Module 2 Test Flashcards
Chapters 4, 5, and 6
Basic cell shapes
Spherical, cubical, cylindrical
Internal contents of cells
Cytoplasm surrounded by a membrane
Eukaryotic cells
Includes animals, plants, fungi, and protists
-Membrane-bound organelles
-Double membrane bound nucleus
Prokaryotic cells
Includes bacteria and archaea
-No nucleus or membrane bound organelles
-Smaller and less complex
Characteristics of life
-Reproduction and heredity
-Growth and development
-Metabolism
-Movement and/or irritability
-Cell support, protection, and storage
-Transport of nutrients and waste
Prokaryotes: Appendages for motility
Flagella and axial filament (periplasmic flagella)
Prokaryotes: Appendages for attachment or channels
Fimbrae and pili
What composes a flagella?
Filament- long, thin, helical structure composed of flagellin
Hook- curved sheath
Basal body- stack of rings firmly anchored in cell wall
Monotrichous flagella
single flagellum at end
Lophotrichous flagella
Small bunches emerging from the same site
Amphitricous flagella
Rare flagella at both ends of cell
Peritrichous flagella
flagella dispersed all over surface of cellP
Phototaxis
light stimuli
Chemotaxis
Chemical stimuli
+ vs - taxis
+=toward/attracted to
-= away/deterred from
Motion in flagella
Counterclockwise- run
Clockwise- tumble
Periplasmic flagella
-Internal flagella enclosed in the space between the outer sheath and cell wall (peptidoglycan)
How do periplasmic flagella produce motility?
By contracting and imparting twisting or flexing motions
Prokaryotes: Fimbriae
Fine, proteinaceous, hairlike bristles emerging from cell surface
Fimbriae Function
Function in adhesion to other cells and surfaces
Prokaryotes: Pili
Rigid, tubular structure made of pilin
Gram-negative cells only
Function of pili
Function to join cells for partial DNA transfer
Conjugation
DNA transfer– send genetic material via channel
Prokaryotes: Glycocalyx
Coating of molecules external to cell wall made of sugars and/or proteins
Prokaryotes: Types of glycocalyx
Slime layer- loosely organized and attached– function in attachment
Capsule- highly organized, tightly attached– function in protectionF
Prokaryotes: Functions of the glycocalyx
-Protect cells from dehydration and nutrient loss
-Inhibit killing by wbc by phagocytosis
-Attachment- formation of biofilms
Prokaryotes: Cell Envelope
-External covering outside cytoplasm (cell wall and cell membrane)
-Maintains cell integrity
Gram-positive bacteria
-Thick cell wall composed primarily of peptidoglycan and cell membrane
-Retain crystal violet, stain purple
Gram-negative bacteria
-Two cell membranes with a small layer of peptidoglycan in between
-Retain safranin, stain red/pink
-More difficult to penetrate (harder to kill)
Chemical components of gram-positive bacteria cell wall
Techoic acid and lipoteichoic acid- function in cell wall maintenance and enlargement during cell division
Chemical components of gram-negative bacteria cell wall
Lipopolysaccharides in the outer membrane- function as receptors to block immune response
-Contain porin proteins in upper layer- regulate molecules entering and leaving cell
Nontypical cell wall of mycobacterium and nocardia
-Gram-positive cell wall structure with lipid mycolic acid
-Pathogenicity and high degree of resistance to certain chemicals and dyes
-Acid-fast stain used for diagnosis
Mycoplasma Cell wall
-No cell wall
Prokaryotes: Cell membrane structure
-Phospholipid bilayer with embedded proteins
-Semipermeable
Functions of phospholipid bilayer
-Energy reactions, nutrient processing, and synthesis
-Passage of nutrients in and discharge of waste
Cytoplasm
70-80% water- solvent for materials used in all cell functions
Nucleoid
No envelope-chromosome, circular, double-stranded DNA
Ribosomes
-Protein synthesis
-Two subunits
-Found in all cells
-Rough ER in eukaryotic cells
Inclusions and granules
Bacterial internal structures
-Intracellular storage bodies
-Cell can use them when environmental sources are depleted
Endospores
Inert, resting cells produce by some G+ genera
Life cycle of endospores
Vegetative cell- metabolically active and growing
Endospore- adverse environment conditions; capable of high resistance and very long-term survival
Sporulation
Formation of endospores
Germination
Return to vegetative growth
Coccus
spherical shaped
Bacillus
Rod shaped
Coccobacillus
Very short and plump shape (football)
Vibrio
Gently curved shape
Spirillum
Helical, comma, twisted rod shape
Spirochete
Spring-like shape
Pleomorphism
variation in cell shape and size within a single species
Bacterial arrangements
arrangements of cells is dependent on pattern of division
Cocci arrangements
-Singles
-Diplococci- in pairs
-Tetrads- groups of four
-Irregular clusters
-Chains- strep
-Cubical packets (sarcina)
Bacilli arrangements
-Diplobacilli
-Chains
-Palisades
How do prokaryotes provide for eukaryotes?
