Module 3: Anatomy of Microorganisms Flashcards
____ refers to any cell that contains a clearly-defined nucleus and membrane-bound organelles.
Eukaryotic Cells
____ refers to any unicellular organism that does not contain a membrane bound nucleus or organelles.
Prokaryotic Cells
Eukaryotic Cells are found in ____ (4).
- animals
- plants
- fungi
- protist cells
Prokaryotic Cells are found in ___ (2).
- bacteria
- archaea
How do prokaryotic and eukaryotic cells divide?
- Eukaryotes - Mitosis
- Prokaryotes - Binary Fission
The name Domain Eukaryota or Eukarya comes from the Greek words: (2)
- eu - true
- karyon - nut or kernel
Enumerate eukaryotic cell structures. (14)
- Cell Wall & Pellicle
- Chloroplasts
- Cilia & Flagella
- Cytoplasmic Matrix
- Endoplasmic Reticulum
- Golgi Apparatus
- Lysosomes
- Microfilaments, Intermediate Filaments, & Microtubules
- Mitochondria
- Nucleolus
- Nucleus
- Plasma Membrane
- Ribosomes
- Vacuole
___ is a structure that strengthens and gives shape to the cell.
Cell Wall
___ is a structure for photosynthesis, the trapping of light energy and the formation of carbohydrates from CO2 and water.
Chloroplasts
___ is a structure for cell movement.
Cilia and Flagella
____ is the environment for other organelles; the location of many metabolic processes.
Cytoplasm or Cytoplasmic Matrix
___ is a structure for the transport of materials, proteins, and lipid synthesis.
Endoplasmic Reticulum
___ is a structure for the packaging and secretion of materials for various purposes; lysosome formation.
Golgi Apparatus
___ is a structure for intracellular digestion.
Lysosome
___ are structures for cell structure and movements and form the cytoskeleton.
Microfilaments, Intermediate Filaments, and Microtubules
___ is a structure for energy production through the use of the tricarboxylic acid cycle, electron transport, oxidative phosphorylation, and other pathways.
Mitochondria
___ is a structure for ribosomal RNA (rRNA) synthesis; ribosome construction.
Nucleolus
___ is a structure that is a repository or stores genetic information; the control center of the cell.
Nucleus
___ is a structure for mechanical cell boundary; selectively permeable barrier with transport systems; mediates cell-to-cell interactions and adhesion to surfaces; secretions.
Plasma Membrane
____ are structures for protein synthesis.
Ribosomes
___ is a structure for temporary storage and transport, digestion (food), and water balance (contractile).
Vacuole
The name Prokaryotes or Procaryotes is coined from the two Greek words: (2)
- pro - before
- karyon - nut or kernel
Enumerate prokaryotic cell structures. (11)
- Capsules and Slime Layers
- Cell Wall
- Endospore
- Fimbriae and Pili
- Flagella
- Gas Vacuole
- Inclusion Bodies
- Nucleoid
- Periplasmic Space
- Plasma Membrane
- Ribosomes
___ are structures for the resistance to phagocytosis, adherence to surfaces.
Capsules and Slime Layers
___ gives bacteria shape and protection from lysis in dilute solutions.
Cell Wall
___ is a structure for survival under harsh environmental conditions.
Endospore
___ is a structure for the attachment to surfaces, bacterial mating.
Fimbriae and Pili
___ is a structure that provides the power of motility or self-propulsion.
Flagella
___ is a structure that provides buoyancy for floating in aquatic environments.
Gas Vacuole
___ are structures for the storage of carbon, phosphate, and other substances.
Inclusion Bodies
___ is a structure for the localization of genetic material (DNA).
Nucleoid
___ is a structure that contains hydrolytic enzymes and binding proteins for nutrient processing and uptake.
Periplasmic Space
___ is a structure that is a selectively permeable barrier, mechanical boundary of cell, nutrient and waste transport, location of many metabolic processes (respiration, photosynthesis), detection of environmental cues for chemotaxis.
Plasma Membrane
___ are structures for protein synthesis.
Ribosomes
What structures do prokaryotes and eukaryotes have in common? (4)
- Flagella
- Plasma Membrane
- Cytoplasm
- Ribosomes
___ refers to unicellular organisms without a nucleus . They lack organelles and peptidoglycan but have cell walls.
Archaebacteria
Archaebacteria live in EXTREME environments: (2)
- hot springs, deep ocean
- where there is no oxygen
How do archaebacteria get energy?
