Prokaryotic Cell Chatacteristics Flashcards
(83 cards)
0
Q
More sophisticated *
A
Adaptation capabilities
Cell envelope structures
Mechanisms for motility an adhesion
1
Q
Compared to eukaryotic (human) cells 8 things
A
Ancient (survive more) Smaller (needs less) Simpler (components are eat to replace) More abundant Don't have nucleus Don't have organelles (makes targeting reactions by drugs very difficult) Have a single chromosome(simple) More sophisticated*
2
Q
What is a bacterium? (Singular)
A
Mo whose body is a prokaryotic cell
3
Q
Components of prokaryotic cells 3 main classifications
A
Appendages
Cell envelope composition
Within the cytoplasm
4
Q
Appendages
Definition
Parts
A
Components which project from the body
Flagella
Pili
Fimbrae
5
Q
Flagella (external)
- present in
- Purpose
- Composition
A
Preset in bacilli and spirilla
- motility; chemotaxis; phototaxis
- Body(attaches) hook (gives power for movement) filament (allows movement to be completed)
6
Q
Examples of bacterial sp. by specific # and arrangement of flagella
4 types
A
Monotrichous: 1
Lophotrichous: 2
Amphitrichous: many on sides
Peritrichous: all over
7
Q
Chemotaxis
A
Ability to detect chemical
Moves toward movement if +
Moves away from movement if -
8
Q
Methods of establishing if an mo is motile
A
Semisolid stab
Hanging drop
9
Q
Flagella (internal or periplasmic) not an appendage
- location
- Where specific?
- Action
A
- In spirochetes
- Located between within the cell envelope (between the cell wall and the cell membrane)
- Offer more variation and precision in movement
10
Q
Pili (plural)/pills (singular)
- Present
- What is it
- Origin
- Action
A
- Present only in gram -
- A long, tube-like structure
- Originates from one bacterium and attaches to another.
- Used in process of conjugation (a type of mating = presentation. A copied or excited piece of DNA (plasmid) from a donor bacterium is transferred to a recipient bacterium
11
Q
Fimbrae
A
Bristle-like proteins
Stick out
All over surface
Linked to process of infection
12
Q
Cell envelope composition
A
Glycocalyx (slime layer/capsule)
Cell wal
Cell membrane
13
Q
Glycocalyx
- what is it?
- Composition
- Thickness
- types
A
- outermost layer of envelope
- Composition varies (mostly polysaccharides)
- Thickness varies
- Smile layer and capsule
14
Q
Slime later of glycocalyx
A
Loosely bound
Prevents loss of water and nutrients
15
Q
Capsule layer of glycocalyx
- Bound ?
- Purpose?
- Examples
A
Tightly bound
Sticky for adherence (protection against WBC)
Ex: streptococcus pneumoniae, Haemophilus influenzae, Bacillus anthracis.
16
Q
Cell wall
- Component
- Purpose
A
- Most important component: peptidoglycan
2. Maintains shape (survival) of mo. Prevents bursting of collapsing.
17
Q
Cell membrane
- composition
- Amount
- Purpose
A
- Varies (resemble that found in human cells)
- Can have more than one (often)
- Varies (ex: controlling transport)
18
Q
Within cytoplasm parts
A
Chromosomes Plasmids Ribosomes storage bodies Endospores
19
Q
Chromosomes in cytoplasm
A
One; loose (no nucleus) Looped or linear DNA coiled 250,000 genes Genetic material used for many purposes sulfa drugs kill DNA
20
Q
Plasmids within cytoplasm
What is it?
Intended for what?
Purpose
A
A copy of a small segment of DNA or excised segment of DNA
intended for donation
Few bacteria can do this (gram -)
To impart resistance and to improve abilities (not linked to resistance)
21
Q
Ribosomes within cytoplasm
A
Site of protein synthesis
Smaller and less dense than eukaryotic (70 against 80 Svederg)
Useful in the ID of a mechanism
22
Q
Storage bodies within cytoplasm
A. Inclusions
A
Stores basic nutrients
Dedicated: 1 type of nutrient. Ex: lactose
General: more than 1 type of nutrient. Ex: water, fat and carb
24
Q
Storage bodies within cytoplasm
B. Granules
A
Variety of purposes
Ex: gas granules (allows floating)
Ex: pigment granules
25
Endospores within the cytoplasm
created?
types?
