Chapter 6 Flashcards
Marine Microbes
organisms too small to examine with the naked eye; including viruses, one-celled organisms, and fungi
Belong to three Domains
Eubacteria, Archaea, Eukarya
Virology
Viruses
Virology: study of viruses
Greater abundance than any other organism in the sea including:
Diversity
Significance in
marine food webs
3) Population biology
4) Disease
Viruses
Viruses
Many consider viruses non-living; bits of DNA & RNA surrounded by proteins; no metabolism
Viral Replication
Viruses
Rely on host cells for: energy, material, and organelles to duplicate
Virologists
Viruses
scientists who studies viruses
Two Hypotheses on origin:
Highly reduced prokaryotic cells
Renegade genes
Pathogens
a microbe that causes disease or mortality
Bacteriophage
Viruses
a virus that infects a bacterium; “phage – eater of bacteria”
Virion
Viruses
infective viral particle released by a host cell
Capsid
Viruses
Composed of nucleic acid core (DNA or RNA) surrounded by an outer protein coat
Nucleocapsid
Viruses
combined capsid and the core of nucleic acids of a virion
Envelope
Viruses
membrane derived from the hosts nuclear or cell membrane (coat)
Icosahedral
Viruses
Capsid with 20 triangular faces
Helical
Viruses
Capsid spirals around the core
Binal
Viruses
Icosahedral heads and helical tails
Lytic Cycle
Viruses
a virus has no dormant phase in the host before initiating viral replication
Lysogenic Cycle
Viruses
a virus remains dormant in the host cell awhile before initiating replication
Viral Abundance
Viruses
10^10 (10B) virons per Liter in surface waters
10^13 (10T) virons per Kg in sediment
Viral Population control
Viruses
Control plankton blooms
Alter Biogeochemical Cycles
Alter Food Webs
Causes Sedimentation of particles
Seston
Viruses
particles, living or dead, that are suspended in seawater
Value of Seston
Viruses
Viruses become adsorbed onto seston and rendered non-infective
Seston act like a charcoal filter; removing active viral material from the water column
Marine Bacteria
Bacteria
Belong to Domain Eubacteria and are:
Primary producers
Decomposers
Agents in Biogeochemical cycles
Food for Marine Inhabitants
Modifiers of Marine Sediments
Symbionts
Pathogens
Bacteria
Bacteria
Simple prokaryotic cells
- Lack nuclei and membrane-bound organelles
- Single chromosome of DNA
Reproduce asexually by
Binary Fission
Bacteria
one cell splits
into two after the original cell
has duplicated its genetic
material
Bacillus
Bacteria
Rod shaped bacteria
Coccus
Bacteria
Spherical bacteria
Spirillus
Bacteria
corkscrew shaped
Bacteria; rarest
Actinobacteria
Bacteria
fungi-like
bacteria found in marine
sediments
Autotrophs
Bacteria
Energy from sunlight
Chemoautotrophs
Bacteria
Energy from chemicals
Osmotrophy
Bacteria
type of heterotrophy where absorption of small organic molecules from the external medium across the cell membrane
Exoenzymes
Bacteria
enzyme released by osmotrophic microbes for external digestion
Cyanobacteria (blue-green bacteria/algae
Cyanobacteria
Photosynthetic prokaryotes that have chlorophyll a & b and release oxygen as a by-product of their photosynthesis
- store excess energy as cyanophycean starch single cells, colonies, or mats
Chlorophyll a
Cyanobacteria
the most common photosynthetic pigment of autotrophs; absorbs primarily violet and red light
Chlorophyll b
Cyanobacteria
a primary photosynthetic pigment found in few microbes, green algae, and all plants; absorbs primarily blue and red light
Carotenoids
Cyanobacteria
a class of accessory pigments that absorb blue light and protect chlorophylls from damage
Beta-carotene
Cyanobacteria
a yellow or orange carotenoid pigment
Xanthophylls
Cyanobacteria
a carotenoid pigment that confer a yellow or brown hue in some organisms
Phycobilins
Cyanobacteria
a class of accessory pigments that capture wavelengths less used by chlorophylls and transfer energy to them
Phycoerythrin
Cyanobacteria
a red phycobilin that absorbs green light
Phycocyanin
Cyanobacteria
a blue phycobilin that absorbs orange light
Mucilage
Cyanobacteria
gelatinous secretion of algal cells for attachment of cells and their protection
Stromatolite
Bacteria
a coral-like community of microbes that form a thin layer of living cells and filaments over an accumulated mass of dead stony material
Obligate Anaerobes
Archaea
thrives only in absence of oxygen (e.g. Sulfur bacteria)
Facultative Anaerobe
Archaea
thrives in the presence or absence of oxygen; photosynthesize in presence of light (e.g. Nonsulfur bacteria)
Bacteriophylls
Archaea
a class of primary photosynthetic pigments that do not release O2
Chemosynthetic Bacteria
Archaea
can form organic molecules from inorganic molecules using other chemicals rather than sunlight as a source of energy
Heterotrophic Bacteria
Bacteria
decomposers; use surrounding organic matter for materials and energy - release exoenzymes to digest natural molecules resistant to decay (e.g. cellulose)
Consolidation
Bacteria
the aggregation of suspended particles in seawater by bacteria
Lithification
Bacteria
the conversion of consolidated particles into a solid mass with mineral cement
Sedimentation
Bacteria