Chemosynthesis
What are some of the biological functions of the cell wall? (4)
- protects the cell against ion and pH fluctuations, osmotic stress, degrading enzymes, or predacious bacteria.
- helps in maintaining the shape and envelope rigidity of the cell.
- promotes cell adhesion to surfaces.
- studies with nanotechnology due to their ability to self-assemble protein units w/o the aid of enzymes.
What are some of the biological functions of the cell wall? (4)
- protects the cell against ion and pH fluctuations, osmotic stress, degrading enzymes, or predacious bacteria.
- helps in maintaining the shape and envelope rigidity of the cell.
- promotes cell adhesion to surfaces.
- studies with nanotechnology due to their ability to self-assemble protein units w/o the aid of enzymes.
What is the future prospect of the cell wall?
The S-layer could be used for technology such as in drug delivery systems and novel detection systems for toxic chemicals.
What are the major types of Archaebacteria cell wall? (5)
- Type 1
- Type 2
- Type 3
- Type 4
- Type 5
Type 1 of Archaebacteria Cell Wall: The most common type of archaeal cell wall is an S-layer composed of either ____ or ____.
Protein; Glycoprotein
How thick is the Type 1 Archaebacteria Cell Wall?
20-40nm
Type 2 of Archaebacteria Cell Wall: Additional layers of material are present outside the S-layer. In Methanosprillum, there is a ____ external to the S-layer.
protein sheath
Type 3 Archaebacteria Cell Wall: In Methanosarcina, S-layer is covered by a chondroitin-like material called ____.
Methanochondroitin
Type 4 Archaebacteria Cell Wall: In some Archae like Methanothermus and Methanopyrus, S-layer is the outermost layer and is separated from the plasma membrane by a peptidoglycan-like molecule called ____.
Psuedomurein
How does Pseudomurein differ from Peptidoglycan? (3)
Pseudomurein has:
1. N-acetyltalosaminuronic acid instead of N-acetyl muramic acid
2. L-amino acids instead of D-amino acids that cross-links
3. Beta (1->3) glycosidic linkage instead of Beta (1->4) glycosidic linkage
Type 4 Archaebacteria Cell Wall: In this type, the S layer is ____. Instead, the archeal cell wall is a ____ resembling ____ bacteria.
absent;
single, thick, homogenous layer;
Gram-positive
___ is a thin layer lining the inner surface of the cell wall. It is a semipermeable membrane controlling the flow of metabolites. Chemically, it consists of lipoproteins and carbohydrates. Here, sterols are absent.
Cell Membrane
The cell membrane is best described using the ___ model.
Fluid Mosaic
The cell membrane is composed of ___% phospholipid and ___% protein.
40%; 60%
Members of Bacteria and Archaea have the same general structure of their cytoplasmic membranes, but the ____ are distinctly different.
Lipid Compositions
What are the differences between bacterial and archaeal phospholipids? (2)
- Chirality of Glycerol - the glycerol used to make archaeal phospholipids is a STEREOISOMER of the glycerol used to build bacterial and eukaryotic membranes.
- Linkage (Ester vs. Ether)
- Side Chains (Fatty Acids vs. Isoprenoids)
- Branching of Side Chains - different physical structures; can form carbon rings.
____ is a structure of a prokaryote that is a permeability barrier; regulates movement of materials into and out of the cell; contains proteins that transport nutrients into the cells and eliminates waste materials; and synthesizes cell wall components.
Cell Membrane
Fill in the blanks:
Prokaryotic Cell Membrane Functions
1. It assists with _____
2. It secretes _____
3. It carries on _____
4. It contains bases of _____
- DNA Replication (anchors DNA)
- Proteins
- Cell Respiration (ATP Synthesis)
- Flagella
The cell membrane being _____ allows small molecules like water, oxygen, carbon dioxide, and hydrophobic molecules to move freely (simple diffusion). However, large or charged molecules like proteins, sugars, and ions cannot.