-Recycling carbon and nitrogen
-C fixation
-N fixation
Carbon fixation
converting CO2 to organic C
Nitrogen fixation
covert nitrogen to ammonia
Microbial ecology
study of symbiotic relationships
Community
Prokaryotes live in groups that interact with organisms
Symbiotic relationships
Any interaction between different species that are associated with each other within a community
Mutualism
Both populations benefit
Amensalism
Population A is harmed while population B is unaffected
Commensalism
Population A is benefitted while population B is unaffected
Neutralism
Both populations are unaffected
Parasitism
Population A is benefitted while population B is harmed
Microbiome
all the microorganisms that are associated with a certain organism or environment
Resident microbiota
microorganisms that are always present
Transient microbiota
microorganisms that are only temporarily present- often pathogenic
Classification of prokaryotes
Shapes, staining patterns, and biochemical or physiological differences- more recently added nucleotide sequences in genes
Bergey’s manual of determinative bacteriology
The main source of how to classify bacteria
Archea
-primitive, adapted to extreme habitats, and modes of nutrition (adapt to heat, salt, acid pH, pressure, and atmosphere)
-Unicellular
-More closely related to eukaryotes than bacteria
-Unique membrane lipids and cell walls
-Contain unique genetic sequences in the rRNA
Phylum proteobacteria
-Gram-negative
-Additional cell membrane
-Spirochetes, CFB
Phylum Firmicutes
-Mainly gram-positive with low G and C content
Pathogens- anthrax. tetanus, listeriosis
Phylum actinobacteria
-Gram-positive with high G and C content
Pathogens: diphtheria and tuberculosis
Phenotypic ID of prokaryotic cells
cell wall structure, shape, arrangement, and physiological traits
restricted to bacterial disease agents
Bacterial Species
collection of bacteria cells which share an overall similar pattern of traits
Bacterial strain or variety
Culture derived from a single parent that differs in structure or metabolism from other cultures of that species
Bacterial type
a subspecies that can show differences in antigenic makeup, susceptibility to bacterial viruses, and in pathogenicity
Photosynthetic bacteria
Photosynthesize
Cyanobacteria- gram-negative cell walls-have extensive thylakoids with photosynthetic chlorophyll pigments and gas inclusions
Green and purple sulfur bacteria
Gliding, fruiting bacteria
Rickettsias
-Tiny gram-negative bacteria
-Most are pathogenic
-Obligate intracellular pathogens (can’t multiply outside host cell)
-Rickettsia rickettsii
Rickettsia rickettsii
Rocky Mountain spotted fever
Chalmydias
-Tiny
-Obligate intracellular parasites
-Not transmitted by arthropods
-Chlamydia trachomatis
-Chlamydia pneumoniae
Chlamydia trachomatis
severe eye infection and one of most common STDs
Chlamydia pneumoniae
lung infections
6 I’s of Culturing microbes
-Inoculation
-Isolation
-Incubation
-Information gathering
-Inspection
-Identification
Bacterial culture Isolation
-Separating one species from another
Streak plate
Pour plate
Spread plate
Bacterial culture Inoculation
intro of sample into a container of media
Bacterial culture Incubation
putting under conditions that allow growthI
Bacterial culture Inspection
pure culture vs mixed culture
checking for contamination
Bacterial culture Identification
-Cell and colony morphology or staining characteristics
-DNA sequence
-Biochemical tests
-Immunological tests
Classification of medias
-Physical state- liquid, semisolid, solid
-Chemical composition- synthetic and complex
-Functional type
Agar
-Most common solid media
-Solid at room temp
-Provides a framework to hold moisture and nutrients
-Not digestive for most microbes
Synthetic media
contains pure organic and inorganic compounds in an exact chemical formula
Complex or nonsynthetic media
Contains at least 1 ingredient that is not chemically definable
General purpose media
