MicroBio

1. What is microbiology? Name the microbes that are studied in microbiology.

  • Microbiology is the study of microorganisms, which include bacteria, viruses, fungi, protozoa, and algae.

2. What is the difference between microbiology and molecular biology?

  • Microbiology focuses on microorganisms, while molecular biology studies molecular processes within cells, like DNA and protein synthesis.

3. What are the four major molecules (macromolecules) of life?

  • Carbohydrates, proteins, lipids, and nucleic acids.

4. Name and describe the twelve reasons why it is exciting to study microbiology.

  • Microbes are everywhere.

  • Microbes play a role in environmental processes.

  • Microbes are essential in biotechnology.

  • Microbes produce antibiotics.

  • Microbes help us understand human health.

  • Microbes are critical in agriculture.

  • Microbes help in energy production.

  • Microbes can be engineered for tasks.

  • Microbes have diverse metabolic pathways.

  • Microbes contribute to genetic diversity.

  • Microbes can cause diseases and are studied for treatment.

  • Microbes are small and easy to study.

5. What makes microbes ideal organisms for research?

  • They are small, reproduce quickly, and have simple structures, making them ideal for studying genetics, biochemistry, and cell biology.

6. What are the three fields of microbiology?

  • Bacteriology, virology, and mycology (fungal biology).

7. Understand the taxonomic conventions for naming organisms using the binomial nomenclature system.

  • Organisms are named using genus and species. Example: Escherichia coli (genus: Escherichia, species: coli).

8. What are the three domains of life and the characteristics of each?

  • Archaea: Prokaryotic, single-celled, extremophiles.

  • Bacteria: Prokaryotic, diverse, single-celled.

  • Eukarya: Eukaryotic, includes animals, plants, fungi, and protists.

9. What are the four kingdoms of the domain Eukarya and their characteristics?

  • Plants: Multicellular, photosynthesis, cellulose cell walls.

  • Fungi: Chitin cell walls, unicellular or multicellular.

  • Protists: Unicellular or multicellular, diverse.

  • Animals: Multicellular, heterotrophic, no cell walls.

10. Members of the domain archaea are mostly extremophiles. Are there any archaea known to cause disease in humans?

  • No, archaea are not known to cause disease in humans.

11. Why are helminths and arthropods studied in microbiology, even though they are not microscopic?

  • They play a role in diseases caused by parasitic worms and arthropods (e.g., mosquitoes).

12. What are some examples and features of fungi and protists?

  • Fungi: Yeasts, molds, mushrooms; cell walls made of chitin.

  • Protists: Amoeba, algae, and paramecium; diverse forms.

13. Why are viruses not included in the “tree of life?” In general, are viruses smaller or larger than bacteria?

  • Viruses are not considered living organisms and are smaller than bacteria.

14. What are the contributions of the 13 scientists that were fundamental to the development of microbiology?

  • Leeuwenhoek: First to observe bacteria.

  • Hooke: Coined the term "cell."

  • Redi: Disproved spontaneous generation.

  • Spallanzani: Proved that microbes come from the air.

  • Pasteur: Developed the germ theory and pasteurization.

  • Schleiden: Co-founder of cell theory for plants.

  • Schwann: Extended cell theory to animals.

  • Semmelweiss: Advocated handwashing.

  • Lister: Promoted antiseptic surgery.

  • Nightingale: Founder of modern nursing.

  • Koch: Developed Koch's postulates.

  • Jenner: Developed the smallpox vaccine.

  • Fleming: Discovered penicillin.

15. What is the concept of “Spontaneous Generation?” Describe the key experiments and scientists (3) that disproved “Spontaneous Generation.”

  • Spontaneous generation is the idea that life arises from non-living matter. Disproved by:

    • Redi: Meat jar experiment.

    • Spallanzani: Boiled broth experiment.

    • Pasteur: S-shaped flask experiment.

16. What is “Germ Theory?” Who proved “Germ Theory,” and what was the name of the opposing theory?

  • Germ theory states that microorganisms cause diseases. Proven by Louis Pasteur and Robert Koch, opposed by spontaneous generation.

17. What are some features that all cells have in common?

  • All cells have a plasma membrane, cytoplasm, ribosomes, and DNA.

18. Describe the function and composition of the plasma membrane, including the hydrophilic and hydrophobic regions of a phospholipid.

  • The plasma membrane is composed of a phospholipid bilayer with hydrophilic heads and hydrophobic tails, controlling the passage of substances into and out of the cell.

19. Compare and contrast prokaryotic and eukaryotic cells.

  • Prokaryotic cells: Lack a nucleus, smaller, simpler structures. Eukaryotic cells: Have a nucleus, more complex organelles.

20. Name and describe the three main shapes of bacteria.

  • Cocci (spherical).

  • Bacilli (rod-shaped).

  • Spirilla (spiral-shaped).

21. Name and describe the six main arrangements of bacteria.

  • Diplococci: Pairs of cocci.

