MicroBiology Flashcards
(183 cards)
1
Q
How are trees of life generated?
A
Comparing nucleic acid sequences, specifically rRNA as present in all life
Also has a range of rates of secondary structure and double stranded and single stranded region, useful for making primers
2
Q
What’s a monophyletic group or clade?
A
It’s a group of organisms that consists of all the descendants of a common ancestor
3
Q
What’s a taxon?
A
Any group of species that we can designate a name
Multiple is taxons
4
Q
What’s a node?
A
Split in branch from one lineage into another
5
Q
Root node?
A
Common ancestor of all taxa in the tree
Point of earliest split in the tree
6
Q
Root?
A
Branch leading up to the root node (i.e. the common ancestor of all taxa in tree)
7
Q
What are the 3 domains?
A
Bacteria
Archaea
Eukaryota
8
Q
What is mutational saturation?
A
Where a site changes so fast difficult to tell what is a reversion (in Analysis)
9
Q
Challenges on finding out more about Archaea?
A
Difficult to culture in lab
10
Q
What is metagenomics?
A
Sequence everything approach (mixtures of species/genes), then reconstruct genomes, or segments of genomes.
11
Q
What’s a virus?
A
Infetive agent that typically consists of a nucleic acid molecule in a protein coat
12
Q
3 theories on how viruses evolved?
A
Viruses are escaped portions of cellular organisms
Viruses are extremely derived and reduced cellular organisms
Viruses are relics from a pre-cellular world: Self-replicating units in the ancient virosphere may have gained the ability to form membranes and cell walls, leading to evolution of the three domains of life.
Or a mixture of all 3
13
Q
Different morphologies of bacteria?
A
Coccus (sphere shaped)
Rod
Spirillum (like kidney bean)
Spirochete (coiled)
Budding and appendages bacteria (have stalk and hypha)
Filamentous bacteria (very long and thin)
14
Q
Features of bacterial cell size?
A
Have a large surface area to volume ratio
Leads to faster uptake of nutrients
And more cells per given resource, more cells mean more evolution which drives evolution
15
Q
Features of bacteria phospholipid bilayer?
A
= glycerol + 2 fatty acids + phosphate group
Strengthened by molecules called hapanoids, which is essential for mycoplasmas
In Bacteria and eukaryote ester bond in bilayer, whereas as ether bond in archaea
Archaea bilayer is continuous so much stronger (no small gap in middle)
There are proteins in membrane for transport
16
Q
Feature of bacterial cell wall?
A
Made up of Peptidoglycan (2 sugars and some amino acids)
Occurs in90% gram + ves, bacteria and 10% in gram -ves bacteria
17
Q
How is outer membrane not symmetrical to inner in gram negative bacteria?
A
The outer isn’t just phospholipids
Large polysaccharide component
18
Q
How to count bacteria?
A
By culture, dilute to an extent so colonies can be counted then multiply up
Only tells you have many are living, not necessary all of them
So can count by them a light microscope as well, normally with an oil immersion lens
19
Q
Equation for resolution of a lens?
A
R = (0.5 x wavelength) / numerical aperture
20
Q
Difference of gram positive and negative bacteria and Features of the gram stain?
A
Gram positive bacteria have large petiodglycan cell wall above plasma membrane
Where as gram negative have 2 bilayer around peptidoglycan cell wall
Need to add notes on how to do the gram stain
Gram positive remain purple
Gram negative go pink
21
Q
Cell surface structures of bacteria?
A
Capsules
Fimbriae and pili
Flagellar
22
Q
Features of capsules?
A
Can be polysaccharide or protein or both
Play a role in pathogenesis and biofilm formation
23
Q
What is biofilms formation?
A
Predominant bacterial phenotype in nature (their stain)
Form on solid substances with moisture
On soft tissues in living organisms
At liquid air interfaces
24
Q
What are endospores?
A
Bacteria become them when they go into dormant stage of lifecycle
Very resistant to lots of things
25
How to antibiotics generally work?
Targeting processes of bacteria which don't have an effect on the eukaryote cell
26
Naturally occurring antimicrobials are?
Naturally occurring antibiotics
27
Modification of natural antibiotics results in?
Semi-synthetic antibiotics
28
What are ahminoglycosides and what aren't they used today?