Selectively Permeable
____ is a semifluid substance inside the cell membrane. It is 4/5 water and 1/5 dissolved substances (enzymes, proteins, carbohydrates, lipids, salts, vitamins, and various inorganic ions). It is where chemical reactions take place.
Cytoplasm
____ are vesicular, convoluted invaginations of the plasma membrane. It is prominent in GM+ bacteria. They are the principal sites of respiratory enzymes. They are also analogous to mitochondria in Eukaryotes.
Mesosomes
____ help to increase the surface area of the cell membrane, increasing the enzymatic content of the cell.
Mesosomes
____ is the chromosome region. It is a gel-like region containing the chromosomes and plasmids.
Nucleoid
____ are single, circular, double-stranded DNA molecules that contain all genetic information required by a cell. They are 1mm long and 10% of a cell’s total volume.
Chromosomes
____ are referred to as accessory genetic information. They are circular, supercoiled, double-stranded DNA molecules. They are 0.1-10% of the size of a chromosome and contains hundreds of genes (5-100).
Plasmids
T or F
Plasmids may contain genes for antibiotic resistance and/or disease production. They can also be transferred and spread to other bacterial cells.
T
___ consist of ribonucleic acids (rRNA) and proteins (ribosomal protein). They are < 20,000. They are nearly spherical, stain densely, and contain large and small subunits.
Ribosomes
____ are the sites for protein synthesis and for antibiotic action.
Ribosomes
T or F
The faster the cell is growing, the faster proteins are produced, the greater the number of ribosomes.
T
____ of cell energy is for protein synthesis.
90%
What are the subunits of PROKARYOTIC ribosomes? (2)
- 50s - 5s RNA & 23s RNA
- 30s - 16s RNA
= 70s
What are the subunits of EUKARYOTIC ribosomes (2)
- 60s - 5s RNA, 5.8s RNA, 28s RNA
- 40s - 18s RNA
= 80s
What are the internal membrane systems? (2)
- Photosynthetic Bacteria and Cyanobacteria
- Nitrifying Bacteria
___ contain the pigments used to capture light energy for synthesis of sugars.
Chromatophores/Chlorosomes
____ convert nitrogen compounds into plant-useable form. They house the enzymes used in deriving energy from oxidation of nitrogen compounds.
Nitrifying Bacteria
___ are a variety of small bodies within the cytoplasm. They store materials that are later used as sources of nutrients. They are a reservoir of structural building blocks. They can be categorized into GRANULES and VESICLES.
Inclusion Bodies
____ are intracellular small storage bodies. They vary in size, number, and content. Bacterial cells can use them when environmental sources deplete.
Granules and Vesicles
____ are accumulations of high molecular weight polymers synthesized from a nutrient in excess. They contain specific substances densely compacted that do not dissolve in the cytoplasm.
Storage Granules
____ is stored glucose polymer used as a carbon and energy source.
Glycogen
____ are stored phosphates.
Volutin Granules or Polyphosphate Granules
____ are small, rigid, protein-bound compartments that provide buoyancy to the cell.
Gas Vesicles (Vacuoles)
The cell wall has the ability to counter the effects of ____.
Osmotic Pressure
The cell wall provides ___ for bacteriophages (type of virus that infects bacteria; bacteria eater, they destroy host cells).
Attachment Sites
The cell wall provides a rigid platform for surface appendages and these are: ___, ____, and ____. All emanate from the cell wall and extend beyond it.
- Flagella
- Fimbriae
- Pili
The cell wall is considered to be the sites of major ____ of the cell surface.
Antigenic Determinants
What are the shapes and arrangements of bacteria? (3)
- Cocci - sphere, 1μm
- Bacilli - rods, 0.5-1 μm in width -3μm in length
- Spiral - 1~3 μm in length and 0.3-0.6μm in width
The shape and arrangement of bacteria are essential for their viability: (2)
- They protect the cell from mechanical damage (rigidity).
- They help the cell withstand pressure and prevent it from osmotic rupture or lysis.
In a ____ solution, no net movement of water occurs.
Isotonic
In a ____ solution, water moves into the cell and may cause the cell to burst if the wall is weak or damaged (osmotic lysis).
Hypotonic
In a ____ solution, water moves out of the cell, causing its cytoplasm to shrink (plasmolysis).
Hypertonic
The bacterial cell wall differs from that of all the other organisms by the presence of _____.
