Chapter 1: Humans and the Microbial World Flashcards
What are the three major groups of microorganisms?
- prokaryotes
- eukaryotes
- acellular microbes
What are prokaryotes? (2)
- bacteria (and archaea)
- have one single xme
What are eukaryotes?
- Algae
- Fungi
- Protozoa
What are acellular microbes?
- Viruses (DNA and RNA types)
Order the following from smallest to largest: virus, bacteria, microeukaryotes
- viruses
- bacteria
- microeukaryotes (protozoa)
Viruses are very small. What size?
20 nm (0.000002 mm)
Some protozoa (Eukaryotes) are very large. What size?
- 5 mm
The best studied microorganism is bacteria. What is their size?
- 1 micrometer, or 0.001 mm
What are the major entities living in the biosphere?
- VIRUSES
Why are microbes important to the environment? (4)
- some produce oxygen
- Fix nitrogen for use by plants
- important members of the food chain
- breakdown and recycle organic wastes
Why are microbes important for industries?
- used by industry to produce beer, wine, pickles, cheese, etc.
- pharmaceuticals use it to make antibiotics
- genetically engineered to produce therapeutic substances like insulin
- Play a role in human immunity - normal microbiota
How can microbes degrade explosives?
- Trinitrotoluene, or TNT, contaminates the soil in areas where ammunition is kept
- Bacteria named Clostridium bifermentans can break down this contaminant
What is bioremediation? (2)
- the biological degrading processes for the treatment of contaminated soils, groundwater, or sediments
- relies of microorganisms like bacteria and/or fungi to use the contaminants as a food source to degrade the contaminant
essentially using microbes to degrade organic pollutants
Why is bioremediation beneficial?
- the most economic remedial techniques for treating most organic fuel based contaminants like coal tars, petroleum, etc.
How can bacteria help with oil spills? (5)
- natural microbes in the ocean feed on hydrocarbons in oil
- oil contains hydrocarbons (made of H and C)
- oxygen is needed for the reaction, but can be sparse at great ocean depths
- so the microbes break apart the hydrocarbons and combine them with oxygen to create water and CO2
- not all of the oil can be consumed, but the leftovers can be easily dispersed by currents and wind
Why is adding fertilizer not good for helping bacteria clean up oil spills? (2)
- fertilizer increases the size and number of microbes so they can eat more oil
- too much fertilizer can cause algae blooms that starve the ecosystem of light and oxygen
How are bacteria used to make chocolate? (3)
- chocolate comes from the seeds of the cacao tree
- the seeds come in pods and the only way to retrieve the seeds are to ferment them with yeasts and lactobacilli and acetobacter
- The lactobacillus secretes an acid to help break apart the pod
How can microbes make plastics? (2)
- Alcaligenes eutrophus is a useful bacterium that makes plastics
- strong hopes of using these bacteria and their plastics for medical purposes
How can bacteria fade jeans? (2)
- Alkalothermophilic Thermomonospora produces enzyme cellulase
- when you mix cellulase with denim cloth, it reduces the hairiness and makes it softer and lighter
How can bacteria act as insecticides? (2)
- used and studied as biocontrol agents to help control diseases in important crops
- can control pests