Antibiotics that contain amino sugars bonded by glycosidic linkage
Not used today as high neurotoxicity and nephrotoxicity
Only used when other antibiotics fail
29
What are macroslides?
Contain lactone rings bonded to sugars
Broad spectrum antibiotic that targets the 50S subunits of ribosome
30
What are tetracyclines?
Contain 4 rings
Widespread medical use in humans and animals
Broad-spectrum inhibition of protein synthesis
Inhibits functioning of 30S ribosomal unit
31
Example of a synthetic anti microbial drug?
Quinolones - causes the inhibition of DNA gyrase
Binds to the A subunits of DNA gyrase
Resistance mediated by decreased binding
32
What are the most produced antibiotics and features?
B-Lactam
Primarily effective against gram positive, but can be modified synthetically to target gram negative
Includes penicillin
Target cell wall synthesis§
33
Why are B-lactams effective against gram positive bacteria?
Because it's mainly cell wall, whereas gram negative cell wall is protected by both phospholipids bi layers
34
What are bacteriocidals?
The bacterial cells still remain but they are no longer viable, so can still them under microscope but they are no longer causing disease
35
What are bacteriolytics?
Kill all bacterial cells via lysis but disturbing cell wall so no longer visible under a microscope
36
Features of vancomyosin?
Inhibits cell wall biosynthesis
But has poor bioavailability
Used for treatment of C. difficile
37
Features of methicillin?
Inhibits cell wall biosynthesis like penicillin
However not used anymore as caused a lot of antibiotic resistance
38
Ways in which a bacteria can be antibiotic resistant?
Lacks the structure the antibiotic inhibits
Organism is impermeable to antibiotic
Organism can inactivate the antibiotic
Organism may modify the target of the antibiotic
Organisms may be able to. pump out the antibiotic (efflux)
39
What does antibiotic resistance spread through?
R plasmids
Consist of a resistance transfer factor that enables conjugation
Contains gene conferring resistance
40
Step 1 of a gram stain?
Differentiates between a gram positive and a gram negative bacteria
Performed on a smear sample, which is made by spreading the bacterial cells on a microscope creating an even layer. They are then killed and fixed to the slide
Crystal Violet is applied first, it dissociates into CV+ and Cl- ions, these are taken up by both cell types, the CV+ ions bind and stain the negatively charged components of the bacterial cell wall
After one minute crystal violet washed off with water
Both types of cell are now purple
41
Step 2 of a gram stain?
Gram's iodine is now used to fix the dye within the cells it is taken up by both gram negative and gram positive
It forms a complex with the CV+ ions, which are in soluble in water so they become trapped in the cell
After one minute excess gram iodine Is washed off
42
Step 3 of gram stain?
Add alcohol/acetone and rinse with water, to decolourise the sample
The crystal violet dye is removed from gram negative bacteria, but not from gram positive bacteria
This occurs as in gram negative bacteria the lipids that make up the outer membrane are dissolved, in both positive and negative the peptidoglycan layer is dehydrated, the gram negative only left with thin peptidoglycan outer layer so the dye leaks out, but in gram positive the peptidoglycan layer is thick enough to retain it
So after this step gram positive purple, and gram negative is colourless
43
Step 4 of gram stain
Stained with safranin which is taken up by both cell types and binds to the lipid cell membrane
Washed off with water after 45 seconds
Gram negative is now pink, and gram positive is now purple, so can now look at both of them under a microscope
44
What does taxonomy do?
Identifies the relationships between groups of organisms
Can be used to identify novel or previously unknown organisms
Provides universal language of classification between scientists
45
What are taxa?
Catergories of organism
46
What is gram positive bacteria divided into?
Low G + C = Firmicutes
High G + C = Actinobacteria
47
Why is so much known about gram positive and gram negative bacteria?
Easy to culture
48
What is an ecosystem?
Sum of all organisms and abiotic factors in a particular environment
49
What is symbios?
Mutualism and Commensalism
50
What is mutualism?
Both species benefit
51
Commensalism?
One species benefits, the other is neither harmed or benefited
52
Syntrophy
Two or more organisms catabolising a nutrient that can not be catabolised by one on its own
53
Species richness
the total number of species present in an ecosystem
54
Species abundance
the proportion of each species in an ecosytem
55
Why do bacteria grow so much slower in environment?
limiting resource of nutrients
Growing in mixed populations
Distribution of nutrients
56
steps in formation of a root nodule in a legume infected by Rhizobium?