Peptidoglycan
The peptidoglycan (mucopeptide) is composed of alternating chains of ____ and ____, cross-linked by peptide chains.
- N-Acetyl Glucosamine (NAG)
- N-Acetyl Muramic Acid (NAM)
The ____ is responsible for the rigidity of the bacterial cell wall and for the determination of cell shape.
Peptidoglycan
Based on the composition of the cell wall and staining, bacteria are classified into ___ and ____.
Gram Positive & Gram Negative
NAG and NAM subunits are covalently joined to one another to form a _____.
Glycan Chain
____ serve as the backbone of the peptidoglycan molecule.
NAG (N-acetyl glucosamine)
NAM (N-acetyl muramic acid)
____ are different bacterial species with different amino acid composition.
Tetrapeptides
The _____ cell wall is characterized by the presence of a very thick peptidoglycan layer (≈30 layers).
It is 20-80 nm thick.
It contains 90% Peptidoglycan and 10% Teichoic Acid.
It is fully permeable to many substances (sugars, amino acids, ions.
Gram Positive
What are interwoven in the cell wall of Gram-positive bacteria? (2)
- Teichoic Acids
- Lipoteichoic Acids
- covalently bonded to NAM (N-acetyl muramic acid)
Teichoic acids are composed of polymers of: (3)
- Glycerol
- Phosphates
- Sugar Alcohol-Ribitol
The ____ cell wall contains a thin peptidoglycan layer adjacent to the cytoplasmic membrane. It also contains an additional outer membrane composed of phospholipids and lipopolysaccharide (LPS) which face into the external environment and periplasmic space.
Gram-Negative
___ is a bilayer membrane and is composed of phospholipids, polysaccharides, and proteins. It also contains lipopolysaccharide (LPS). It is attached to the peptidoglycan by almost a continuous layer of lipoproteins.
Outer Membrane
The outer membrane also acts as a ____.
Coarse Sieve
The outer membrane has ____, specialized channel-forming proteins, channels for low molecular weight substances.
Porins
____ are systems that translocate proteins produced to the outside of the outer membrane.
Secretion Systems
The LPS (in the outer membrane) present on the GM- cell wall consists of 3 regions, these are: (3)
- polysaccharide determining O antigen
- core polysaccharide
- glycolipid portion/Lipid A
The ____ or ___ causes a form of septic shock for which there is no direct treatment.
LPS (lipopolysaccharide); endotoxin
The ____ cause symptoms of disease in animals. They provide for immunological distinction and immunological variation among strains of bacteria.
Endotoxin
____ is one of the parts of LPS that is responsible for the toxic properties of GM- bacteria (endotoxin). It anchors the LPS in the bilayer.
Lipid A
____ is one of the parts of LPS that is a side chain portion of LPS directed away from the membrane. They are chains of sugar molecules with varying compositions and lengths. It is used to identify certain species and strains.
O-specific polysaccharide (O-antigen)
____ is a gel-like fluid (periplasm) and protein-filled (secreted proteins). It is a very active area of cell metabolism. It contains digestive enzymes, transport proteins.
Periplasmic Space
The periplasmic space is most observed in __ bacteria.
GM-
In Streptococcus pneumoniae (Gram-positive), Teichoic acid bears the antigenic determinants called the ____.
Forssman Antigen
____ interferes with peptidoglycan synthesis; binds to proteins involved in cell wall synthesis; prevents cross-linking of glycan chains; more effective against G+ bacteria; and is modified to create derivatives that can pass through porin channels.
Penicillin
___ is found in many body fluids. It breaks the bond between the NAM (N-acetyl muramic acid) and NAG (N-acetyl glucosamine) molecules.
Lysozyme
What are the differences between the GM+ and GM- cell walls? (Mnemonic)
GM+
LONG (Lipopolysaccharide, Outer Membrane, Negative, Gram)
GM-
PPT (Positive, Peptidoglycan, Teichoic Acid)
The Gram Staining Method was devised by ____ in ____.
Hans Christian Gram, 1884
What solutions are needed in the Gram Staining Method? (4)
- Crystal Violet - primary stain
- Iodine - mordant
- 95% Ethanol - decolorizer
- Safranin - counterstain
Give one example of a GM+ and GM- bacteria.