the settlement of water particles from suspension in water
Nitrogen Fixation
Bacteria
conversion of atmospheric nitrogen into ammonium ion
Nitrogenase
Bacteria
an enzyme used to “fix” nitrogen by breaking the strong molecular bond between atoms of nitrogen is the molecule of nitrogen gas; takes place in the
Heterocyst
Cyanobacteria
specialized cell in which conditions favorable for nitrogen fixation are maintained
-in cyanobacteria
Symbiotic Bacteria
Endosymbiosis
Many bacteria have evolved symbiotic relationships with other marine organisms
Endosymbiotic Theory:
Endosymbiosis
the body of evidence supporting the idea that some one-celled organisms have evolved by the incorporation of other one-celled organisms or their organelles into the host cell (e.g. – plastids, mitochondria, hydrogenosomes
Eukarya
Endosymbiosis
domain that contains all organisms with eukaryotic cells (plants, animals, fungi)
Phagocytosis
a cell engulfs a particle by inwardly folding and separation of the cell membrane to form a vacuole
Plastids
Endosymbiosis
: an organelle in eukaryotic cell derived originally by endosymbiosis with a cyanobacterium (e.g. – chloroplasts)
Endosymbiont
Endosymbiosis
guest organism or organelle that lives within a host organism or cell
Hydrogen Hypothesis
Endosymbiosis
a concept on the origin of eukaryotic cells that postulates an endosymbiotic relationship between a host archaeon that needed hydrogen for chemosynthesis and a guest bacterium that released hydrogen and became a mitochondrion
Plastid Endosymbiosis
Endosymbiosis
evolutionary process by which a heterotrophic host cell gains the ability to photosynthesize from a photoautotrophic guest cell
Deep-sea Vent community
Archaea
a community of marine organisms that depend upon the specialized environment found at divergence zones in the ocean floor
Chemosynthetic Bacteria
Archaea
can form organic molecules from inorganic molecules using other chemicals rather than sunlight as a source of energy
Bioluminescent Bacteria
Bacteria
capable of emitting blue-green or yellow light using chemical energy
Photophores
Bacteria
an organ in some organisms that produces bioluminescence; contain cultures of luminescent bacteria
Archaea
Archaea
Domain that contains Archaeons which were formerly considered to be bacteria
Archaeons
Archaea
differ from bacteria in the biochemistry, genetic makeup, ability to produce methane, and tolerance of extreme environmental conditions
Three basic types or Archaeons
Archaea
Methanogens, Halobacteria, Hyperthermophiles
Methanogen
Archaea
an archaeon that produces methane in its metabolism; are chemosynthetic and use hydrogen for energy
Halobacteria
Archaea
an archaeon that require high concentrations of salt where they live; are
Halophiles
Archaea
an organism grows and reproduces best in the presence of salt
Bacteriorhodopsins (purple proteins)
Archaea
light-capturing protein that produces ATP in halobacteria
Hyperthermophiles
Archaea
a microbe that grows and reproduces best at temperatures exceeding 100°C; live in deep-sea hydrothermal hot vents
Chemosynthetic
Archaea
uses carbon dioxide and hydrogen to produce organic compounds
Eukarya
Eukarya
domain that contains all organisms with eukaryotic cells (plants, animals, fungi)
Phagocytosis
Eukarya
a cell engulfs a particle by inwardly folding and separation of the cell membrane to form a vacuole
Fungi
Fungi
<1% of known species are marine
Mycologist
Fungi
scientist who studies fungi
Mycology
Fungi
the study of fungi
Aspergillosis
Fungi
a fungal disease caused by genus Aspergillus
Yeast
Fungi
single-celled fungus
Filamentous fungus
Fungi
consists of long thread-like masses called Hypha which produce a tangled mass
Mycelium
Fungi
body of a fungus
Budding
Fungi
asexual reproduction in which two individuals are produced by unequal division of the adult
Conidiospore
Fungi
an asexually produced dispersal stage in the life cycle of a fungus
Fruiting body
Fungi
a sexually reproductive structure of a fungus
Ascocarp
Fungi
the fruiting body of an ascomycote fungus
Ascus
Fungi
one component of an ascocarp that produces 4 to 8 spores
Lichens
Fungi
mutualistic associations between a fungus and an algae
Fungus: ascomycotes Algae: green algae
Stramenopiles
Stramenopiles
a group of organisms that includes diatoms and have specialized flagella
Mastigonemes
Stramenopiles
Hair-like filaments that
extend from the shaft
of some flagella
Ochrophytes
Stramenopiles
photosynthetic stramenopiles; store energy as a specialized starch called
Laminarin
Secondary plastid endosymbiosis
Endosymbiosis
the condition in which an ancestor became host to a red algal cell that became the hosts plastid
Diatoms
Diatoms-Stramenopiles
one of the most distinctive marine phytoplankton;>45% ocean primary production
Frustule
Diatoms
two-part cell wall of a diatom
Valve
Diatoms
is one part of the diatom frustule
Centric Diatom
Diatoms
has radially symmetrical valves; pelagic
Pennate Diatom
Diatoms
has bilaterally symmetrical valves; benthic
Raphe
Diatoms
slit along the valve by which some pennate diatoms move along surfaces. Pennate diatoms secrete mucilage through it.
