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35 Cards in this Set
- Front
- Back
virus
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-infectious particle consisting of a nucleic acid core surrounded by a protein coat (capsid)
-acellular |
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acellular
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-cannot independantly perform metabolic activities
-reproduce by taking over the reproductive machinery of other cells |
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origin of viruses
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originated from transposons or plasmids
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2 types of reproduction among viruses
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1- Lytic cycle
2- Lysogenic cycle |
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Lytic cycle
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-virus lyses the host cell
- 5 steps (1)Attatchment: phage attatches (2) Penetration: Phage DNA enters cell (3) Replication: phage DNA is replicated (4) Assembly: Phage components are assembled into mature viruses (5) Release: bacterial cell lyses and releases many phages |
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Lysogenic cycle
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-Temperate viruses don't destroy their hosts
(1)Attachment: phage attaches (2)Penetration: phage dna enters bacterial cell (3)Integration: phage dna integrates into bacterial dna (called "prophage") (4)Replication: the integrated prophage replicates when bacterial dna replicates |
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reverse transcriptase
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to transcribe the rna genome into a dna intermediate.
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viroid
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consists of a short strand that serves as a template copied by host rna polymerase
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prion
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proteinaceous infectious particle
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cocci
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spherical prokaryotes
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Bacilli
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rod-shaped prokaryotes
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spirochete
spirillum |
flexible
rigid spiral prokaryotes |
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Peptidoglycan
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eubacterial cell wall
consists of amino sugars linked with polypeptides |
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2 types of peptidoglycan walls
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gram-positive and gram-negative
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capsule
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slime layer that surronds the cell wall.
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pili
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hairlike appendages. help bacteria adhere to things.
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Asexual reproduction
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via binary fission
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binary fission
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one cell divides into 2 similar cells
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Sexual reproduction
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(1) transformation
(2) transduction (3) conjugation |
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Transformation
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fragments of DNA released by a cell are taken up by another bacterial cell
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Transduction
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a phage carries bacterial genes from one cell to another
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conjugation
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2 cells of different mating types come together and genetic material is transferred from one to the other
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Endospores
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when environment is unfavorable. cell becomes this.
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Heterotrophs
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obtain energy and carbon atoms from the organic compounds of other organisms.
Chemoheterotrophs & photoheterotrophs |
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Chemoheterotrophs
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(saprotrophs)
get their carbon and energy from dead organic matter |
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photoheterotrophs
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get their carbon from other organisms but use chloraphyll to trap energy from sunlight
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autotrophs
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manufacture their own food
photoautotrophs or chemoautotrophs |
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photoautotrophs
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use energy from sunlight to synthesize organic compounds from carbon dioxide
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chemoautotrophs
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obtain energy by oxidizing inorganic substances.
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facultative anaerobes
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use oxygen for cellular respiration. if O2 not available they respirate anaerobically
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obligate anaerobes
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carry on energy-yielding metabolism only without oxygen
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3 main types of Archaea
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methanogens
halophiles thermophiles |
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methanogens
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inhabit oxygen-free environments. strict anaerobes. produce methane gas from simple carbon compounds
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halophiles
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live in saturated brine solutions
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thermophiles
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live in hot, acidic environments
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