The plant roots secrete a chemical called flavonoids that stimulate the growth of Rhizobia in soil, they end up growing to high densities around the root
The chemicals also induce the expression of bacterial genes, Rhizobium carry a large plasmid called the Sym, which carries nod genes which are involved in nodulation
Flavanoid binds to product of the nod gene, which binds upstream and promotes transcription of more nod genes which Creates a nod factor
These then bind to the root hairs, and create an infection thread and enter the root cells
Generate bacteroids in the cells which do nitrogen fixing
57
Are viruses living?
NO
58
What can viruses infect?
Bacteria, Archaea and Eukarya
Virophages can also infect viruses
59
2 types of verions?
Naked virus
Enveloped virus (encapsulated)
60
What are bacteriophages?
Viruses that infect bacteria
61
How do bacteriophage work (lytic pathway)?
Virion attaches to host cell
Penertrate/inject into it
Hijack cells DNA, and synthesise nucleic acids and proteins
Assemble and package them
Release the new virions to infect more cells
62
What is the lyosogenic pathway?
Virus attaches to receptor on bacterial cell wall and injects it's DNA into the cell.
The protein coat remains outside the cell while the phage DNA inside quickly forms into a circle
Whether the phage takes the lytic or lyosgenic pathway depends on which genes dominate
If a gene called c1 (also called the lambda repressor gene) dominates, the phage will progress into the lysogenic pathway
If a gene called cross dominates the phage will progress into the lytic pathway
In this battle, RNA polymerase comes in and recognises Pl and Pr promoters (left and right), this will cause protein N and protein Cro to form
However N is an anti terminal, meaning c11 and c111 and Q will be transcribed as RNA polymerase doesn't stop
Q is another anti terminator allowing transcription of while chromosome and the production of proteins and vision for lysis this is the lytic pathway
However, for the lyosgenicpathway to occur the c11 protein can bind to a promoter region called Pe, causing the transcription of c1, c11 can only do this if protected by c111 from proteases
On the right operator region, there are 3 binding sites c1 can bind to, when it binds to sites 1 and 2 it blocks transcription from the Pr promoter so there is no more further transcription of cro, if it binds on site 3 will also turn of production of c1 otherwise too much will be made, if it's already won the fight
However, Cro can bind to site 3 and 2 as well reducing production of c1 , and makes more cro tipping the fight in it's favour
You would think Cro would always win fight as it's made first so will reach the sites first, however c1 has a higher affinity for the sites
What wins depends on the level of proteases in cells, as rely on if C11 and C111 work or not
Can then potentially go through induction and then join the lytic pathway
63
What does MreB do?
Protein essential in cell morphology
It's the bacterial cytoskeleton
Coccoid cells don't have MreB suggesting the thesis the default shape for a bacterium
64
What does a logarithmic plot allow you to work out?
Doubling time of bacteria
65
4 growth phases of bacteria?
Lag - adjusting phase
Exponential
Stationary
Death
66
What are anaerobes?
Micro-organisms that preferably grow under low O2 conditions
67
How does temperature affect bacterial growth?
Too cold - transport processes so slow that growth cannot occur
Too hot - protein denaturation, collapse of the cytoplasmic membrane, thermal lysis
Optimum growth rate will occur at cardinal temperature
68
3 things bacteria need for metabolism?
Energy source
Electron source
Carbon source
69
What is a phototroph?
Get energy source from light
70
What is a chemotroph?
Gets energy source from oxidation of organic or inorganic compounds
71
What are lithotrophs?
Get electron source from reduced inorganic molecules
72
What are organotrophs?
Get electron source from organic molecules
73
What are autotrophs?
Get carbon source from CO2, sole or principal biosynthetic carbon source
Generate it yourself
74
What are heterotrophs?
Get carbon source from reduced, preformed organic molecules from other organisms
75
What can E.coli use instead of oxygen as it's electron acceptor in the ETC?
Nitrate
76
What is fermentation?
When an organic compound is both the electron donor and acceptor
Reduced NADH generated in glycolysis
If there is no ETC or terminal electron acceptors , the reduced NADH needs to be oxidised back to NAD+ for glycolysis
Reduced NADH can give pyruvate it's hydrogen creating NAD+ and lactate
NAD+ used in glycolysis to generate more ATP
If other mixed products are produced instead of lactate, process is heterosexual-fermentative
77
Definition of nitrifying bacteria?