GM+ - Staphylococcus aureus
GM- - Escherichia coli
What species have no cell wall yet have sterols in their cell membranes for stability?
Mycoplasma species
What are the cell wall appendages? (5)
- Glycocalys (Capsule & Slime Layer)
- S-Layer (Surface Proteins)
- Flagella
- Fimbria
- Pili
___ is a general term for any network of polysaccharide (small proteins) lying outside the cell.
Glycocalyx
____ is a less discrete structure or matrix which embeds the cell; diffuse and irregular,
Slime Layer
____ is a discrete detectable layer of polysaccharides deposited outside the cell wall; distinct and gelatinous (thicker and more rigid).
Capsule (True Capsule)
In most species, the solid material in capsules and slime layers is called a ____, though in some species, it is a polypeptide or protein.
Complex Polysaccharide
When glycocalyx is tightly bound to the cell wall of bacteria, it is referred to as a ____. It is gelatinous in nature and cannot be easily stained and removed from the bacterial cell wall.
Capsule
The glycocalyx is called ___ if it is loosely bound
to the cell wall of bacteria. It is irregular and can easily be removed from the bacterial cell wall.
Slime Layer
Since capsules are antiphagocytic, they contribute ____.
Virulence
Capsules mediate ____ of cells to surfaces.
They protect bacterial cells from _____.
Capsules protect soil bacteria from ____.
When overproduced, capsules may become ____ of carbohydrates.
Adherence
Engulfment
Dessication
Reserves
The function of glycocalyx in terms of disease:
It is a virulence factor in most bacteria, and it contributes to their ability to cause diseases in their host.
The function of the glycocalyx in terms of protection:
Glycocalyx protects bacteria from antibiotics, and chemicals and against the lytic and phagocytic activities of the host’s white blood cells.
The function of the glycocalyx in terms of adherence to surfaces:
The sticky nature of the glycocalyx enables bacteria to attach themselves firmly to the surface of their host.
The function of the glycocalyx in terms of avoidance of desiccation:
Glycocalyx (especially capsule) contains water as its constituent. This help to prevent dryness of the bacterial cell.
The function of the glycocalyx in terms of cell-cell recognition:
The glycocalyx carries receptors on their surface that allow them to bind to other cells of close species.
The ____ of GM+ Streptococcus mutans allows it to accumulate on tooth enamel and one of the causes of cavities.
Slime Layer
Other bacteria in the mouth become trapped in the slime layer and form a ____ & eventually a buildup of ____.
Biofilm; Plaque
____ is a polysaccharide-encased mass of bacteria coating a surface (e.g Streptococcus mutans and dental plaque).
Biofilm
___ is a long protein structure. It is helical, corkscrew-shaped. It may regenerate when cut off. It is also responsible for bacterial motility/locomotion, pushing a bacterium through a liquid. It spins like a propeller (rotates clockwise and counterclockwise).
Flagella
The flagella is found in all motile bacteria except in ____.
Spirochetes
Flagella is also termed as the ____ antigen.
H
Flagella has three basic parts: (3)
- Filament (Flagellin) - twisted but w/ a hollow core.
- Basal Body (Motor) - anchored in the cell membrane and cell wall; has rings and a rod.
- Hook - a wide region at the base of the flagella; connects the two parts (basal body and filament).
Types of Flagellar Arrangements: (5)
- Polar/Monotrichous - single flagellum at one pole (e.g Vibrio cholerae)
- Lophotrichous - tuft of flagella at one pole (e.g Spirillum)
- Amphitrichous - flagella at both poles (Alkaligenes faecalis)
- Peritrichous - flagella all over (e.g E. coli, Salmonella, and Bacillus spp.)
- Amphilophotrichous - tuft of flagella at both ends
Kinds of Motility: (5)
- Swimming
- Swarming
- Twitching
- Gliding
- Sliding
___ refers to the bacterial behavior in seeking out favorable environments and avoiding harmful ones.
Taxis
- Chemotaxis
- Aerotaxis
- Phototaxis
- Magnetotaxis
____ sense chemicals and move toward regions that contain more nutrients (attractant) and away from regions with toxic materials (repellant).
Chemotaxis
____ swim to regions that contain favorable concentrations of dissolved oxygen.
Aerotaxis
____ refers to the movement to regions of optimal light intensity and quality.
Phototaxis
____ response to Earth’s magnetic field.
Magnetotaxis
Flagella are ____, and bundle and rotate together only when rotating _____.
left-handed helices; counterclockwise
When some of the rotors reverse direction, the flagella unwind and the cell starts ____.
tumbling
____ may happen occasionally, leading to the cell seemingly THRASHING about in place, resulting in the reorientation of the cell.
Tumbling
If in counterclockwise, the flagellum ___.
swims/runs - forward movement
If in clockwise, the flagellum _____.
tumbles - stops and rolls
The clockwise rotation of a flagellum is suppressed by ____, but the motor is highly adaptive to this.
chemical compounds favorable to the cell (e.g food)
What happens when a flagellum is moving in a favorable direction?
The concentration of the chemical attractant increases and TUMBLES are continually suppressed.
What happens when a flagellum is moving in an unfavorable direction (e.g away from a chemical attractant)?
Tumbles are no longer suppressed and occur much more often, with the chance that the cell will be thus reoriented in the correct direction.
The detection of motility and presence of flagella can be tested by: (6)
- direct observation by hanging drop method
- dark field microscopy
- motility media (Sulfide Indole Motility (SIM) Media)
- flagellar staining
- electron microscopy
- immunological detection of H antigen
____ are tiny, hollow projections not involved in the movement of the cell. They are shorter, thinner, and straighter than flagella. They are made up of PILIN proteins, helical structures around a central hollow core.
Pili
What are the types of pili? (2)
- Attachment Pili (Fimbriae) - with adhesins
- Conjugated/Sex/F Pili - longer than attachment pili; DNA transfers from one cell to another.
____ are short protein appendages, shorter than flagella. They help the bacterial cell adhere to surfaces.
Pili
Adherence of pili can be blocked by ____.
Antibodies
___ are hair-like surface appendages; shorter and thinner than the flagella; formed by protein subunits - pilin.
Fimbriae
The fimbriae can form ____.
Pellicles
____ refers to the clumping of RBCs.
Hemagglutination
____ are similar in structure to fimbriae but are generally longer. They function in gene transfer and may serve as specific receptors for certain types of virus particles.
Conjugation Pilus
____ are the resting (dormant) stages of vegetative cells of some bacterial species. They are very resistant to heat and harmful genes. They are produced by SPORULATION. They may be dormant for 100 years.
Endospores/Sporess
____ are the resting (dormant) stages of vegetative cells of some bacterial species. They are very resistant to heat and harmful genes. They are produced by SPORULATION. They may be dormant for 100 years.
Endospores/Sporess
Endospores are ultimate protection for the ____.
Spores form within the cell and contain a ____ of the bacterial genome.
Endospores are not a form of reproduction, because only ____ germinate from each spore.
They can be found ____ (2).
bacterial genome
full copy
new cells
Bacillus, Clostridium
An endospore consists of the ff: (4)
- Core
- Cortex
- Spore Coat
- Exosporium
___ is a thin, delicate covering made of protein in an endospore.
Exosporium
___ is composed of spore-specific proteins; sieve; excludes substances such as lysozyme.
Spore Coat
_____ is a loosely cross-linked peptidoglycan. It maintains the core in a dehydrated state. It protects the endospore from effects of heat.
Cortex
____ has small, acid-soluble proteins that bind DNA. It contains the core wall, cell membrane, cytoplasm, nucleoid, etc. It is rich in DIPICOLINIC ACID and CALCIUM IONS; partially dehydrated (10-30% water). It also contains core-specific proteins).
Core (Spore Protoplast)
The cortex, which may occupy as much as half the spore volume rests _____.
It is made up of ____ that is less cross-linked than in vegetative cells.
The spore cell wall is inside the cortex and surrounds the protoplast or spore core.
It has normal cell structures but is _____.
beneath the spore coat
peptidoglycan
metabolically inactive
The location of endospores can be classified as: (3)
- Central
- Subterminal
- Terminal
____ is a complex, yet highly ordered sequence of changes that initiate when cells are grown in low amounts of carbon or nitrogen. This goes on around 8 hours.
Sporulation
____ is triggered by brief exposure to heat or certain chemicals.
Germination
____ is a differential staining technique that is used to distinguish between the vegetative cells and the endospores.
Endospore Stain/Endospore Staining Method
The endospore stain (Wirtz-Conklin) was designed by _____ and ____ during the 1930s.
Alice B. Schaeffer
MacDonald Fulton
The cytoplasm can be divided into two parts: (2)
- Ectoplasm - thin, clear, gel-like outer layer that acts as a membrane.
- Endoplasm - more watery grainy mass containing structures called organelles.
In the endoplasm: (2)
- food synthesis occurs.
- food stores in the form of glycogen or protein called chromatoidal bodies.
In the ectoplasm;
- envelopes the cell,
- fxns as the locomotor apparatus for the procurement & ingestion of food,
- in respiration, discharge of metabolic wastes & protection of the org.
Locomotory organelles arising from the ectoplasm may vary from: (3)
- Cilia – in Ciliates; numerous short threads are distributed over the surface of the body.
- Pseudopodia – false feet; in Amoebae (crawling movement).
- Flagella - in flagellates, hair-like projections.
____ are microorganisms that absorb liquid nutrients from the medium or ingest bacteria & cells at any site of the body surface.
Protozoans
Other protozoans have a specialized cell mouth called _____ usu; located in anterior end of the body.
Cytostome
Ciliates have in addition a cell ____ at the posterior end of the body & through which particulate food wastes are discharged.
anus/cytopyge
The typical life stages of protozoans: (2)
- Cyst - non-motile; infective stage; highly resistant
- Trophozoite - vegetative or feeding forms
____ is a more or less central body in the vesicular nucleus of certain protozoa (e.g trypanosomes, parasitic amebae), w/ the chromatin.
Endosome/Karyosome
____ move with the help of the Flagella. Their movement is whip-like (e.g Trypnosoma & Leishmenia - blood pathogen, Giardia - intestinal parasite, Trichomonas - reproductive tract pathogen).
Flagellates
What are some of the characteristic features of the stained trophozoite? (3)
- two nuclei (Nu) w/ central karyosomes (k)
- fibrils running the length of the parasite - axonemes (Ax)
- Median Bodies (MB) or Parabasal Bodies
Median Bodies are most believed to be involved with the _____ and _____.
adhesive disk; its formation
The ____ plays a role in the attachment of the trophozoite to the intestinal epithelium.
adhesive disk
T or F
Fungi can be single-celled or very complex multicellular organisms.
T
The three major groups of fungi: (3)
- multicellular filamentous molds
- macroscopic filamentous fungi that form large fruiting bodies (mushrooms)
- single-celled microscopic yeasts
The structures that help fungi absorb and digest food: (2)
- Hyphae - the body of a typical fungus; consists of many tiny tubes
- Mycelium - hyphae tangled into a thick mass
Fungi also has an aerial hyphae called ____ which branch to form ____.
condiophores; sterigma
____ is the first Penicillium fungi used for the isolation of penicillin antibiotics, which are used for the treatment of GM+ bacteria. It is also used in the production of other β-lactam antibiotics.
Penicillium chrysogenum (Penicillium notatum)
The hyphae of fungi may or may not be divided into separate cells by the ____.
septa
___ is a unicellular fungus; eukaryotic; facultative anaerobic; capable of forming colonies on culture media; occurs worldwide; and is over 1,500 species.
Yeast
___ are small, lemon-shaped single cells that are about the same size as RBCs. They multiply by building a daughter cell off from the original parent cell.
Yeasts
The protective shell that surrounds a virus is called a ____. It is made up of many identical protein subunits. It protects the genetic material of a virus. It is 50% of a virus’ weight. It may or may not be enveloped.
Capsid
____ is a lipid-containing membrane that surrounds some virus particles. It is located outside the capsid and is acquired during viral maturation.
Envelope
What are the different shapes of a virus? (4)
- Helical (tobacco mosaic virus)
- Polyhedral (adenovirus)
- Spherical (influenza virus)
- Complex (bacteriophage)
Structures in relation to function of a virus’ envelope: (3)
- protects the virus from drying (enhances transmissions)
- makes virus more SUSCEPTIBLE to chemical agents that dissolve lipids
- promotes attachment to the host cell membrane (by spike)
