TEST 1 Flashcards

Question

VIRUSES Type of cell? Classified by? Shapes Survive by?

Answer 1

Acellular CLASSIFICATION: Capsid- DNA or RNA surrounded by protein coat Enveloped- capsid encased in lipid membrane \*technically not living, depend on hosts cell to reproduce

Answer 2

PASTEUR 1861 - proof of microbes in the air and introduces **_biogenesis_** \*Sterile media in a closed environment failed to produce life Heat can kill microbes - forms **_aseptic technique_** **_Developed pasteurization = lower heat longer periods = increased shelf life_**

Answer 3

JENNER 1798: Creates smallpox vaccine \*infection from cowpox prevents smallpox

Answer 4

SNOW 1854 - mapped cases of cholera to water and stopped epidemic

Answer 5

LISTER Professor in Scotland, amputations Phenol - kills microbes, infections decrease

Answer 6

KOCH Showed disease caused by microbe 1876: Koch's postulates 1. Same organism present 100% of time 2. Isolate & make sure its the only organism 3. Infect healthy animal 4. Observe same symptoms 5. Must see only same organism = CAUSE

Answer 7

FLEMING 1928: Discovers antimicrobial agents \*accidentally discovers mold can inhibit bacterial growth -penicillin

Answer 8

WATSON, CRICK, WILKINS, FRANKLIN 1953 - determined structure for DNA \*franklin actually did expiermnent

Answer 9

**Emerging and reemerging diseases** - the fast pace of travel/movement **Increasing antimicrobial resistance** - overprescribed antibiotics **Climate change** - change habitats and species move to new regions **Humans** - intentional weaponizing of biological agents

Answer 10

Thick tightly bound glycocalyx on prokaryotes The thin loosely bound glycocalyx on prokaryotes

Answer 11

Monotrichous - 1 filament, polar Peritrichous - Filaments all around cell Lophotrichous - 2 or more filaments on same side Amphitrichous - Multiple filaments at each end Atrichous - no flagella present

Answer 12

Phototaxis - movement based on light Taxis - movement towards or away from stimulus Chemotaxis - movement based on chemicals

Answer 13

PASSIVE TRANSPORT- move by concentration gradient * *Osmosis** - water * *Diffusion** - non-water molecules * *Faciliated diffusion** - uses transporters (permeates) ACTIVE TRANSPORT - required energy **Group translocation**- substance is modified as it crossed over the membrane so new substance is impermeable

Answer 14

Osmotic pressure - pressure needed to stop the flow of water across a membrane Isotonic- concentration same inside and outside of the cell Hypotonic - concentration of solutes lower outside of cell Hypertonic - concentration of solutes higher outside of cell

Answer 15

Prokaryotes **_Plasmid_** - carry genes for antibiotic resistance, toxin tolerance and enzyme production. Can be transferred from one bacteria to another **_Ribosome_** - Protein synthesis \*Prokaryotes have 50S+ 30S = 70S Eukaryotes have 60S + 40S = 80S **_Endospores_** - resting structures formed by bacteria when living in an inhospitable environment. **_Sporulation_** - the process of making a spore Germination - process of returning a endospore back to vegetative state

Answer 16

Peptidoglycan - bacterial cell wall - carbohydrate backbone composed of alternating NAM and NAG. Interlaced with peptide cross-bridges Mordant - a substance, typically an inorganic oxide, that combines with a dye or stain and thereby fixes it in a material.

Answer 17

**_Bacillus -_** single rods Diplobacilli - joined at ends Streptobacilli - chain Coccobacilli - oval shape, single bacilli **_Coccus -_** Sphere Single cocci - single sphere Diplococci - pairs Streptococci - chain like Tetrads - groups of 4, square Sarcinae - groups of 8, cube Staphylococcus - grape like clusters **_Spiral_** - twist Vibrios - single, curve or bent Spirilla - corkscrew. Rigid Spirochetes - helical, flexible

Answer 18

**Glycocalyx** - sticky polysaccharides and protein. Protection from the environment and macrophages adherence may provide nutrients **Flagella** - long filamentous appendages. Motility - rotate like a propeller. Hook, filament and basal body **Axial filaments** - unique to spiral bacteria. Cause bacteria to rotate resulting in motion **Pili/fimbria -** short thin appendages, mostly on gram - and some +. adhesion to surfaces, motility and sex. Cell to cell conjugation - method of transferring DNA

Answer 19

Composed of a polymer called peptidoglycan \*carbohydrate backbone composed of alternating NAM (N-Acetylmuramic acid) and NAG (N-acetyl glucosamine) . NAMS contains 4 amino acid side chains The backbone is interlaced with peptide cross-bridges between the peptide side chains FUNCTION - maintain shape, protection from physical and osmotic lysis

