MICR221 MIDTERM TEST QUESTIONS WITH ALL ANSWERS VERIFIED
7 views 0 purchase
Module
MICR221
Institution
MICR221
MICR221 MIDTERM TEST QUESTIONS WITH ALL ANSWERS VERIFIED
Extracellular Polysaccharide - Answer-Capsule!
- not every bacteria
-often lost in lab
- ex. slime found in lungs of CF patients (pseudomonas aerginosa) is due to capsule - this is why antibiotics don't really work - can't get through c...
MICR221 MIDTERM TEST QUESTIONS
WITH ALL ANSWERS VERIFIED
Extracellular Polysaccharide - Answer-Capsule!
- not every bacteria
-often lost in lab
- ex. slime found in lungs of CF patients (pseudomonas aerginosa) is due to capsule -
this is why antibiotics don't really work - can't get through capsule
- protects from desiccation (98% water)
- protects from predation
- helps cell adhere to surfaces - but bio fouling is bad!
Capsule gene organization - Answer-Region 1 - (5 genes) - transport across the outer
membrane
Region 2 - (variable) - actual biosynthesis of capsule
Region 3 - (T and M) - transport across cytoplasmic membrane
Pilus genes - Answer-PapA: bulk of pilus fiber
PapE: major component of fibrillum
PapF: needed to couple PapG to pilus fibrillum
PapG: Adhesin!
PapK: connects fibrillum to rest of pilus
PapC: removes proteins from Pap D and forms hole in membrane
PapD: acts as chaperone - directs proteins to Pap C
PapH: anchor
Amphitrichous - Answer-one flagellum at each end of cell
Lophotrichous - Answer-cluster of flagella at one or both ends
Peritrichous - Answer-spread over entire surface of cell
Flagella Hook Associated Proteins - Answer-HAP2: caps filament - critical for assembly
HAP 1 & 3 at junction of filament and hook
Flagella Structure - Answer-Filament: 95% of the flagella
- flagellin gene deficient in cys, trp
- capped by Hap2 - critical for assembly
Hook:
- defined length of 80nm
- HAP 1 & HAP 3 at jungtion of filament and hook
Basal Body
- LPSM rings, LS only in gram +ve
, Flagella Motor Proteins - Answer-MotA and MotB: form proton channel (for energy)
MotB: connects to peptidoglycan layer
Switch proteins : FliN, FliG, FliM
Flagella Basal body rings - Answer-L: in place of outer membrane
P: in plane of peptidoglycan layer
S: above the cytoplasmic membrane
M: in plane of cytoplasmic membrane
- Gram +ve only have L and S rings
- ring proteins have signal peptides
- flagella grows body then hook then filament
Chemotaxis proteins - Answer-CheW: receives chemical signal. Passes on to CheA
CheA: Phosphorylated when repellent present. Transfers P to CheY
CheY: when phosphorylated, binds to switch, rotating flagella
CheZ: dephosphorylates allowing to travel straight
CheR: methylase
CheB: demethylase (methylesterase)
Gram Staining Protocol - Answer-1. Flood slide of heat fixed cells with violet dye for 1
min
2. flood slide with iodine for 1 min
3. wash slide with alcohol 20 sec.
4. Counterstain with safranin red
Gram -ve are stained red.
Gram +ve are stained violet (because colour got stuck in thick peptidoglycan layer)
RED means DEAD for gram +ve because their peptidoglycan layer is degraded
Periplasm - Answer-space between cytoplasmic membrane and outer membrane
Peptidoglycan - Answer-- peptide side chains important for attaching to adjacent chains
via cross links (Nag to Nam)
- important for cell shape maintenance - rigidity
The benefits of buying summaries with Stuvia:
Guaranteed quality through customer reviews
Stuvia customers have reviewed more than 700,000 summaries. This how you know that you are buying the best documents.
Quick and easy check-out
You can quickly pay through credit card for the summaries. There is no membership needed.
Focus on what matters
Your fellow students write the study notes themselves, which is why the documents are always reliable and up-to-date. This ensures you quickly get to the core!
Frequently asked questions
What do I get when I buy this document?
You get a PDF, available immediately after your purchase. The purchased document is accessible anytime, anywhere and indefinitely through your profile.
Satisfaction guarantee: how does it work?
Our satisfaction guarantee ensures that you always find a study document that suits you well. You fill out a form, and our customer service team takes care of the rest.
Who am I buying these notes from?
Stuvia is a marketplace, so you are not buying this document from us, but from seller Perfectscorer. Stuvia facilitates payment to the seller.
Will I be stuck with a subscription?
No, you only buy these notes for £10.51. You're not tied to anything after your purchase.