  • Streptococci: Chains of cocci.

  • Staphylococci: Clusters of cocci.

  • Diplobacilli: Pairs of bacilli.

  • Streptobacilli: Chains of bacilli.

  • Palisades: Bacilli arranged in parallel.

22. How can you combine the shape (morphology) and arrangement of bacteria into one word?

  • By describing both the shape and arrangement (e.g., Streptococcus is a chain of spherical bacteria).

23. Compare and contrast Gram + and Gram - bacteria. What is the composition of their cell walls?

  • Gram +: Thick peptidoglycan, no outer membrane, sensitive to penicillin.

  • Gram -: Thin peptidoglycan, outer membrane, contains lipopolysaccharides.

24. Describe the structure of the cell wall of acid-fast bacteria. Name a genus of acid-fast bacteria. What diseases are caused by these types of bacteria? Why do acid-fast bacteria replicate slowly?

  • Acid-fast bacteria have a waxy lipid layer (mycolic acid). Example: Mycobacterium causes tuberculosis. Replication is slow due to the thick, resistant cell wall.

25. Draw, label, and define the internal structures of prokaryotic cells: cytoplasm, ribosomes (size?), chromosome, plasmid, and nucleoid.

  • Prokaryotic cells have cytoplasm, small ribosomes (70S), one circular chromosome, plasmids (small DNA pieces), and a nucleoid region.

26. Describe chromatophores and inclusion bodies of prokaryotes.

  • Chromatophores: Membrane-bound pigments for photosynthesis. Inclusion bodies: Store materials like lipids or starch.

27. What are endospores? How is an endospore different from a vegetative cell? What is their function, and which genera of bacteria make them? Differentiate between sporulation and germination.

  • Endospores are dormant, resistant forms of bacteria that survive extreme conditions. Genera: Bacillus and Clostridium. Sporulation is the formation of endospores, and germination is their return to a vegetative state.

28. What is the function of flagella? What are the terms that describe the number and attachment location of flagella?

  • Flagella aid in locomotion. Terms: monotrichous (one), lophotrichous (multiple at one end), amphitrichous (at both ends), and peritrichous (around the cell).

29. Describe run and tumble locomotion. Describe chemotaxis and phototaxis.

  • Run: Straight motion; tumble: Random motion. Chemotaxis: Movement toward or away from chemicals. Phototaxis: Movement toward or away from light.

30. Describe the function of pili. What are the two different types of pili?

  • Pili are involved in attachment and genetic exchange. Types: Fimbriae (attachment), sex pili (genetic exchange).

31. Define the terms capsule, slime layer, glycocalyx, and biofilm. What is the advantage of having a capsule?

  • Capsule: A thick, protective layer. Slime layer: A thin, slippery coating. Glycocalyx: Sugar coating around the cell. Biofilm: A community of microbes attached to a surface. Capsules protect against immune responses.

32. What is the difference between a nucleoid and a nucleus?

  • The nucleoid is the area in prokaryotes where DNA is located, while the nucleus is a membrane-bound organelle in eukaryotes that contains DNA.

33. How are eukaryotic chromosomes different from prokaryotic chromosomes?

  • Eukaryotic chromosomes are linear and found in a nucleus, while prokaryotic chromosomes are circular and located in the nucleoid region.

34. What are the functions of mitochondria and chloroplasts? How many lipid bilayers surround these organelles? Which organisms have chloroplasts? Do photosynthetic bacteria have chloroplasts?

  • Mitochondria produce ATP, and chloroplasts are involved in photosynthesis. Both have two lipid bilayers. Chloroplasts are in plants and algae, while photosynthetic bacteria lack chloroplasts.

35. Describe the endomembrane system, including the rough ER, smooth ER, Golgi apparatus, lysosomes, and vesicles. How are the processes of exocytosis and endocytosis related to these structures?

  • The endomembrane system includes organelles that work together to process and transport materials. Exocytosis and endocytosis involve vesicles for material transport.

36. Describe the function and the two locations of eukaryotic ribosomes.

  • Ribosomes produce proteins. They are found in the cytoplasm and attached to the rough ER.

37. What are the two functions of the cytoskeleton in eukaryotes? How are microtubules and motor proteins involved in these functions?

  • The cytoskeleton supports cell structure and helps with movement. Microtubules and motor proteins are involved in intracellular transport and cell division.

38. Do eukaryotes have cell walls? If so, which ones? Are they ever made of peptidoglycan?

  • Some eukaryotes have cell walls (e.g., plants, fungi) but they do not contain peptidoglycan.

39. What are three distinct ways that eukaryotic cells can move? Name an example of a microbe that moves through each of these means.

  • Cilia (e.g., Paramecium), 2) Flagella (e.g., Euglena), 3) Pseudopodia (e.g., Amoeba).

40. In your own words, what is the theory of endosymbiosis?

  • The theory of endosymbiosis suggests that mitochondria and chloroplasts were once free-living bacteria that were engulfed by a host cell.