Answer 20

Gram + cell walls are THICK w/ multiple layers of peptidoglycan \*also contain teichoic acids = regulate the movement of cations & excessive cell wall breakdown Gram - cell walls are THIN sometimes only 1 layer of peptidoglycan \*have outer layer = lipopolysaccharide - Sugar as antigen and Lipid A as endotoxin shock Also contains pores to allow molecules to mvoe

Answer 21

1. first heat fix bacteria to glass micro slides 2. apply primary stain - crystal violet for 1 min 3. Rinse - all cells purple 4. Add grams of iodine for 1 min \*iodine causes CV to crystalize in cells becoming trapped 5. Rinse excess iodine away 6. Decolorize cells with acetone alcohol \* this will attempt to pull CV out of cells \*Thin wall will present in gram - cells and allow dye to flow out/ gram + will keep it in 7. Apply a counterstain, safranin for 1 min Gram + will appear purple Gram - will appear pink

Answer 22

**Lipopolysaccharide** - gram negative -outer membrane & contains O antigen - Sugar acts as antigens Lipid A - endotoxin - causes endotoxic shock **Lipoteichoic acid -** gram positive cell wall & function as regulation of movement of cation & protection from cell wall breakdown

Answer 23

Mycoplasma - lack cell walls, sterols in their membranes protect from lysis Mycobacterium - thick cell walls that contain mycolic acid causing them to be waxy. unable to stain

Answer 24

**_Plasma_** **_membrane_** - encloses cytoplasm/ selectively permeable **_Cytoplasm_** - Fluid component of the cell. mostly water **_DNA_** - aggregates in nucleoid or nuclear area (not surrounded by membrane) CIRCULAR & attached to plasma membrane **Ribosomes** - Protein synthesis - 70S

Answer 25

**Flagella** - beat in a wave pattern - large 200nm, long & few in number **Cilia** - short hair like, high in number **Microtubule** - makes up cilia and flagella in a 9+2 format \* long hollow tubes of protein called **_tubulin_** / flexible skeleton

Answer 26

**Endocytosis** - how cells engulf larger particles **Phagocytosis** - pseudopods surround particles and engulf **Pinocytosis** - aka cellular drinking, cell folds in, creating a divot and folds around the area **Receptor-mediated endocytosis** - virus binds to receptor initiating similar to pinocytosis

Answer 27

**Chromatin** - a thread-like mass of protein and DNA when not replicating **Organelle** - membrane-bound structures **Histones** - proteins that keep DNA bound and function to regulate transcription **Nucleoli** - within nucleus, 1 or more spherical bodies, sites of rRNA synthesis

Answer 28

**Cristae** - folds in inner membrane of mitochondria **Matrix** - fluid-filled space in inner membrane of mitochondria **Nuclear pores** - allows access to nuclous / DNA **Grana** - stack of thylakoids **Thylakoids** - membrane sacs in chloroplasts where chlorophyll

Answer 29

Prokaryotic developed first -develops a primitive nuclear membrane to protect DNA - Big bacteria engulfed small bacteria - Small bacteria lost their DNA. relied on large bacteria - Reproduced with small in large bacteria - 2 eventually became indistinguishable **_Evidence_** - mitochondria & chloroplasts same shape and size as bacteria, circular DNA, reproduce independently of host cell, ribosomes 70S

Answer 30

Prokaryotic VS Eukaryotic 0.2-2 um - 10-100um No nuclear membrane - true nucleus No or few organelles - organelles Flagella - 2 protein - complex Glycocalyx capsule - present in some that lack a cell wall Cell wall - complex - simple Plasma membrane - carb & lacks sterols - sterols& carbs

Answer 31

P vS E Cytoskeleton - Cytoskleton (microfilaments, tubules) Small - larger circular, lack histone - linear, histone binary fission - mitosis non, transfer DNA only -- meiosis

Answer 32

Require living host to multiply

Answer 33

Contain a single type of nucleic acid, DNA or RNA Contain protein coat that surrounds nucleic acid Multiples inside living cells by using the cells' machinery causes specialized structures that can transfer the viral nucleic acid to other cells

Answer 34

the protein shell of a virus particle surrounding its nucleic acid. Capsid is surrounded by a lipid bilayer that contains proteins. Usually derived from host cells membranes - contains spike protiens

Answer 35

a virus that infects and replicates within bacteria and archaea

Answer 36

Host range - the range of cell types and host species a virus is able to infect. Tissue tropism - the ability of a given virus to productively infect a particular cell

Answer 37

**Lytic** - occurs when a virus has infected a cell, replicated new virus particles, and bursts through the cell membrane. **Lysogenic** - a virus that specifically infects a bacterium, achieves the manufacture of copies of its (DNA ) genetic material by integrating the viral DNA into the DNA of the host bacteria. **Plaque** - a clear area on an otherwise opaque field of bacteria that indicates the inhibition or dissolution of the bacterial cells by some agent, either a virus or an antibiotic.