Requirement?
created by the process of Sporulation (not reproduction)
Bacilli formers and Bacilli-nonformers
Requirement: begin only when they near death
26
Sporulation process
| 5 steps
1. Replication: copies of chromosome made (200-6000)
2. Segmentation of envelope
3. Each chromosome is wrapped in a piece of envelope
4. Release of spores. Light in weight, go to a safer place
5. Spores grow to size of original
SELF PRESERVATION
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Size of bacteria
Range
Implications
Range: 0.2 um (bacilli, can hide) to 250 um (spirochetes, eat more, damage)
Implications: The smaller the easier to hide and the more difficult to recognize and attic
28
Shapes of bacteria
| 6
1. Coccus (singular): round, more surface area, more abcs can enter the body at the same time
2. Bacilus (singular) penetrate
3. Coccobacilus: adjust to environment
4. Vibrio: D used for attachment to structures
5. Spirillum: (spirilla for pl) penetrating action (damage deep organs
6. Spirochete
29
What is pleomorphism?
cause
ex
classified
"many shapes" a species which can have more than one shape. Can be born one thing and become another.
cause: nutrition; heredity
Ex: Rhizobiun; corynebacterium
Classified as: primary shape but has pleomorphism to__
30
Arrangements of bacteria
| 8
Some bacteria are independent but most live in arrangement.
1. Diplococci: 2 cocci. Manage needs well (shape) Portions that are not exposed are protected by partner. Need more potent dose of med.
2. Tetrads: cocci 4. More safety for them
3. Sarcinae: cocci in multiples of 8. Shapes vary but flower shapes are common: rose)
4. Streptococci: Serial arrangement (significant or limited) 0000000000000000
5. Staphylococci: Irregular shaped group. Deep circular wound (irreg) 00000
00000
6. Diploacilli: 2 bacilli //
7. Streptobacilli: -----------
megacterium: big, larger
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Identification and Classification or bacteria
grouping bacteria according to common features
32
ID of bacteria
| 6
Usually based on:
1. Morphology
2. Gram status
3. Presence of specific structures (flagella, cilia)
4. Colony characteristics (streak: size, shape, elevation, color, margin)
5. Biochemical reactions
6. Nucleic acid composition (unique; best to ID)
33
Ex of bacteria with unusual traits
| 2 classifications
1. Obligate intracellular parasite (must live inside of cell) no benefits, host is harmed.
2. Cell wall deficient: don't have a cell wall
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Obligate intracellular parasite
Rickettsias and Chlamydias
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RIckettsias
Mammal host to arthropod (lice; ticks)
causes Rocky mountain Spotted Fever
Typhus tick----destroys CT
36
Chlamydias
eye infection (retinal cells)
STD (reproductive cells)
Ornithosis (bird infection , inhale)
37
Cell wall deficient
Mycoplasmas: very large
Sterols: Alcohols. Release alcohol to whatever is making it uncomfortable
Atypical Pneumonia: Alveoli coated with alcohol---breakdown of alcohol---blood in lungs---infection in blood
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Photosynthetic bacteria
Capable of synthesis
Cyanobacteria; Green and Purple Sulfur Bacterial; Myxobacteria
Fruiting bodies (where photosynthesis takes place)
39
Photosynthesis
CO2+H20---(sunglight)---> carb+ O2
then carb---mo---energy
40
Bergey's Manual of Systemic Bacteriology
Contains all known facts about all known bacteria
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Classification
Evolutionary (q feature of mo is considered in classifying). Phenetic relationships (use morphology only in classifying)
42
Nutrition
Essential vs nonessential
Metabolism
Nutritional types
43
Essential vs nonessential nutrition
Essential (environmental): has to come directly from the environment
Nonessential (non environmental): Can be made from an essential. Cant get from environment directly.
