukaryotic, can be single-celled (yeasts) or multicellular (molds). o Protozoa: Eukaryotic, single-celled, often motile. o Algae: Eukaryotic, photosynthetic. o Viruses: Non-living, require a host cell to replicate. 7. Compare and contrast prokaryotic vs. eukaryotic cells: Prokaryotic cells: o No nucleus and lack of membrane-bound organelles. o Smaller, simpler structure. o One circular chromosome. o Divides by binary fission Eukaryotic cells: o Have a nucleus and organelles. o Larger and more complex. o Paired chromosomes (histones- protein DNA “wraps around”) o Divides by mitosis 8. Compare and contrast bacteria vs. archaea: Bacteria: o Have peptidoglycan in their cell walls. o Environmentally important as decomposers by breaking down dead organic matter into simpler substances. Nitrogen-fixing bacteria convert atmospheric nitrogen to form nitrogen that plants can absorb and use to grow. Photosynthetic bacteria convert light energy into chemical energy. o Source of antibiotics together with fungi. Archaea: o Have pseudomurein in their cell walls. o Often live in extreme environments (extremophiles). o Non-pathogenic Both are prokaryotic and lack a nucleus, but they have different cell wall structures and environmental preferences. 9. Describe the endosymbiotic theory: The endosymbiotic theory suggests that eukaryotic cells evolved when one prokaryotic cell engulfed another, forming a symbiotic relationship. Over time, the engulfed cell became a permanent part of the host cell, evolving into organelles like mitochondria and chloroplasts. This explains why these organelles like mitochondria have their DNA and resemble prokaryotic cells and chloroplasts, the photosynthetic organelles in plants and algae are believed to have originated from cyanobacteria. 10. Compare and contrast Protista - algae and protozoa; who evolved from each? Algae: o Photosynthetic, produce oxygen. o Can be unicellular-celled or multicellular. o Contains cellulose or silica as their cell wall. Protozoa: o Heterotrophic, usually mobile. o Single-celled (unicellular). o No cell wall. Both are part of the Protista group, but they differ in their methods of nutrition and reproduction. 11. Describe a virus; where do they fit into the tree of life? A virus is a small, non-living particle made of genetic material (DNA or RNA) encased in a protein coat. Viruses cannot replicate on their own; they must infect a host cell to reproduce. Viruses are not considered living organisms, so they do not fit into the tree of life. Instead, they exist outside the traditional classification system. 12. Explain the significance of DNA for determining the traits of life: DNA carries the genetic information for all living organisms. It encodes the instructions for making proteins, which determine an organism’s traits (e.g., eye color, blood type, enzyme activity). DNA replication ensures that genetic information is passed from one generation to 13. Protist the 1st Eukaryotes the evolutionary split from prokaryotes