Answer 38

deliberate application of phages to kill bacteria in infected tissue \*target bacteria cells and leave host cells alone \*drawback - phages are foreign and will be cleared from the immune system in 7-10 days

Answer 39

a protein produced by bacteria that cleaves DNA at specific sites along the molecule. In the bacterial cell, restriction enzymes cleave foreign DNA, thus eliminating infecting organisms.

Answer 40

**Cytopathic effects** - structural changes in a host cell resulting from viral infection. \*diagnostic tool **Cancer** - Unregulated cell division **Oncogene** - A gene that is a mutated (changed) form of a gene involved in normal cell growth **Oncogenic virus** - viruses that cause or give rise to tumors

Answer 41

**Acute infection** - simplest/most common - triggers immune **Latent infection -** remains in host for long periods **Persistent infection** - disease progresses, immune systems fails

Answer 42

**Structure** - Nucleic acid, Capsid, envelope **Morphologies** - _Helical_ - _Polyhedral_ - many-sided (20 faces, 12 corners) _Enveloped_ - Capsid covered by envelope, spherical _Complex_ - complicated structures. IE Bacteriophage

Answer 43

Grouping based on the nucleic acid sequence as well as structure Grouped into Family and genus Virus family end in - Viridae Virus genus end in - Virus

Answer 44

**_Host range_** - which organisms a virus can infect - limited in number. Mediated by attachment proteins **_Tissue tropism_** - availability of virus receptors

Answer 45

Mix bacteriophages with host bacteria and nutrient agar \*bacteria in the area of the virus are destroyed \*Area of lysis is called plaque

Answer 46

* *_Lytic_** - 1. Attachement/absoprtion 2. Penetration 3. Biosynthesis 4. Maturation/assembly 5. Release = cell death **_Lysogenic_** - 1. Attachment 2. Penetration 3. Phage DNA integrates with bacterial chromosomes by recombination 4. Produces normally 5. Occasionally lytic if environment is bad 5.

Answer 47

Whole animals Cultivated in embryonated eggs Cultured in cell culture in the lab

Answer 48

RFLP - small differences in a genome are detected to ID an organism PCR - a small region of nucleic acid is replicated, found only in virus and look to see if it matches the person

Answer 49

**Mycology** - the scientific study of fungi. **Thallus** - major stock or body of molds **Hyphae** - long thin filaments that make the thallus **Septate hyphae** - Contain crosslinked walls **Coenocytic hyphae -** one continuous cell with multiple nuclei

Answer 50

**Vegetative hypha** - responsible for nutrient absorption **Aerial hypha** - responsible for reproduction \*contain spore **Mycelium** - the vegetative part of a fungus, consisting of a network of fine white filaments (hyphae). **Dimorphism** - can grow as either yeast or molds

Answer 51

**_Conidosphore_** - Asexual = not enclosed by a sac \*form at the end of a stalk-like structure called = **Conidiophore** **_Sporangiospore_** - enclosed by a sac \*located at end of aerial hyphae called **Sporangiophore**

Answer 52

**_Mycosis_** - fungal disease **_Dermtophytes_** - fungi that affect epidermis **_Keratinase_** - produced by dermatophytes - degrades keratin

Answer 53

**_Mycology_** - study of fungi **_Importance to medicine_** - increasing nosocomial infections & problematic for immunocompromised **_Importance to agriculture_** - all plants rely on mycorrhizal for nutrients & devasting pathogens to commercial crops

Answer 54

Fungi are: Eukaryotic. have sterols in membrane Lack peptidoglycan Heterotrophic Sexual and asexual

Answer 55

**_Budding_** - bud forms on the surface of the cell. Can produce up to 24 daughter cells **_Fission_** - cell elongates, nucleus/organelles replicate, cell pinched off in middle and 2 daughter cells are produced

Answer 56

37 = yeast like 25 = mold like Regulation is also depending on Co2

Answer 57

Fungal spores Reproductive Undergo sexual recombination Do not provide protections

Answer 58

The result from sexual reproduction, 3 phases **_Plasmogamy_** - Donor cell penetrates recieptent cell **_Karyogamy_** - both nucleus fuse = diploid zygote **_Meiosis_** - diploid give rise to haploid