Bacteria which are able to grow chemolithotrophically at the expense of reduced inorganic nitrogen compounds
Eg. Nitrsomonas, nitrobacter
78
Differences of bacterial genomes to eukaryotes?
Smaller
Genes densely packed, with no introns
Genes with related function group together (operons)
Coupled transcription and translation
Chromosomes are mainly circular not linear, and only 1 or 2 per cell
Contain plasmids
79
What can happen to plasmids?
Become integrated into the chromosomal DNA forming an episome
80
What are resistant plasmids?
Code for proteins to aid antibiotic resistance
81
2 forms of bacterial DNA replication?
Bi-directional replicated - occurs during cell division and during replication of some plasmids
Rolling circle replication - occurs during replication of some plasmids and during conjugation
82
3 processes involved in horizontal gene transfer?
Transformation
Transduction
Conjugation
83
Describe natural transformation?
Competence:
Extracellular binding
Uptake:
Conversion to single stranded DNA
Stabilisation
Integration:
Homologous recombination
84
Describe transduction?
Generalised:
Donor DNA from any part of the donor can be transferred
Lytic cycle part:
Bacteriophage binds to bacterial cell creating phage DNA in host, creates transducer particle (contains host DNA)
Transduction part:
Transducer particle via a bacteriophage binds and injects DNA homologous recombination creates a transduced cell (can be any of the donor DNA)
Used to transfer antibiotic resistance from one cell to another
Both are bidirectional replication
85
Describe conjugation?
Cell to cell contact
Pilus binds cells together (F+ cell donor, and F-cell recipient)
Transfer of one strand of F plasmid into other cell through pilus, it then is synthesised in the other cells and they separate
Requires DNA synthesis
This is rolling circle replication
Initiated by the nicking enzyme Trap
86
Cells with an integrated F plasmid into their chromosome are called?
Hfr bacteria - can transfer a lot of genes through them
87
Overview of Human-microbial interactions?
Humans are colonised by microorganisms at birth
Most microorganisms are benign - few contribute to health and fewer pose direct threat to health
88
What is normal microbial flora?
Microorganisms usually found associated with human body tissue
Found on skin (sweat glands mainly), respiratory tract, teeth, gut
89
What is a pathogen?
Disease causing microorganism in a susceptible patient
90
What is microbial pathogenicity?
The biochemical mechanisms whereby microorganisms cause disease
91
Do all pathogens have an equal probability if causing infection and disease?
No
92
Infection definition?
A successful persistence or multiplication of a pathogen on or within the host
93
Disease definition?
An interaction which causes significant overt damage to the host
94
Steps of infection and disease?
```
Infection:
Exposure
Adherence
Invasion
Multiplication
```
Disease:
Toxicity or invasiveness (further growth at original and distant sites)
Tissue or systemic damage
95
Low virulence against high virulence?
Basically low risk against high risk
96
Factors that influence the severity of the disease?
Hosts immunological and physiological status
Genetic makeup
Route of infection
Dose- low, high
97
What is LD50?
The infectious dose for 50% of population
98
The decrease or loss of virulence of a pathogen is referred to as?
Attenuation
99
To cause disease disease a pathogen has too?
Colonise host tissue
Grow within host tissue
Avoid host defence mechanisms
Cause damage to the host
100
2 ways pathogen damage the host?
They produce effectors which damage host tissues
They evoke profound immune response which cause damage
101
4 types of toxins?
Neurotoxins - cause paralysis
Enterotoxins - cause sickness and diarrhoea
Cytotoxins - cause cell death
Cytolytic toxins - damage cytoplasmic membrane
102
What are AB toxins?
B portion binds to cell and facilitates translocation of A portion which possesses catalytic activity
103
Toxic proteins that are released from pathogen cells as they grow are called?
Exotoxins
104
Different cell types in immune system?
Innate Immunity:
Non specific general
Immediate response
No immunological memory
Humoral (in blood) examples:
Enzymes
Cytokines
Adaptive Immunity:
Specific to antigen
Lag time from exposure to response
Immunological memory after exposure
105
How do antibodies work?
They recognise foreign pathogens and are said to opsonise them. This aids their uptake by Fc rectors in phagocytes, leading to their eventual destruction
106
What are required for protection against intracellular pathogens?
