Chapter 27 Flashcards
What are the 3 domains of life?
Bacteria
Archaea
Eukarya
What are the differences between Prokaryotes and Eukaryotes?
Eukaryotes are larger, more complex
they can be multicellular unlike prokaryotes
Eukaryotes have a nucleus and membrane bound organelles while prokaryotes have a nucleoid and no internal membranes
What domains do prokaryotes occupy?
Bacteria and Archaea
What are the three common shapes of bacteria?
Spheres; cocci- staphylococcus
rods; bacilli- lactobacillus
curves/spirals; vibrios, spirilla, spirochettes- vibrio cholerae
What are flagella?
A long cellular appendage specialized for locomotion
What are fimbriae?
A short, hairlike appendage of a prokaryotic cell that helps it adhere to the substrate or to other cells
What is a cell wall?
maintains shape and provides protection
What is lysis?
the disintegration of a cell by rupture of the cell wall or membrane.
What is a gram stain? Gram positive? Gram negative?
a staining technique for the preliminary identification of bacteria, in which a violet dye is applied, followed by a decolorizing agent and then a red dye. The cell walls of certain bacteria (denoted Gram-positive ) retain the first dye and appear violet, while those that lose it (denoted Gram-negative ) appear red
What is peptidoglycan?
Peptidoglycan, also known as murein, is a polymer consisting of sugars and amino acids that forms a mesh-like layer outside the plasma membrane of most bacteria, forming the cell wall
What are antibiotics?
Antibiotics or antibacterials are a type of antimicrobial used in the treatment and prevention of bacterial infection. They may either kill or inhibit the growth of bacteria
What is a capsule?
a gelatinous layer forming the outer surface of some bacterial cells.
What is a slime layer?
A slime layer in bacteria is an easily removable (e.g. by centrifugation), unorganized layer of extracellular material that surrounds bacteria cells.
What is biofilm?
A thin, slimy film of bacteria that forms. It can communicate by sending out signals that attract more bacteria, thus growing.
What are attachment pili?
fimbrae
What is taxis?
movement away from or towards stimulus.
positive taxis is towards stimulus and negative taxis is away from stimulus
What is chemotaxis?
A chemical stimulant is used
What is phototaxis?
A light stimulant is used
What is the circular ring of DNA in prokaryotes?
not surrounded by a nuclear membrane, located in a nucleoid region, fewer proteins associated with DNA, haploid
What are some examples of specialized membranes performing metabolic functions in prokaryotes?
cellular respiration
photosynthesis
What are plasmids?
Small rings of independently replicating DNA, provides antibiotic resistance in some R plasmids, can be transferred by conjugation
What are endospores?
Resistant, multilayered cells produced under adverse conditions like nutrient limitations or drought
What is binary fission?
During binary fission, the DNA molecule divides and forms two DNA molecules. Each molecule moves towards the opposite side of the bacterium. At the same time, the cell membrane divides to form 2 daughter cells (asexual)
What are the two types of autotroph?
photoautotrophs- use light as energy, use CO2 as carbon source (photosynthetic prokaryotes)
chemoautotrophs- use inorganic chemicals as energy, use CO2 as carbon source (unique to certain prokaryotes)
What are the two types of heterotrophs?
photoheterotroph- use light as energy, organic compounds as carbon source (unique to certain aquatic and salt-loving prokaryotes) chemoheterotroph-use organic compounds for energy and carbon source (many prokaryotes; fungi)
What are obligate aerobes?
prokaryotes that must use O2 for cellular respiration and cannot grow without it
What are obligate anaerobes?
prokaryotes that are poisoned by O2
What are falcultative anaerobes?
Prokaryotes that can use O2 in amounts and still use fermentation.
What are three kinds of Archaea extremophiles?
thermophiles, halophiles, and methanogens
What are thermophiles?
archaea that survive in very hot environments such as volcanic springs and hydrothermal vents
What are halophiles?
archaea that can survive in high saline environments like the Dead Sea and Great Salt Lake
What are methanogens?
archaea that produce CH4 as waste and live in places such as swamps, marshes, and vertebrate colons.
What are mutualistic bacteria?
Bacteria that form symbiotic relationships with the host. Both parties are benefitted. An example is Bioluminescence in anglerfish
What are pathogenic bacteria?
Bacteria that harm the host while they benefit. An example is Chlamydia
What are endotoxins?
Pathogenic bacteria.
part of the bacteria acts as the toxin, released when the bacteria die and cell wall breaks down. An example is Salmonella
What are exotoxins?
Pathogenic bacteria.
the toxin is secreted from the bacteria and can produce disease even when the bacteria is not present. An example is C. difficile
What is an example of Proteobacteria?
E. coli
What is an example of Chlamydias?
Chlamydia
What is an example of gram-positive bacteria?
Streptomyces
What is an example of cyanobacteria?
Oscillatoria
What is an example of spirochetes?
Leptospira
How do chemoheterotrophic prokaryotes function as decomposers?
They break down dead organisms as well as waste products, unlocking supplies of C, N, and other elements
What are some ecological interactions that prokaryotes perform?
Symbiosis which includes:
mutualism
commensalism
parasitism
What is mutualism?
both species benefit from the interaction
ex) bioluminescence in angler fish
What is commensalism?
One species benefits while the other is not harmed/benefitted
What is parasitism?
A parasite eats the cell tissue, fluids, or contents of the host
How do prokaryotes impact humans?
We have mutualistic bacteria and pathogenic bacteria
How do prokaryotes benefit technology and research?
bioremediation- removes pollutants from soil, air, or water
Bacteria in plastics such as PHA
biotechnology- E. coli used in gene cloning
