Term
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Definition
All reproduce asexually
Binary fission - the genetic material of the cell is copied then Parent cell separates.
Snapping division - can lead to V-shapes, palisades
Reproductive structure formation - Budding |
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Term
| Arrangements of the Prokaryotic cells |
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Definition
Cocci - round shape
Bacilli - rod shape
Spirals - Spiral/ curvy shape
Diplo - cells in pairs
Tetrads - group of four
Strepto - In a form of a twisted chain
Staphylo - in cluster
Sarcina - cube formation
Palisades - weird angle
V- shapes
Pleomorphic bacteria (alter in response to the environment) vary in shape from one to the next |
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Term
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Definition
■ Produced by Gram-positive Bacillus and Clostridium
■ Constitute a defensive strategy against hostile or unfavorable conditions
■ Are not reproductive structures
■ Extremely resistant to drying, heat, radiation, and lethal chemicals
■ Stable resting stages
■ Can remain viable for tens to thousands of years
■ Serious concern to food processors, health care professionals, and governments |
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Term
| Modern Prokaryotic Classification |
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Definition
■ Archaea
■ Bacteria
■ Eukarya |
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Term
| Archaea (common features) |
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Definition
Lack peptidoglycan
Cell membrane lipids have branched hydrocarbon chains
Reproduce by binary fission, budding, or fragmentation
Most are cocci, bacilli, or spiral forms; unusual shapes exist
Not known to cause disease in humans or animals
Some are Extremophiles |
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Term
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Definition
■ Prominent members are thermophiles and halophiles
■ Thermophiles - DNA, RNA, cytoplasmic membranes, and proteins do not function properly below 45ºC (optimal 60 to 80 degrees)
■ Hyperthermophiles – require temperatures over 80ºC
■ Halophiles - Depend on greater than 9% NaCl to maintain integrity of cell walls (high concentrations of salt)
■ Methanogens - Convert carbon dioxide, hydrogen gas, and organic acids to methane gas
■ Convert organic wastes in pond, lake, and ocean sediments to methane
■ Some live in colons of animals; are one of primary sources of environmental methane |
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Term
| Deeply branching bacteria |
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Definition
| their rRNA sequences and growth characteristics lead scientist to conclude that these organisms are similar to the earliest bacteria; they seemed to have branched off from the "tree of life" |
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Term
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Definition
| acquire the energy needed for anabolism by absorbing light with pigment located in thylakoids called photosynthetic lamellae. also autotrophic |
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Term
| Low G+C Gram Positive Bacteria |
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Definition
| classified within phylum Firmicutes into three groups: clostridia, mycoplasmas and other low G+C Gram positive bacilli and cocci. |
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Term
| Gram-Negative Proteobacteria |
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Definition
Largest and most diverse group of bacteria
Five distinct classes:
Alphaproteobacteria - are typically aerobes capable of growing at very low nutrient levels.
Betaproteobacteria - same as alpha but different rRNA sequence
Gammaproteobacteria - largest and most diverse class of proteobacteria.
Deltaproteobacteria - not a large assemblage, but a wide variety of metabolic types.
