01 - 03 - Introduction to Microbiology & Immunology and Bacterial Structure Flashcards
The Gram stain highlights the outer membrane present in…
Gram negative bacteria
Gram stain method (4)…
- Heat fixing (crystal violet turns cells purple)
- Iodine (1 min)
- Decolourising (alcohol, 20s)
- Counterstain (safranin, 1-2 mins)
When decolourising with alcohol (stage 3 of Gram staining), gram negative bacteria will…
Decolourise
The safranin counterstain will turn ( gram negative / gram positive ) bacteria ( colour ) …
Gram negative, pink
Electron microscopy provides higher resolution images than a light microscope, but it requires…
Dead / fixed cells in a thin cross-section
Cryoelectorn microscopy + tomography uses samples flash frozen from their ‘live’ state. There is no need for…
Fixation, embedding or sectioning
Fluorescent microscopy and digital imaging uses either (2)…
Immunofluorescence or Green Fluorescent Protein (GFP)
Immunofluorescence can be either…
Direct (fluorescent antibody binds protein of interest) or indirect (secondary fluorescent antibodies bind primary antibody, which binds to protein of interest)
GFP comes from a jelly fish gene. Adding it to the gene sequence results in a protein that…
Glows green
Immunofluoresence can be used to detect…
Specific proteins
Immunofluoresence requires…
Dead / fixed cells
FtsZ is analogous to which eukaryotic protein?
Tubulin (microtubules)
MreB fillaments form a…
Spiral structure along the length of the bacteria
MreB fillaments are analogous to which eukaryotic filament?
Actin
Crescentin is a protein which gives some bacteria their…
Curved shape
MinD is a protein which…
Oscillates between the two poles of the cell in order to establish the centre to position cell division machinery
Gram positive bacteria cell walls contain…
Teichoic acid
Beta lactams target…
Bacterial cell walls
Gram negative bacteria have an extra lipopolysaccaride layer which can be…
Shed to evade the immune system
It regrows, but with a different configuration which will not be recognised
Lab strains of bacteria lack this protective protein layer…
Proteinaceous S-layer
The proteinaceous S-layer is a…
Crystilline protein lattice which is protective and selective
Bacterial capsules are made from…
Polysaccharide
Bacterial capsules are ( always / sometimes / never ) covalently attached…
Sometimes
Pili an fimbriae can be involved in (4)…
- Conjugation
- Attachment / adhesion
- Pathogenesis
- ‘twitching’ motility
The flagella results in movement known as a…
Random biased walk
Chemotaxis is…
The ability of the bacteria to adjust the length of movement in a direction based on whether it is moving up or down a concentration gradient
Endospores may be triggered by…
Starvation
Sigma F factor is present in the…
Mother cell
Sigma E factor is present in the…
Pre-spore
Biofilms are communities of bacteria held together by…
A polysaccharide matrix
Examples of biofilms are (2)…
- Dental plaque
* Biofilms which cause complications in catheters
Psychrophiles are bacteria able to survive in extreme…
Cold
Hperthermophiles are bacteria able to survive in extreme…
Heat
Halophiles are bacteria able to survive in extreme…
Salinity
Barophiles are bacteria able to survive in extreme…
Pressures
Bacteria able to withstand high and low pH are known as…
Alkaliphiles and acidophiles respectively
Some bacteria are able to generate their own food, even in the absence of light from CO2 and SO2 in a process known as…
Chemosynthesis
Microbiota
Microorganisms that live in/on/around (us)
Microbiome
The genome of the microbiota