grows a broad range of microbes, usually not synthetic
Enriched media
Contains complex organic substances
Selective media
contains one or more agents that inhibit growth of some microbes and encourage growth of desired microbes
Differential media
Allows growth of several types of microbes and displays visible differences among those microbes
Reducing media
contains a substance that absorbs oxygen or slows penetration of oxygen into medium; anaerobic bacteria
Carb fermentation media
contains sugar that can be fermented, converted to acids, and a pH indicator to show this reaction
Basic stain
Stain negatively charged molecules and structures- result is positive stain
Acidic stains
Stain positively charged molecules and structures- result can be negative or positive stain
Negative stains
Stains background, not specimen
Endosymbiotic theory
The theory that mitochondria and chloroplasts originated from prokaryotes
-Mereschknowski
-Wallin
Lynn Margulls
Eukaryotic flagella
-Bigger than in prokaryotes
-Only present in sperm in humans
Cilia
Motility, feeding, and filtering
-Shorter and more numerous than flagella
Eukaryotic Cell wall (membrane)
-Provides structural support and shape
-Fungi have thick layer of polysaccharide fibers compose of chitin or cellulose
Cytoplasmic (cell) membrane
-Bilayer of phospholipids
-Sterols confer stability
-Selectively permeable
Nucelus
-Compact sphere
-Nuclear envelope contains pores
-Contains chromosomes
Nucleolus
The dark area of the nucleus where rRNA synthesis and ribosome assembly occur
Phases of Mitosis
Prophase–>Metaphase–>Anaphase–Telophase–>Cytokinesis
Prophase
The first part of mitosis. Genetic material condenses
Metaphase
The second part of mitosis. Chromosomes line up in the middle
Anaphase
The third part of mitosis. Separation starts
Telophase
The final phase of mitosis. Chromosomes move to the poles and cleavage begins
Cytokinesis
Final and complete separation into two identical daughter cells
Rough endoplasmic reticulum
ribosomes; synthesize proteins; extension of nucleus
Smooth endoplasmic reticulum
No ribosomes; nutrient processing, synthesis, and storage of lipids
Golgi apparatus
Modifies, stores, and packages proteins
-Creates vesicles
Stacks of flattened sacs called cisternae
Transport processes
Nucleus–>rough er–> Golgi–> vesicles–> secretion
Lysosomes
-Vesicles containing enzymes from Golgi
-Intracellular digestion of food particles and protection against invading microbes
Vacuoles
Membrane bound sac containing particles to be digested, excreted or stored Membrane-bound
Phagosome
Vacuole merged with a lysosome
Mitochondria
-Energy production (ATP)
-Outer membrane and inner membrane with folds called cristae
-Divide independent of cell
-Contain DNA and prokaryotic ribosomes
Chloroplast
-Photosynthesis
-Thylakoids stacked into grana
-Primary producers of organic nutrients for other organisms
-Found in algae and plant cells
Eukaryotic cytoskeleton
-Flexible framework of proteins, microfilaments, and microtubules form a network throughout cytoplasm
-Movement of cytoplasm, amoeboid movement, transport, and structural support
Algae
-Eukaryotic organisms
-Usually unicellular and colonial
-Photosynthesize with chlorophyll
-Can have flagella
-Have a cell wall
-Biggest producers of oxygen
Protozoa
-Unicellular eukaryotes that lack tissues and share similarities in cell structure, nutrition, life cycle, and biochemistry
-Lack a cell wall
-Colonies rare
-Most are harmless, free-living in a moist habitat
-Heterotrophic
-Cytoplasm is divided into ectoplasm and endoplasm
-Some are animal parasites spread by an insect vector
-Diverse
-Most have locomotor structures
Microscopic vs macroscopic forms of algae
Microscopic- unicellular, colonial, and filamentous
Macroscopic- The colonies
Free living, fresh and marine water alage
Plankton
Dinoflagellates
A group of algae that can cause red tides and give off toxins that cause food poisoning with neurological symptoms
How do protozoa feed?