T cells
T cells bind to infected cells
Perforin makes holes in infected cell's membrane
Infected cell lyses
107
Features of primary response in a vaccination?
The bacteria or virus injected needs to be attenuated (not dangerous), but still needs to be recognisable by immune system
108
What are the advantages and disadvantages of subunit vaccines?
The pathogen can be grown and then use chemicals to break it apart and gather the important antigens
But very specific which can be risky
109
What are the advantages and disadvantages of live attenuated vaccines?
Very broad spectrum so lots of protection
Can have side effects
110
How do you knock out genes to make an attenuated pathogen?
Homologous recombination
111
4 methods for classifying microbial diversity?
Morphological diversity
Metabolic diversity
Ecological diversity
Genetic diversity - looking at ribosomes
112
What's a hyperthermophile?
Microbe that lives in very hot temperatures
113
What's a psychrophile?
Microbe lives in very cold temmperatures
114
What's a halophile?
Microbe that lives in salty conditions
115
What are barophiles?
Microbes that can live in very high pressures
116
Largest group of bacteria known?
Proteobacteria
117
Classification based on 3 domains of life?
```
Domain
Kingdom
Phylum
Class
Order
Family
Genus
Species
```
```
Do
Kids
Prefer
Chocolate
Over
Fresh
Green
Salad
```
118
largest organism in the world?
Honey fungus
119
What do fungi make in manufacturing?
Enzymes
Drugs
Organic acids
Biofuels
120
What organic matter are fungi major decomposers of?
Recycling Carbon and Nitrogen
121
What can fungi do in toxic conditions?
Remove metals and radioisotopes
122
What did Paul Nurse do?
Used fungus to investigate the cell cycle
123
What type of people is fungi disease most dangerous for?
People who have a suppressed immune system
124
Features of fungi?
Eukaryotic
Unicellular growth (yeasts) or filamentous growth (hyphae giving rise to mycelium)
Some are dimorphic so can switch between yeast form and filamentous form
Heterotrophs - an organism which cannot fix carbon from inorganic sources but uses organic carbon for growth
Fungi absorb externally digested nutrients, secrete enzyme through wall, absorb soluble nutrients through wall
Final wall made of Chitin and glucans
Fungal cell membrane - have ergosterol instead of cholesterol
Have haploid nuclei
Produce sexual and aseual spores
125
What are heterothallic fungi?
Require 2 compatible partners to produce sexual spores, whereas homothalic ones ae capable of sexual reproduction by themselves
126
2 way of growing fungi/
Solid state fermentation:
Just lay fungi on trays, still used to make soy sauce
Submerged fermentation:
Grown in chemostats (fermenters), can be batch or continuous culture
127
95% of all fungal enzymes come from?
Aspergillus niger
128
What are viroids?
Only infect plants
Very very small
129
What are mycoplasmas?
Very small
Lack enveloped nucleus
Lack true wall
Look like fried eggs or spirals
Cause plant and animal disease
130
4 species of malaria and features?
```
Plasmodium falciparum:
90% cases in Africa
50% south East Asia
Causes most deaths, main cause of cerebral malaria
Doesn't have a dormant liver stage
```
```
Plasmodium vivax:
90% cases in Asia, South America
50% in south east Asia
Immunity for people with the Duffy Antigen
Can cause severe malaria 1/5 times
Does have a dormant liver stage
```
Plasmodium malariae:
Little bit everywhere
Milder symptoms
No dormant liver stage
Plasmodium ovale:
A bit in Africa
Milder symptoms
Does have a dormant liver stage
131
Features of the plasmodium parasite (malaria causing)?
One end (the apex) of the sporozoite cell contains a complex of organelles specialised for penetrating host cells and tissues
Contain a unique organelle that comprises a type of plastid called a apicoplast
132
Names of lifecycle stages of malaria?
Sporozoites - a motile spore-like stage in the life cycle of some parasitic sporozoans ( e.g. the malaria organism), that is typically the infective agent introduced into a host
Schizonts
Merozites - non motile stage
Trophozoite - the activated, feeding stage in the life cycle
Hypnozoite - sleeping stage
133
What transmits malaria?
Female mosquitos
134
Describe the actual lifecycle of malaria?
Sporozoites are developed in salivary glands from micro or macro gametocytes of female mosquitos and are injected with the salvia
Invade liver cells within 30-60 minutes
In hepatocyte divide asexually leading to schizonts in 6-7 days (some sporozoites enter a dormant phase called hypnozoites in some forms of malaria)
Each schizont gives birth to thousands of merozoites released into the blood from ruptured hepatocytes
Merozoites actively invade Red blood cells
Turns into a trophozoite and injests the cytoplasm
Budding forms more merozoites which burst out and infect more red blood cells
In RBC some parasites enter sexual cycle and differentiate into micro or macro gametocytes which circulate into blood and can infect mosquitos
135
What causes fever in malaria?
Bursting of the red blood cells
Can be used to diagnose which type you have
136
Advantages and disadvantages of living in a red blood cell?
Adv:
Is a rigid cell that supports the stress exerted by blood flow
Dis:
Nutrient poor environment
Short life cycle
They are continuously recycled in the liver/spleen and therefore exposed to the immune system
137
Modifications plasmodium falciparum makes to red blood cells?
Promotes formation of new channels for the import and export of nutrients
Breaks down haemoglobin into amino acids
Places adhesive proteins on the surface of infected RBCS that induce adherence to the endothelium avoiding clearance by host, makes appearance looks nobbly
138
2 types of trypanosome in Africa?
West - Trypanosoma Brucei gambiense - chronic disease
East - Trypanosoma Brucei rhodesiense - acute disease
139
Lifecycle trypanosome Brucie?
Start in mammalian blood
Taken up by tsetse fly during feeding
Development of infective form in salivary glands
Past on during feeding in salvia
140
Disease progression of trypanosome Brucie?
A skin lesion (chancre) may form at the bite site. Then parasite enters the blood
Parasite enters the nervous systems
Fever
Severe sleep disturbances
Coma
Death
141
How does trypanosome Brucie avoid the immune system?
The parasites surface contains variant surface glycoproteins
Survives by changing expression of these genes, so different proteins made, so not recognised by the immune system
Done via Array, telomeric or segmental VSG conversion. Or transcriptional switch
142
Features of Trypanosome cruzi?
South America
Affects diverse range of mammalian hosts
Infective forms develop in the hindgut in the triatomine insect
Infect you because you scratch bite, poo goes into blood
143
Different phases of Trypanosome cruzi?
Acute:
Fever for a few weeks, can infects mucous membranes
Chronic:
Can occur 10 years later as the disease has survived in the cytoplasm of macrophages and muscle cells and neurones
Causes servere cardiacc lesions, or intestinal lesions
144
How to diagnose Trypanosoma?
Staining blood and observing for them via microscopy
For cruzi if it's In chronic stage, can't see in blood so get bitten by new clean bug, then check it's offspring for the disease = Xenodiagnosis
For brucei in late stages have to examine spinal fluid, late stage drugs very toxic can even kill the patient
145
What did T. cruzi most likely Start in?
Bats, as they contain loads of different versions
146
Advantages of living in the intestines?
Nutrients
147
Challenges of living in the intestines?
Transmission
Oxygen
Movement of food
Immune system
148
How is Giardia diagnosed?
Microscope stool
String test
149
What does Entamoeba histolytic cause?
Ameobiasis
Can cause travellers diarrhoea
150
Features of Balantidium coli?
Only known human infectious ciliate
Rare, but more common with people who work with pigs
Fecal-oral route of transmission
Diarrhoea with blood and muscus when symptomatic
151
Features of Blastocystis?
Only known mammalian pathogen within the stremonophiles
May be linked to IBS
152
Features of cryptosporidium?
Often deadly diarrhoea disease of AIDS patients
Found commonly in immune competent people
Have sporozoites stage which attach to epithelial cells using adhesive zone
Indice fusion of microvilli so the parasite becomes encapsulated by host membrane so hidden from the immune system
153
What absorbs atmospheric CO2 in the sea?
Marine protists because they have chlorophyl
Coccolithophores
Diatoms
Dinoflagellates
154
Structure of coccolithophores?
Are part of the group haptophyta
Enclosed by calcareous plates called coccoliths, which are made inside the organism
Each cell contains 2 brown chloroplasts which surround the nucleus
Growth not inhibited by UV light
Turn water turquoise
Produce loads of CaCO3
155
Function of coccoliths?
Protection
Energy production
Added weight so can sink to more nutrient rich areas
156
Features of Diatoms?