Epsilonproteobacteria - rods, vibrios, or spirals. stomach. |
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Term
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Definition
Four major groups
● Protozoa
● Fungi
● Algae
● Water Molds and Slime Molds
● Include both human pathogens and organisms vital for human life |
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Term
| Reproduction in Eukaryotes |
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Definition
Many reproduce sexually by forming gametes (sexual cells) and zygotes (two gametes)
Algae, fungi, and some protozoa reproduce sexually and asexually |
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Term
|
Definition
Diverse group defined by three characteristics
- Eukaryotic
- unicellular
- Lack a cell wall |
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Term
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Definition
● Characterized by great morphologic diversity
● Some have two nuclei
● Macronucleus contains many copies of genome – controls metabolism, growth, and sexual reproduction
● Micronucleus – involved in genetic recombination, sexual reproduction, and regeneration of macronuclei
● All produce trophozoites (motile feeding stage); some produce cysts |
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Term
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Definition
Most are chemoheterotrophic
Obtain nutrients by phagocytizing bacteria, decaying organic matter, other protozoa, or the tissues of host |
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Term
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Definition
Most reproduce asexually only (binary fission or schizogony)
Few also have sexual reproduction |
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Term
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Definition
Study of fungi is called mycology
Chemoheterotrophic
Have cell walls typically composed of chitin
Lack chlorophyll; do not perform photosynthesis |
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Term
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Definition
Decompose dead organisms and recycle their nutrients
Form beneficial associations with roots of vascular plants that help plant absorb water and minerals
Produce antibiotics
30% cause diseases of plants, animals, and humans
Can spoil fruit, pickles, jams, and jellies (ascomycetes) |
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Term
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Definition
Acquire nutrients by absorption
Most are saprobes - nutrients from dead organisms. Some trap and kill microscopic soil-dwelling nematodes
Haustoria allow some to derive nutrients from living plants and animals
Most are aerobic (requires oxygen); some are anaerobic; many yeasts are facultative anaerobes |
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Term
| Budding and Asexual Spore Formation |
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Definition
Yeasts bud in manner similar to prokaryotic budding
Pseudohypha – series of buds that remain attached to one another and to parent cell
Filamentous fungi produce lightweight spores that differ in mode of development |
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Term
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Definition
● Cannot reproduce independently
● Obligate intracellular parasites
● Classified primarily by type of genome |
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Term
| Characteristics of Viruses |
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Definition
● Extracellular state called virion
● Protein coat (capsid) surrounding nucleic acid; provides recognition and protection
● Nucleic acid and capsid also called nucleocapsid
● Some have phospholipid envelope |
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Term
| Genetic Material of Viruses |
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Definition
● May be DNA or RNA; never both
● Can be dsDNA, ssDNA, dsRNA, ssRNA
● May be linear and composed of several segments or single and circular |
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Term
|
Definition
● Most only infect particular kinds of host’s cells
● May only infect particular kind of cell in host
● Generalists – infect many kinds of cells in many different hosts |
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Term
|
Definition
● Capsids – protein coats that provide protection for viral nucleic acid and means of attachment to host’s cells
● Capsid composed of proteinaceous subunits called capsomeres |
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Term
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Definition
| ● Envelope’s proteins and glycoproteins often play role in host recognition |
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Term
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Definition
● Dependent on host’s organelles and enzymes to produce new virions
● Replication cycle usually results in death and lysis of host cell → lytic replication
Stages of lytic replication cycle
● Attachment
● Entry (inside a cell, exists only as nucleic acid)
● Synthesis
● Assembly
● Release |
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Term
| Attachment of Animal Viruses |
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Definition
| ● Have glycoprotein spikes or other attachment molecules that mediate attachment |
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Term
| Assembly and Release of Animal Viruses |
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Definition
● Most DNA viruses assemble in and are released from nucleus into cytosol
● Most RNA viruses develop solely in cytoplasm |
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Term
| Assembly and Release of Animal Viruses |
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Definition
● Most DNA viruses assemble in and are released from nucleus into cytosol
● Most RNA viruses develop solely in cytoplasm |
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Term
| Latency of Animal Viruses |
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Definition
When animal viruses remain dormant in host cells
May be prolonged for years with no viral activity, signs, or symptoms |
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Term
| Characteristics of Prions |
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Definition
Proteinaceous infectious agents
Composed of single protein PrP
All mammals contain gene that codes for primary sequence of amino acids in PrP
Prion PrP converts cellular PrP into prion PrP by inducing conformational change |
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Term
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Definition
● All involve fatal neurological degeneration, deposition of fibrils in brain, and loss of brain matter
● Large vacuoles form in brain; characteristic spongy appearance
● Spongiform encephalopathies – BSE, CJD, kuru
Only destroyed by incineration or autoclaving in 1N NaOH |
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