Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Microbiology > lectures 19-21 > Flashcards

lectures 19-21 Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

proteins in microtubules

A

alpha and beta tubulin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

3 divisions of eukaryotic organisms

A

animal parabasilids
plant-protists
diplomonads

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

what are microtubulins involved with

A

Cell shape
Chromosome movement in cell division
Cell motility (cilia and flagella)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

energy source of flagella in bacteria

A

proton pump in membrane

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

energy source of flagella in protists

A

ATPase dyenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

microfilaments

A

~7nm in diameter
Polymers of actin
Involved in maintaining and changing cell shape

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

hydrogenosome

A

Lack cristae and the TCA cycle
Present in anaerobic protists
Metabolism is fermentative
Oxidation of pyruvate

membrane enclosed organelle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

pinocytosis

A

the uptake of nutrients present in solution

characteristic of protists without a differentiated oral cavity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

phagocytosis

A

requires special organelles (e.g. cytostome, oral funnel, pharyngeal basket, etc.)
three steps: food capture, phagosome formation, and digestion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

contractile vacuole

A

contraction of vacuole expels water from cell

vacuole becomes full as canals take up water from cytoplasm and move it to vacuole

ciliates are hypotonic

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

protist ‘eyespot’

A

photoreceptive organelle which through photoreceptor proteins causes flagellar to move through signal transduction.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

do all protists have mitochondria

A

no

energy is generated through alternative routes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

diarrhoea symptoms

A

A loose or watery stool at least three times a day,.

Results in fluid loss and dehydration

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

diarrhoea causes

A

viruses/bacteria/protists

rotavirus

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

3 types of diarrhoea

A

osmotic

  • impaired absorption
  • excessive solutes
  • enhanced excretion
  • enterocyte malfunction

inflammatory

  • mucosal invasion
  • leukocytes in stool

secretory

  • toxin associated
  • excessively watery
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

solutions to high child mortality rates from diarrhoea

A

Delivery of life-saving treatment of low-
osmolarity oral rehydration salts (ORS)
and zinc tablets.

Vaccination.

Provision of safe drinking water and sanitation.

Improved hygiene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

zinc deficiency

A

reduces the number of B and T lymphocytes (CD4+ lymphocytes in particular) through increased apoptosis, and reduces their functional capacity

disrupts the intestinal mucosa

reduces brush border enzymes

increases mucosal permeability and the intestinal secretion of water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

importance of zinc

A

stabilises cell membrane

acts as a potassium channel blocker, inhibiting cyclic adenosine monophosphate-mediated chlorine

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

faecal-oral transmission

A

when bacteria or viruses found in the stool of one child (or animal) are swallowed by another child

20
Q

encystment

A

helps the microbe to disperse easily, from one host to another or to a more favourable environment

21
Q

excystation

A

cyst wall breaks down when the encysted microbe reaches an environment favourable to its growth and survival

22
Q

microbial cyst

A

a state of suspended animation in which the metabolic processes of the cell are slowed down and the cell ceases all activities like feeding and locomotion

excreted in faeces
infectious
resistant

23
Q

trophozoite

A

a growing stage, where nutrients are absorbed from the host

inhabits intestinal tract
not infectious
motile

becomes a cyst

24
Q

dysentry

A

infection of large intestine

blood and mucous in stool

25
Q

gastrointestinal tract infections

A

nausea, vomiting, diarrhoea, abdominal distress

26
Q

gastroenteritis

A

disease of small intestine and indicates excessive secretion relative to absorption.

Results in fluid and electrolyte loss

27
Q

layers of gi tract

A 
mucosa
submucosa
muscle
serosa
lumen
28
Q

functions/features of intestinal structure

A

Large surface area: 200x skin.

Protect rest of body from intestinal content.

Take up nutrients from food.

29
Q

effect of parasite damage to gi tract

A

Water absorption impaired due to epithelial damage.

Crypt cells produce new cells but excrete water and Cl-.

Water not reabsorbed with Na+

30
Q

amoebiasis

A

3rd leading cause of parasitic death

31
Q

where do trophozoites replicate

A

large intestine

32
Q

entamoeba histolytica

A

anaerobic parasite
causes amoebiasis

lyses cells in contact dependent manner
eats its way into epithelium

33
Q

how do entamoeba histolytica get access to circulatory system

A

erode mucous layer
break down extracellular matrix
kill neutrophils
Perforation of serous layers leading to peritonitis (inflammation of peritoneum)

34
Q

virulence factors of entamoeba

A
  1. Adhesion – Gal/GalNAc lectin
  2. Mucous breakdown – Cysteine proteases
  3. Cytotoxicity – Pore forming peptides (Amebapore)
35
Q

giardia

A

Most common parasite isolated from human stool.

Colonises upper portions of the small intestine

Often results in asymptomatic infections

rarely penetrates cell wall

produces resistant cysts

36
Q

giardia adhesive disk

A

Important for adhesion to intestinal epithelium.

Made from cytoskeleton and contractile proteins.

Unique cytoskeletal element called a microribbon

37
Q

symptoms of acute giardisis

A 
diarrhoea
bloating
nausea
weight loss
malaise
flatulence
38
Q

giardia pathogenesis

A

Attachment could cause irritation and mucosal injury.

Villus blunting, enterocyte apoptosis.

Increased crypt cell activity: hyperplasia with hypersecretion of Cl- and water.

39
Q

treatment of giardisis

A

nitroimidazole

e.g. metronidazole

40
Q

balantidium coli

A

infectious ciliate.

Rare: <1% - common in people that work with pigs.

Fecal-oral route of transmission.

When symptomatic: diarrhoea or dysentery.
(if invades intestinal epithelium shows diarrhoea similar to Entamoeba dysentery with blood and mucus)

Nuclear dimorphism
Asymmetric division

41
Q

blastocystis

A

Only known mammalian pathogen within the stramenopiles

linked to irritable bowel syndrome

42
Q

cryptosporidium

A

apicomplexan parasite

diarrhoea

43
Q

extracytoplasic association - crytosporidium

A

Sporozoites do not invade enterocytes but attach to epithelial cells.
Induce fusion of microvilli: parasite encapsulated by host membrane.
Hidden from immune system

44
Q

sexual reproduction - cryptosporidium

A

Two rounds of asexual reproduction of zygote to generate oocyst
Thick-walled ones thought to be excreted and thin-walled cysts reinfect.
Healthy individuals suppress merozoite release.

45
Q

transmission cycles- crytposporidium

A

Although typical fecal-oral route,
Cryptosporidium notorious for waterborne outbreaks.
Drinking water problems from surface water reservoirs.
Oocysts resistant to routine chlorine treatment.
Zoonotic C. parvum from animal waste. Up to 100 billion oocysts excreted by calves

Microbiology (6 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions