| Question | Answer |
|---|---|
| 3 Domains/classifications | 1. Prokaryo 2. Archaea – strong type 3. Eukaryo |
| Structure of a Prokaryotic Cell | 1. Small cells 2. No nuclear membrane – free floating DNA 3. Structures: appendages, cell envelope, cytoplasm |
| Structures of a Bacterial Cell | 1. Prokaryotic organisms 2. Unicellular 3. Reproduces through binary fission |
| What is Binary Fission? | Reproduction that ends up with 2 identical daughter cells |
| What does Binary Fission need in order to occur? | – Sufficient amount of nutrients and a good environment (stops when no more nutrients) |
| How are bacteria cells classified? (2 things) | 1. Shape 2. Arrangement |
| What shape is the Vibrios? | Comma shaped rods |
| 4 important cellular structures | 1. Cell envelope (glycocalyx, cel wall, cel membrane) 2. Nuclear Body – genetic info 3. Endospores – how they evade antibiotics 4. Flagella/pilli – communication, mobility) |
| What are the 3 layers of a Cell Envelope | 1. Glycocalyx 2. Cell Wall 3. Cell Membrane |
| Structures of the Glycocalyx (cell envelope) (2) – Pro | 1. Polysaccharides – sticky sugar; help with attachment, communication, getting things from outside to in 2. Either Slime or Capsule layer |
| Functions of the Glycocalyx (cell envelope – outer) (5) – Pro | 1. Communication between cells 2. Anchoring of cells 3. Formation of biofilms 4. Protection from pathogens 5. Involved in the immune system |
| Capsule | – Thick, definite shape – Contributes to cell virulence (what allows a cell to cause a disease) – Protection from phagocytosis and drying – Immunogenic – can mount an immune response – Some vaccines directed at capsule |
| Slime layer | – Thinner, less uniform – Protects agaisnt drying – Promotes adherence (cell-to-cell;surface) – e.g. oral bacteria and teeth |
| Cell Wall (2nd Layer of Cell Envelope) | – Provides strength agaisnt osmotic pressure – Composed of peptidoglycan (PG) – determines Gram Stain |
| 4 Steps of the Gram Stain | 1. Apply crystal violet (purple dye) 2. Apply iodine to lock colour in 3. Alcohol wash 4. Apply safranin (red dye) |
| Structures of Gram Positive (6) | 1. Peptidoglycan (PG) – 80-90% 2. Polysaccharides (sticky sugars) 3. Thick PG layer 4. No outer membrane 5. Narrow periplasmic space 6. More permeable to molecule |
| Structures of Gram Negative (7) | 1. Lipopolysaccharide (LPS) 2. PG – 10-50% 3. Porin protein in wall 4. Thinner PG layer 5. Outer membrane 6. Extensive periplasmic space 7. Less permeable to molecules |
| Is LPS an Endotoxin? | – Yes; an endotoxin is a toxin internal to bacterial cell, helps cause infection in host cell & more resistant |
| Cell Membrane (3rd layer of Cell Envelope) – made of? | 1. Phospholipids – bilayer, heads pointing out (likes water) 2. Proteins 3. Glycolipids 4. Hopanoids – like cholesterol in humans |
| Functions of the Cell Membrane (4) | 1. Structual support 2. Metabolic functions 3. Regulates transports 4. Role in immune response |
| Cytoplasm | – Site of biochemical and synthetic activities (reactions occur, requires water) – 70-80% water – Solvent for cell nutrients – Contains cellular structures such as the nucleoid (single chromosom) and ribosoms |
| Nuclear Body | – Single chromosome strand = nuceloid – No nuclear membrane – Free floating DNA |
| Plasmids | – Extra chromosomal genetic info – Either free floating or in chromosome – Can be duplicated and passed onto offspring – Offers protective traits to bacteria |
| Ribosomes | – Protein synthesis – Made of RNA and protein – Throughout cytoplasm and on cell membranes – Usually in chains (polysomes) |
| Endospores | – Thick walled and resistance; purpose of survival |
| What are the 2 stages of endospores? | 1. Vegetative Cell 2. Endospore |
| Vegetative Cells | When environmental conditions are still good, putting energy into feeding and storing nutrients – When environmental conditions worsten = starts sporulation |
| 5 Steps of Sporulation | 1. Vegetative cell threatened 2. DNA copied & put towards end of cell (septation) 3. Sporangium engulfs forespore 4. Protective layer forms around 5. Sporangium deteriorates and releases spore |
| Germination = What is needed to reactivate the vegetative cell (4) | 1. Nutrients 2. H2O and a germinating agent 3. Digestive enzymes; exposes core to H2O 4. Spore rehydrates and releases vegetative cell |
| Appendages | – Allow for movement |
| Flagella – appendage | – Whip like motion (like helicopter) – Composed of protein flagellin |
| 3 Parts of a Flagella | 1. Filament – end of whip; long and thin 2. Hook – at the end of flagellum, anchored to basal body 3. Basal Body – rod with 1+ pairs of disk |
| Arrangement of Flagella (4) | 1. Monotrichous – single flagellum at one end 2. Lophotrichous – multiple flagellum from one end 3. Amphitrichous – both ends 4. Pertichous – all over surface |
| Periplasmic Flagella | – Internal flagella; on spirochetes – 2 long coiled threads, inbetween cell wall and membrane – Twisting motion (like itsy bitsy spider) |
| Pili – appendage | – Like bristle hair (like cilia) – Composed of protein pillin – Has point of attachments (to eachother or surfaces) |
| Sex pili | – Allows transfer of genetic info between organisms (through asexual process) |
| Bacterial Growth Requirements (3) | 1. Nurtients 2. Atmospheric 3. Temperature |
| Heterotrophs – Nutritional Requirement of Bacterial Growth | – Uses carbon from ORGANIC COMPOUNDS 1. Photoheterotrophs – gets energy from sunlight 2. Chemoheterotrophs – gets energy & carbon from organic compounds |
| Autotrophs – Nutritional Requirement of Bacterial Growth | – Uses carbon from atmospheric carbon dioxide 1. Photoautotrophs – gets energy from sunlight 2. Chemoautotrophs – gets energy from carbon compounds |
| What are the 6 Atmospheric requirements (for bacteria) | 1. Obligate Aerobes 2. Obligate Anaerobes 3. Facultative Anaerobes 4. Aerotolerant Anaerobes 5. Microaerophiles 6. Capnophiles |
| Obligate Aerobes – atm requirements (for bacteria growth) | – Grow only in the presence of oxygen – Aerobic cellular respiration |
| Obligate Anaerobes – atm requirements (for bacteria growth) | – Doesn't rely on oxygen |
| Facultative Anaerobes – atm requirements (for bacteria growth) | – Grows with or without oxygen – w/ oxygen = aerobic respiration – w/out oxygen = fermentation |
| Aerotolerant Anaerobes – atm requirements (for bacteria growth) | – Can grow in the presence of oxygen, but cannot use it – Through fermentation |
| Microaerophiles – atm requirements (for bacteria growth) | – Requires low concentration of oxygen (can't live in normal air) |
| Capnophiles – atm requirements (for bacteria growth) | – Requires more carbon dioxide than in regular air – More acidic environment |
| What are the 4 Temperature Requirements (for bacteria growth) | 1. Mesophiles 2. Thermophiles 3. Psychrophiles 4. Psychrotrophs |
| Mesophiles – temp requirement (for bacteria growth) | – Moderate temp; 25 – 40 degrees celsius |
| Thermophiles – temp requirement (for bacteria growth) | – Hotter temp; 45+ |
| Psychrophiles – temp requirement (for bacteria growth) | – Colder temp; 0 or lower |
| Psychrotophs – temp requirement (for bacteria growth) | – Grows slowly at 0, but optimal growth at 25-30 – Food spoilage |
| Generation time – bacteria growth | – Length of time required for binary fission to take place |
| 4 Phases of Bacteria Growth | 1. Lag Phase 2. Log/Exponential growth phase 3. Stationary Phase 4. Death Phase |
| Lag Phase | – 1st phase; not a lot pf growth (before) |
| Log/Exponential growth phase | – 2nd phase – rapid replication, ends due to lack of nutrients |
| Stationary Phase | – 3rd phase – # of new organisms = #of dying organisms |
| Death Phase | – 4th phase – bacteria lose ability to reproduce (even with good environment) |
| 3 examples of Unusual Prokaryotes | 1. Chlamydia 2. Rickettsiae 3. Mycoplasmas |
| Chlamydia | – Gram-negative – Rod or coccus shaped; coccobacillus (kind of both) – Must have intracellular parasites (live inside host cell) – Cannot synthesize own ATP |
| What are the 2 'bodies' of the Chlamydia replication cycle | 1. Elementary bodies (infectious form) 2. Reticulate bodies (growth form) |
| Replication Cycle (steps) of Chlamydia (6) | 1. EB attaches to host cell 2. Host cell ingests EB, housing in an inclusion (sac) 3. EB reorganizes to form a reticulate body (RB) 4. RB divides, producing multiple RBs 5. Rbs convert back to EB 6. Eb released from host cell through lysis (bursting) |
| Rickettsiae | – Small rods or coccobacilli – Contains RNA & DNA – Slime layer interferes with gram stain |
| Obligate Intracellular Parasite | – Needs host cell |
| How do Ricketsiae reproduce? | – Binary Fission – Transmitted by arthropod vectors (adding another organism to help them live) |
| Mycoplasmas | – More in hospitals – Both DNA & RNA – No cell wall (pleomorphic) – Falculative Anaerobes (w/ or w/out oxygen) – Acid fast stain (since no cell wall) |
| Acid Fast Stain | – Used for when no Cell Wall – Has ++mycolic acid (instead of PG) – Use red dye to stain (carbol fuchsin) – Acid-alcohol locks in colour (because of cell membrane lipids) – Other organisms colour blue/green |
| Archaea – Other Prokaryotes | – More closely to Eukarya than Bacteria – Unique genetic sequences in rRNA – Can survive harsh conditions (adapts to heat, salt, acid pH, changes in pressure and atmosphere) – Hyperthermophiles (hot areas) – Methane produces-sulfur reducers |
| What are the 3 types of Eukaryote Cells? | 1. Protists (protozoa) – Single-celled organisms lacking complex organization 2. Fungi (myceteae) – single or multi cellular; yeasts and mold 3. Plant and Animal |
| Eukaryotic Structures (9) | 1. Glycolcalyx 2. Cell Membrane 3. Nucleus 4. Mitochondria 5. ER 6. Golgi 7. Vacuoles 8. Cytoskeleton 9. With or without Cell Wall |
| Locomotor Appendages | – Only on some – External – Covered by extension of cell membrane – 9 pairs + 2 microtubular arrangment – Linked together by protein arms (pairs of circles on outside pic) |
| How do Flagellar locomotion move? | 1. Whipping back and fourth 2. Twirling 3. Lashing out |
| Cilia – Function | 1. Motility 2. Feeding 3. Filtering – in rows over surface; sway – help move things back and forth |
| Glycocalyx – Euk | – Outermost (comes in contact with extracellular environment) – Network of polysaccharides fibres – Slime layer OR capsule |
| Glycocalyx – Functions (Euk) (3) | 1. Protection to cell 2. Allows adherence/attachment to diff surfaces 3. Receive signals |
| Cell Wall (Euk) | – Fungi & Algae – Provides structure and shape – Composed of Chitin (polysaccharide), glycoprotein, mixed glycans (molecules that can adhere to other molecules) |
| Cell Membrane (Euk) | – Bilayer of phospolipids & sterole (heads out – H2O loving) – 2 proteins – 1. Peripheral 2. Integral – Provides stability to cells lacking a cell wall – Selectively permeable |
| Nucleus | – Actually in eukaryotic cells (not in prokaryo) – rRNA synthesis – Surrounded by double membrane = nuclear envelope – Membrane contains pores which allows certain molecules to pas through |
| Chromatin | – Dark granules (chromosomes) seen throughout the nucleus – In nucleus |
| Haploid | – Single & unpaired nucleus |
| Diploid | – Chromosome that are matched or paired |
| Mitosis – 5 stages | 1. Prophase 2. Metaphase 3. Anaphase 4. Telophase 5. Cytokinesis |
| Prophase – Mitosis | – Chromosomes become visible – Centrioles go towards opposite sides of cell – Spindle fibres form (from cytoskeleton) – Nuclear membrane disappears |
| Metaphase – Mitosis | – Chromosomes line up on equator – Spindle fibres attach to centromeres of chromosomes |
| Anaphase – Mitosis | – Centromeres split and sister chromatids separate and move to opposite poles |
| Telophase – Mitosis | – New nuclear membrane forms – Nucleolus reappears – Furrowing of cell membrane |
| Cytokinesis – Mitosis | – Cytoplasm divides to complete cell division |
| Interphase – Mitosis | – Periods between mitotic divisions – Chromosomes less organized; appear as chromatin – Divided into 2 gap and synthesis phases |
| Rough ER | – Transport materials from nucleus to cytoplasm – Protein are synthesized on ribosomes |
| Smooth ER | – Involved in synthesis and storage of non-protein molecules (ie lipids, carbs) |
| Golgi Apparatus | – Modifies, sorts, and packages proteins – Produces lysosomes and various secretory vesicles |
| Lysosomes | – Vesicles; originate from Golgi – Contain enzymes (Peroxisomes – oxidative enzymes used to removes toxins) – Intracellular digestion of food particles – Protects agaisnt invading microorganisms – Removes cellular debris |
| Vacuoles | – Membrane bound sac – Contains fluids or solid particles to be digested, excreted, or stored |
| Lysosomes + Vacuoles = ? | Phagosomes – aids in digestions of nutrients to gain nutrients |
| Mitochondria | – Powerhouse of cell – Makes ATP via electron transport chain – Divides independently through binary fission (without cell) – Contains its own strand of DNA |
| Structures of the Mitochondria | 1. Smooth, continuous out membrane 2. Cristae – folded inner membrane; contains enzymes and electron carriers of aerobic respiration |
| Chloroplasts | – In algae and plant cells – photoautotrophs (uses air to make carbon & sunlight for energy) – Oxygen produced as a by-product |
| 2 Structures of the Chloroplast | 1. 2 membranes – Smooth outer membrane – Folded inner membrane – thylakoids 2. Stroma matrix around thylakoids – Has its own genetic info, can divide without cell cycle |
| Cytoskeleton | – Helps provide support – Flexible framework of molecules |
| 6 Functions of the Cytoskeleton | 1. Anchors organelles 2. Provides support 3. Produces movement of cytoplasm 4. Important role in intracellular transport 5. Forms spindle fibres 6. Movement of the cell as a unit |
| Ribosomes | – Site of protein synthesis – Scattered freely in cytoplasm or with RER – Similar structure to prokayotic ribosomes but larger |
| Fungi | – Includes mold, mushrooms, and yeasts – Heterotrophs – from organic compound – Scavengers |
| Fungi – Structure | – Unicellular or multicellular – Cell walls contain chitin (instead of PG) – Can join together – colonies |
| Fungi – Reproduction | – Sexually or asexually – Spore formation (sexually) OR budding (asexually) |
| Fungi – environmentally (what are they and how do they get their nutrients) | – Live as saphrophytes/saprobes (scavengers/decomposers) – Nutrients through absorption – organic compounds |
| Human Fungal Pathogens (3 Classifications) | 1. Yeast – in body; like warmth 2. Mold – environmentally; like cold 3. Dimorphic fungi – very adaptable |
| Yeasts (reproduction? cellular?) | – Unicellular microorganisms – Asexual (budding – similar to binary fission) – Best in moist environment |
| Molds | – Multicellular microorganisms – Asexual – Develop characteristic hyphae – Hyphae grow to form a mycelium (e.g. white mold on tomatoe) |
| Hyphae | 1. Septate – divided/separate into distinct cell-like units 2. Coenocytic – no septal divisions |
| Asexual Reproduction – fungi | – similar to binary fission (for yeast) – molds reproduce by fragmentation (little pieces break off) of their hyphae and by spore formation |
| Asexual Spore Formation (2 types) | 1. Sporangiospores – form inside a sac (sporangium); spores released when sporangium ruptures 2. Conidia – produced at tips/sides of hyphae; pinch/break off and then travel |
| Sexual Reproduction – fungi | – When nutrients are limited – Can be dispersed/travel widely throughout environment by air, H2O, and other organisms – Germinates when good conditions |
| +mycelium and -mycelium =? (sexual reproduction) | = dikaryon; then divides by meiosis to end up with variations |
| What do the 2 forms of Dimorphic Fungi depend on? | – Grows in 2 forms; depends on the temperature |
| 2 Forms of Dimorphic Fungi | 1. Mold with septate hyphae @ 25 degree celsius (low) 2. Yeast in tissues @ 37 degree celsius (high) |
| Systemic Mycoses | – Infection through blood stream |
| Fungal Growth Requirements | – Heterotrophs – mostly saprobes/saprophytes (scavengers/decomposers) – Can be parasitic (needs host cell) – Aerobic – Some yeasts are facultative anaerobic (w/ or w/out oxygen) |
| 4 Different types of fungal infection diseases | 1. Superficial mycoses 2. Lutaneous mycoses 3. Subcutaneous mycoses 4. Systemic infections (inhaling then goes through bloodstream) |
| Superficial Mycoses | – Tineas = infection of epidermis – Waits for a weakened immune host – Usually direct contact (e.g. attacks melanocytes/pigments) |
| Cutaneous Mycoses | – Infections extend deeper into epidermis – Involves stratum corneum and occasionally upper dermis |
| Subcutaneous Mycoses | – Occurs after a puncture (poked with something that has fungus on it) – Fungus invades the deeper layers of the dermis |
| Systemic Mycoses | – Fungal infection which spreads throughout the body – Portal = respiration then bloodstream |
| Mycotoxins | – Chemical by-products from fungal metabolism – Ingesting contaminated food |
| Long term ingestion of Mycotoxins can cause 3 things | 1. Liver & Kidney damage 2. Gastrointestinal or gynecological disturbances 3. Cancer |
| Protozoa | – Kingdom Protists – Unicellular or colonial organisms – Contains major eukaryotic organelles (EXCEPT chloroplasts) |
| Structural Features of Protozoa | – Cytoplasm into 2 layers 1. Ectoplasm (clear outer layer involved in locomotion, feeding, and protection) 2. Endoplasm (granular inner layer w/ nucleus. mitochondria, and vacuoles) – No cell wall; but has cell membrane |
| Locomoter Appendages in Protozoa (3) | 1. Flagella 2. Cilia 3. Pseudopods – cytoplasm flows into 'fake feet' = migrates into diff directions |
| Nutrition of Protozoa (how do they get their carbon, what do they need, etc) | – Heterotrophic Organisms – Uses live cells of bacteria and algae – Scavengers – Some parasitic – Trophozoite stage = active feeding stage – no vegetative stage |
| Habitat of Protozoa | – In fresh and marine water, soil, plants, and animals – Converts to a resistant dormant stage when feeding/growth are harsh (go out into cyst until environment is better) |
| Virion | – Fully formed virus that's able to now establish infections in a host cell |
| Basic Structure of a Virus | – Capsid (protein coat) – Nucleic acid – DNA or RNA (single or double) |
| How do Viruses multiply? (general) | – By taking over a host's cells genetic material (since they're not living organelles) |
| Capsid (protein shell) + nucleic acid (genetic info) = ? | – Nucleocapsid |
| Do viruses always have an envelope? | – Not always |
| What are CAPSIDs made out of? | – Proteins called capsomeres |
| What are the 2 capsomere arrangements? | 1. Helical – like a tin can looking 2. Icosahedron – Diamond/spider looking one |
| How are the Icosahedron Capsules formed? | – 12 spaced corners – 20 triangular faces – 30 edges |
| How is the viral envelope formed? | – By budding through a host membrane |
| What's on the outside of a viral envelope? | – Glycoproteins |
| What do the spikes do on a virus? | – Viral attachment to host cell (remember it has lock and key) |
| What does the viral envelope do? | – Attacks – Protects nucleic acid from enzymes and chemicals outside of host cell – Infects viral DNA/RNA into host cell – Can also stimulate the immune system to produce antibodies that protect the host cell agaisnt future infections |
| What are the 2 atypical/complex viruses? | 1. Poxviruses 2. Bacteriophages |
| What are proxviruses? And its 3 features? (Think of hamburger shaped) | – Large DNA viruses that lack a capsid 1. Nucleoid – central disk structure, sorrounded by membrane and 2 lateral bodies 2. Lateral bodies – contains enzymes for viral replication (penetration) 3. Lipoproteins & Coarse fibrils – densed layer |
| What are Bacteriophages? | – Viruses that only infect bacterial cells (what allows bacterial cells for getting drug resistance – bc they pick up virus DNA) |
| What are the 2 structures of a Bacteriophages? | 1. Icosahedral Head – contains nucleic acid 2. Tail – Has attached fibres, sometimes surrounded by sheaths (for protection) |
| Genome | – Part of Nucleic Acid – Is sum of all genetic info (DNA/RNA – single or double) – Carried by nucleic acid |
| Viral Enzyme Functions (3) | 1. Polymerases – form large polymers (DNA or RNA) – attachment 2. Replicases – copy DNA 3. Reverse Transcriptase – allows the synthesis of DNA from RNA ase – enzyme |
| 6 Animal Virus Life Cycle | 1. Adsorption 2. Penetration 3. Uncoating 4. Replication 5. Assembly 6. Release |
| Adsorption (1st step) | – Cell membrane receptors specific to viral configurations (lock & key) – Host Range – limits virus of being able to cross over sometimes (from characteristics of cell) |
| Penetration (2nd step) | – Direct fusion of virus with host cell membrane (nucleocapsid released into cell's interior) |
| Uncoating (3rd step) | – Endocytosis – cell membrane engulfs liquid or solid material into a vacuole – Vacuole enzymes dissolve viral envelope and capsid uncoating nucleic acid (Into vacuole – then enzymes uncoat it) |
| Replication (4th step) | – Viral nucleic acids take over host cell's synthetic and metabolic machinery |
| Assembly (5th step) | – Nucleic acid strand inserted into empty capsid shell = nucleocapsid formation – Viral spikes added on when leaving/budding off |
| Release (6th step) | – Lyses = non-enveloped – Budding/exocytosis = get envelope from membrane when leaving |
| Replication/Multiplication of Bacteriophages | – Similiar to animal viruses but no uncoating phase; instead injected in (since its like a spider thingy) |
| Retrovirus – What do they do? | – Uses RNA as a template to produce viral DNA (as a template) – Has 2 copies of ssRNA & reverse transcriptase |
| Retrovirus Multiplication Cycle (4) | 1. Retrovirus penetrates host cell 2. After uncoating reverse transcription of the viral RNA produces dsDNA 3. New viral DNA is transported into host cell nucleus; integrated as provirus & then replicate 4. Mature retrovirus leaves, acquires envelope |
| What is a Morphological (Cytopathic) effect? | – Changes in the shape of a host cell caused by a viral infection |
| What are the 6 Morphological (Cytopathic) effects? | 1. Altered Shape 2. Detachment from tissue surface 3. Lysis 4. Membrane Fusion 5. Altered membrane permeability 6. Apoptosis (programmed cell death?) |
| What is a inclusion body? | – Compacted masses/debris of viruses or damaged cell organelles (DNA – nucleus; RNA – cytoplasm) |
| What are the 3 Host Cell's Damages? | 1. Physiological Effect 2. Biochemical Effect 3. Genotoxic Effect |
| What is the Physiological Effect? | – Addition of viral proteins into plasma membrane; changes of characteristics and/or functions leading to altered cellular activities |
| What is the Biochemical Effect? | – Inhibition or alteration of host cell's macromolecules (e.g. lipids, fats, carbs) |
| What is the Genotoxic Effect? | – Affects future generation – Genotoxic substances can damage host cell DNA – Teratogenic Effect – mutation – Potential start of cancer |
| What are the 5 Viral Infections? | 1. Abortive Infections 2. Lytic (cytocidal) Infection 3. Persistant Infections 4. Slow Infections 5. Transforming Infections |
| What is the Abortive Infection? | – When the virus can latch on, but cannot proceed further because the host cell is non-permissive (cannot reproduce) |
| What is the Lytic (Cytocidal) Infection? | – Infection of permissive cells which kill the host – Allows virus to hijack metabolic machinery |
| What are the 2 Persistant Infections? | 1. Chronic- productive but not lytic 2. Latent – has a dorment stage/ like chicken pox and turburculosis) |
| What is a Slow Infection? | – Prolonged incubation period |
| What is the Transforming Infection? | – Alters cell properties |
| What is a Oncogenic Transformation? | – Genetic modification of cell proliferation control – tumour cells |