Silicoflagellates
Stramenopiles
are planktonic marine plankton that are both photosynthetic and heterotrophic
Internal silica skeletons are composed of a network of bars; propel themselves with one long eukaryotic flagellum, or Undulipodium
Labyrinthomorphs
Stramenopiles
heterotrophic stramenopiles that are decomposers and pathogens
Haptophytes
Haptophytes
a group of eukaryotic microbes that possess a Haptonema
Haptonema
Haptophytes
a rod-like organelle that projects between the two flagella of haptophytes and is used to capture prey (Coccolithophores)
Coccolithophores
Haptophytes
photosynthetic haptophytes with the cell surface covered by calcareous scales called Coccoliths
Alveolates
Alveolates
a group of microbes with membranous sacs (Alveoli) beneath the cell membrane; include dinoflagellates and cilliates
Pellicle
Alveolates
the complex of alveoli and the cell membrane in alveolates
Dinoflagellates
Alveolates-Dinoflagellates
an alveolate with cellulose in its alveoli and with two heterokont flagella for locomotion
90% are marine: planktonic and benthic, some symbiotic, parasitic, zooxanthelle and bioluminescent
Dominate warm-temperate waters
Dinosporin
Dinoflagellates
a decay-resistant
chemical in the cellulose
of dinoflagellates
Cingulum
Dinoflagellates
horizontal groove in the middle of a dinoflagellate; contains shorter flagellum
Sulcus
Dinoflagellates
the longitudinal groove on the surface of a dinoflagellate that extends from the cingulum; contains longer flagellum
Unarmored/Naked dinoflagellate (Athecate)
Dinoflagellates
has a few thin layers of cellulose in its alveoli; giving the appearance of having no protective cell covering
Armored dinoflagellate (Thecate)
Dinoflagellates
has many layers of cellulose in its alveoli giving the appearance of having a protective cell covering
Phagotrophy
Eukarya
a mode of nutrition by which one organism eats another either by phagocytosis or by taking into the mouth
Ciliates
Cilliates
a group of alveolates that use cilia for locomotion and feeding
Membranelles
Cilliates
ribbon-shaped or tufted arrangements of cilia that increase the effectiveness of locomotion and feeding
Cytostome
Ciliates
organelle in a ciliate where phagocytosis occurs
Lorica
Ciliates
: loosely fitting
external covering
Micronucleus
Ciliates
smaller nucleus of a ciliate, holds one set of chromosomes for inheritance by the next generation
Macronucleus
Ciliates
larger nucleus of a ciliate, holds many sets of chromosomes, and plays a role in metabolism of the cell
Conjugation
Ciliates
sexual reproduction that involves the exchange of nuclei between fused cells
Choanoflagellates
Choanoflagellates
a group of microbes that filter suspended particles through a specialized collar surrounding the flagellum (sponge cells)
Microvillus
Choanoflagellates
one of many short, hair-like extensions that form the collar of choanoflagellates
Amoeboid Protozoans
Amoeboid Protozoans
a group of microbes characterized by a Pseudopod
Pseudopod
Amoeboid Protozoans
a finger-like projection of cytoplasm and membrane that functions in both locomotion and feeding in amoeboid protozoans
Test
Amoeboid Protozoans
external
skeleton of an
amoeboid
protozoan
Foraminiferan
Amoeboid Protozoans-Foraminiferans
is an amoeboid marine protozoan with specialized pseudopods and a calcareous test
Reticulopod
Amoeboid Protozoans-Foraminiferans
a pseudopod of foraminiferans with branches that interconnect to form a net for the capture of particles
Radiolarians
Amoeboid Protozoans-Radiolarians
an amoeboid marine protozoan with specialized, needle-like pseudopods (Actinopods) and a skeleton of silica
Capsule
Amoeboid Protozoans-Radiolarians
an external organic layer in radiolarians that separates the inner
nuclear region from the outer region
Calymma
Amoeboid Protozoans-Radiolarians
vacuolated outermost
cytoplasm of a radiolarian; formed
by actinopods passing through
the capsule