Made of silica (glass)
Have 2 different sections
Found in nutrient rich water
157
Features of Dinoflagellates?
Can cause red tides (sea turns red)
Can flouresce bright blue so if eaten their predator will glow in dark so will be easier to be preyed on so they will avoid eating them in first place
Have lifecycle where they replicate in corals, they provide lots of energy for the corals as well
158
What do termites produce a lot of?
Methane
Have microbes in gut which breaks down cellulose overall with Archae produces methane from H2
Similar in cows
159
When can you study protist fossils?
When embedded in Amber (tree sap)
160
What's the Archezoa hypothesis?
Ribosomal RNA sequencing suggesting several early branches protists don't have mitochondria
161
What's a hydrogenosome?
is a membrane-enclosed organelle of some anaerobic ciliates, trichomonads, fungi, and animals.
162
What's an apicoplast?
Organelle
Surrounded by 4 membranes, so formed via secondary endosymbiosis ( protist takes in a protist which has taken in a cyanobacteria eg. containing a mitochondria or chloroplast)
It's essential, so a target in malaria protist
163
What is endosymbiosis?
When a protist took up a cyanobacteria containing an organelle which eventually becomes part of the cell
Key role in mixing up vertical ancestry in tree of life in eukaryotes
164
5 Main supergroups of eukaryotes?
```
Opisthokonta
Amoebozoa
Excavata
Archaeplastida
Sar
```
Unikonts contains Opisthokonta and Amoebozoa
Chromalveolata and Rhizaria are the 2 base groups of SAR
165
Features of Chanoflagellates?
They Opisthokonta
Have flagellum for movement in water
Obtain food by trapping it in their microvilli and engulfing it
166
Features of Microsporidia?
Only live within cells
Cause disease in fish and immunocompromised people
167
Features of Plasmodial slime moulds?
Amoebozoa
Move via mass cytoplasmic streaming
Eats bacteria and yeast
168
Features of cellular slime moulds?
Amoebozoa
Under nutrient starved conditions swarm to form a slug which moves
169
Types of excavata?
Euglena - mixotroph
Kinetoplastids -medically important vector Borne pathogen
All types are normally water borne
170
Types of Archeaplastida?
Made up of plants and algae
171
Features of stramenopiles?
Sar
Have a characteristic flagellum with numerous fine hair like projections
Includes:
Diatoms - glass cell wall
Oomycetes
172
Features of Alveolates?
Sar
Sac bellow their plasma membranes
Includes:
Ciliates
Dinoflagellates
Apicocomplexans
173
Features of Rhizaria?
Sar
Foraminifera - largest single celled organism in deep sea
174
5 types of Firmicutes (Low G + C and gram positive)?
Lactobacillus - Lactic acid producers, human commensal
Streptococcus - many human pathogens and commensals
Staphylococcus - some human pathogens
Bacilus - endospores and some human pathogens
Clostridium - Anaerobes, endspores and human pathogens
175
3 types of actinobacteria (high G + C and gram positive)?
Actinomyces - Filamentous, branching and some human pathogens
Frankia - symbiotic nitrogen fixers
steptomyces - filamentous and produce antibiotics
176
4 types of alpha Proteobacteria (gram negative)?
Agrobacterium - plant pathogen
Bradyrhizobium - symbiotic nitrogen fixer
Nitrobacter - Nitrifying
Rhizobium - symbiotic Nitrogen fixer
177
1 type of beta Proteobacteria (gram negative)?
Neisseria - human pathogen
178
3 types of gamma (Y) Proteobacteria (gram negative)?
Shigella - human pathogen
Escherichia - human commensal, some pathogens
Salmonella - human pathogen
179
1 type of Delta (δ) Proteobacteria (gram negative)?
Bdellovibrio - uses other bacteria as host
180
2 types of epilson (ε) Proteobacteria (gram negative)?
Campylobacter - human pathogen
| Helicobacter - human pathogen
181
Features of pesticides eg. chloroaromatics?
Many percolate through soils, sediments, into ground water and the subsurface, accumulate exceeding inter government limits and are toxic
182
Toxicity within the environment is associated with?
Human health implications including reproductive, teratogenic, mutagenic and carcinogenic effects
183
Exam is referenced
ok
Also show outside reading and innovation
Organism name is underlined
Will be marked down for misspelling
Definitions are key
Must provide named example organisms