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Metabolism
Chemical reactions
| N (Nutrient)---P (product) x---(enzyme)---> Y
45
Nutritional types
Autotrophs: derive energy from sunlight or inorganics
Heterotrophs: derive energy from organics (worse for us, grow in body)
46
Types of Autotrophs
Phototrophs
| Chemoautotrophs
47
Types of Heterotrophs
1. Photoheterotrophs: Organic---sun---> Energy (needs sunlight)
2. Chemoheterotrophs: organic---inorg--> E (needs an inorganic. (Keep inorganic away to kill it)
3. Saprobe: takes organic chemical from dead to make E
4. Parasite: organic---E. Harms, eats and reproduces and benefits
48
Environmental Influences
| 4
temp
oxygen
pH
Pressure
49
Temperature (environmental influence)
'cardinal temp'
minimum: lowest temp at which it will grow (reproduce)
maximum: highest temp at which it will grow
Optimum: Better temp for reproduction
Optimal temp: psychophile, mesophile and thermophile
50
Psychophile
Opt. below 15 C
grows at 0
won't grow at 20 so <20
51
Mesophile
37-40 C
opt 20-40 some are thermo duric
Most human pathogens 30-40
52
Thermophile
>40 C
| Paper says >45
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Obligate aerobe
Needs High Oxygen
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Facultative anaerobe
Preferes 02. It can live anywhere
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Microaerophile
Requires low levels of O2. Anything other will kill it
56
Obligae anaerobe
Must have 02 free environment. No 02
57
pH
alkaline is high pH
| Acidic is low pH
58
Pressure requirements
Typically isotonic or hypotonic
halophiles
osmphiles
barophiles
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Isotonic
Solvent and solute are the same amt inside and outside
60
Hypotonic
Solute is smaller than solvent inside the cell
61
Halophiles
Typically exist in an environment that has halogens (high)
Tends to lose water from internal environment if in marine environment.
Some are Impermeable and live: envelopes prevents water from coming out
62
Osmophiles
swells because it takes water from the outside
63
Barophiles
Pressure outside mo is greater than inside. Pressure deserts envelope.
64
Growth requirements
Growth is increase in amt of bacteria in a population
| A parent undergoes binary fission to produce 2 daughter cells.
65
Binary Fission
Something breaks into 1 (Asexual)
66
Rate of growth or generation time
the amt of time is takes for binary fission to occur (1 cycle)
short: 5 min
long: 30 days
Pathogens: fast (20-30 min for food pathogens
67
Growth curve
```
Stages in normal growth. Plot which represent the behavior of a mo in a particular location in the human body.
lag phase
log phase
stationary growth phase
death phase
```
68
Lag phase in growth curve
Little growth because few cells are adjusting to new environment, enlarging, synthesizing.
Tx should happen here.
69
Log phase in growth curve
Period of max growth. All conditions are optimum.
70
Stationary growth phase in growth curve
cell death: cell birth
Depletion of nutrients (some are dying and some are fine)
Excretions pollute
Completion
71
Death phase
Decilne
| Drugs and immune system killing mo
72
Practical applications of growth curves
| ex 1,2 and 3
1. Antimicrobial agents (heat; disinfectant) disrupts these phases (lag phase)
2. Understanding the progression of an infection. If you have a previous growth curve on record for the bacteria in the location you can predict symptoms, damage and timing.
3. Industry must use chemostat (instrument that keeps track of body conditions when an infection is happening)
73
Methods of determining growth
turbidity: too rough (last choice) accuracy?
Direct cell count: counting one by one on microscope. Accuracy
Coulter counter: sample, best ID (you know the size of the mo) volume (1ml) particular. Filters catch food with other drugs. Clamps to make sure only one goes at a time. Spectrophotometer. Spec 20. Read out, printable, records # of bacteria pass by (A%)
74
Metabolism of baceria.
| Types of enzymes
exoenzymes
endoenzymes
constitutive enzymes
induced enzymes
75
exoenzymes
released by mo. Degrades a substance and the product (smaller) Some drugs destroys these.
AB----> A+B
76
Endoenzymes
Regular enzyme inside the mo (metabolism)
| Preventing mo to do what it needs to survive (drugs)
77
Constitutie enzymes
Produced 24/7. Central to metabolism. Involved in very important chemical reactions within the mo
78
Induced enzymes
Produced only when needed. Opposite of consitutive
79
How enzymes can be controlled
Competitive inhibition
negative feedback
allosteric inhibition
enzymes (synthesis) repression
80
competitive Inhibition
A+B--enz--AB down. Death of mo.
Drug: dake substrate (Fake B)
Bf
81
Negative feedback
A+B---AB drug ABf.
| Not enough real AB made: mo dies
82
Allosteric inhibition
the reaction AB---AB. the alloesteric enzyme as product builds it. Atthes to allosteric site, then the active site shuts down
83
Enzymes (synthesis) repression
Shuts down product site
| RER---Enzyme
