Microbes (1) Flashcards
What happens when your microbial communities are disrupted?
-Increase our susceptibility to infectious diseases
-Contribute to conditions such as asthma and other allergies, irritable bowel syndrome, Crohn’s disease, and autism.
Differentiate between prokaryotes and eukaryotes.
-Prokaryotic cells are smaller than eukaryotic cells.
-The collective biological mass (biomass) of prokaryotes is at least 10 times that of all eukaryotes. (there are more prokaryotes than eukaryotes)
-Prokaryotes exhibit much more nutritional diversity than eukaryotes. This allows them to inhabit almost every nook and cranny on Earth.
What are the two kinds of prokaryotes?
There are two very different kinds of prokaryotes, classified in the domains Archaea and Bacteria.
What are the types of prokaryotic cell shape?
Three of the most common prokaryotic cell shapes are the following:
- Spherical prokaryotic cells called cocci
- Rod-shaped prokaryotes called bacilli
- Spiral prokaryotes of two types:
-Relatively short and rigid cells called spirilla
-Longer and more flexible cells called spirochetes.
How can prokaryotes be classified by gram stain?
-Gram-positive bacteria have simpler walls with a relatively thick layer of a unique material called peptidoglycan.(which helped evolutionary success of prokaryotes)
-The walls of gram-negative bacteria stain differently.
Describe the sticky capsule in prokaryotes and its function.
Capsules are sticky, protein and sugar coated membranes that surround the bacterial cell wall and can help bacteria stick to surfaces and shield them from the host immune system
What is the function of the flagella in prokaryotes?
Flagella enable bacteria to move in the director of food or chemical stimuli in their environment
What is the role of the fimbrae?
Fimbrae also help with surface attachment and colony formation
What are endospores?
Endospores are specialized resistant cells that form inside the original cell and produce the chromosome surrounded by a protective coat.
Prokaryotes form endospores that remain dormant through harsh conditions.
How do endospores persist through harsh conditions?
After the endospore is dehydrated, which stops its metabolism, the original cell disintegrates. When an endospore receives environmental cues that conditions have improved, it absorbs water and resumes growth.
What are the 2 sources of energy used by prokaryotes?
Two sources of energy can be used by prokaryotes:
-Like plants, prokaryotic phototrophs capture energy from sunlight.
-Prokaryotes called chemotrophs harness the energy stored in chemicals
What are the energy sources and carbon sources of the following:-
- Photoautotroph
- Chemoautotroph
- Photoheterotroph
- Chemoheterotroph
- Sunlight; CO2
- Inorganic chemicals; CO2
- Sunlgiht; Organic compounds
- Organic compound; organic compounds.
What are biofilms?
Prokaryotes attach to surfaces and form highly organized biofilm communities that are difficult to eradicate, causing both medical and environmental problems.
What is bioremediation?
Bioremediation is the use of organisms to remove pollutants from soil, air, or water.
Prokaryotes are often used for bioremediation, including in sewage treatment facilities.
Advances in molecular genetics revealed that many prokaryotes are more closely related to eukaryotes than to other prokaryotes. What were the hypotheses made based on this?
-The first major split in the history of life was the divergence of bacteria
-A later divergence separated the domains Archaea and Eukarya.