By engulfing other microbes and organic matter
Protozoan Trophozoite
Motile feeding stage
Protozoan cyst
Dormant resting stage when conditions are unfavorable for growth and feeding
Protozoan Reproduction
Sexually (conjugation) and asexually (mitosis or multiple fission)
Mastigophora (euglena)
*Protozoa
-Primarily flagellar motility, some flagellar and amoeboid
-Sexual reproduction
Sarcodina (Amoeba)
*Protozoa
-Primarily amoeba
-Asexual by fission
-Most free-living
Ciliphora (Paramecium)
*Protozoa
-Cilia
-Trophozoites and cysts
-Most free-living
-Harmless
Apicomplexa
*Protozoa
-Motility absent except male gametes
-Sexual and asexual reproduction
-Complex life cycle
-All parasitic
T. Brucei
African sleeping sickness
T. Cruzi
Chaga’s disease; south America
Trypanosomes-Trypanosoma
-Pathogenic flagellates
-T. Brucei and T. Cruzi
-Infect animal is bit by a bug–> bug bites human or another animal and infects them–>cycle continues
Entamoeba histolytica
-Infective amoeba
-amebic dysentery
-Worldwide
-Contracted via contaminated water
-Life cycle takes place in digestive tract
Parasitic Helminths
-Multicellular animals
-Parasitize host tissue
-Mouthparts for attachment to or digestion of host tissues
-Well-developed sex organs that produce eggs and sperm
-Fertilized eggs go through larval period in or out of host body
Flatworms
-Flat, no definite body cavity
-Have a digestive tract, blind pouch, simple excretory and nervous systems
-Includes cestodes (tapeworms)
-Includes Trematodes (flukes)
Cestodes
tapeworms
Trematodes
Flukes
Flattened, non-segmented worms with sucking mouth parts
Nematodes (Round worms)
Round, complete digestive tract, protective surface cuticle, spikes and hooks on mouth
How are parasitic helminths acquired by humans?
-Ingestion of larvae or eggs in food
-from soil or water
-carried by insect vectors
Heartworm Life Cycle
1.) Mosquitos take a blood meal and the heartworm larvae enter the bite wound
2.) Adults in the pulmonary arteries
3.) Adults produce microfilariae that are found in peripheral blood
4.) Mosquito takes a blood meal and ingests microfilaria
5.) Microfilariae migrate in mosquito
6.) Enter the first larvae stage
7.) After third larvae stage they enter the mosquitos head so they can enter a bite wound
Heterotroph
An organism that can’t produce their own food and instead takes nutrition from other organic sources; mainly plant and animal matter
Saprozoic
Feeding on dead or decaying plant and animal matter
What are the two morphologies of microscopic fungi?
Yeast and hyphae
Yeast
-Microscopic fungi
-Round ovoid shape
-Soft uniform texture and appearance
-Asexual reproduction- budding
Hyphae
-Microscopic fungi
-Long filamentous fungi or molds
Fungal Nutrition
-All are heterotrophic
The majority are harmless saprobes living off of dead plant or animal matter
-Some are parasites living on the tissues of other organisms
Mycoses
Fungal infection
Filamentous Fungi
-Mass of hyphae called mycelium
-Cotton, hairy, or velvety texture
Septate
cross walls that divide hyphae
Vegetative hyphae
digest and absorb nutrients
Reproductive hyphae
produces spores for reproduction
Phylum zygomycota
-zygospores
-Mostly sporangiospores and some conida
Phylum ascomyota
-Ascospores
-Conida
Phylum Basidiomycota
-Basidiospores
-Conida
Phylum Chytridomycota
-Flagellated spores
Fungal Asexual Reproduction
Spores formed through budding or mitosis; sporangiospores or conidia
Conidia
-Asexual fungal spores
-Produced on the side or tip of hyphae
-Single-celled and can be produced in chains or singly
-When mature they detach and are exposed to external environment
Sporangiospores
-Asexual fungal spores
-Produced inside sac-like cells called sporangia (protect them until mature)
-Spherical or cylindrical in shape
-Once sporangium matures it blackens and splits open to release the sporangiospores
Sexual Fungal Reproduction
spores formed following fusion of two different strains and formation of sexual structure
Zygospores
-Formed by Zygomycete fungi through conjugation
-Two compatible hyphae fuse to create a thick-walled resistant spore
-typically spherical in shape
Ascospores
-Produced by ascomycete fungi
-Ascospores develop inside a sac like structure called an ascus
-Very shape depending on species
Basidiospores
-Found in basidiomycete fungi
-Produced on specialized club-shaped structures called basidia
-Typically single celled and often with a smooth or ornamented surface
Chytridomycota
-Division of zoosporic organisms
-Amphibian chytrid fungus (chytridiomycosis)
Chytridomycosis
-Amphibian chytrid fungus
-An infectious fungal disease that can be fatal to amphibians and has caused extinctions
Fungal Identification
-Isolation on specific media
-Observation of: asexual spore-forming structures and spores, hyphal type, colony texture and pigmentation, physiological characteristics, genetic makeup
Adverse impacts of fungi
-Mycoses, allergies, toxin production
-Destruction of crops and food storages
Beneficial Impacts of Fungi
-decomposers of dead plants and animals
-sources of antibiotics, alcohol, organic acids, vitamins
-Used in making foods and in genetic studies
Penicillin
-An antibiotic derived from the fungi Penicillium
-Most commonly used for streptococcus pyogenes (strep throat)
Thrush
An abundance of yeast can occur as a result of taking too many antibiotics
