Wainwright (Spring) Flashcards

1
Q

Without MOs there’d be no life on Earth, why?

A
  • maintain atmospheric mix (prod and consume N, O etc. by feedback)
  • maintain soil fertility
  • remove wastes, inc sewage
  • break down leaf litter and wastes (mainly fungi)
  • cycle elements, essential for plant growth
    • -> bacteria cycle N, P and S
    • -> fungi cycle C
  • marine algae main CO2 adsorbers, phytoplankton decrease man made CO2 in oceans
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What do all organisms req for growth?

A
  • source of energy

- C for building biomass

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

What is heterotrophy and the 2 types?

A
  • energy obtained by breaking down preformed C via resp
  • aerobic (more efficient), C –> CO2 + H20 + heat
  • anaerobic, C –> CH4 ( C also goes to form biomass)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is autotrophy and the 2 types?

A
  • gain energy by performing chem reactions
  • C obtained by fixing CO2
  • chemoautotrophy (bacteria), NH4+ –> NO2- –> NO3-
  • photoautoptrophy (ps), in higher plants and algae
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Purpose of nitrogen cycle

A
  • N req by all living organisms to make protein
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

In what form do plants take up N?

A
  • nitrate or NH4
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Steps of nitrogen cycle

A
  • ammonification/ N-minerilisation
  • nitrification
  • denitrification
  • N fixation
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Ammonification/ N-minerilisation

A
  • 1st step
  • converts organic N to NH4+
  • done by most aerobic and anaerobic bacteria, so occurs under most env conditions, eg. waterlogged soils
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Nitrification

A
  • eg. of chemoautotrophy
  • bacteria Nitrosomonas ox NH4+ to NO2- and gains energy, while fixing atmospheric CO2
  • Nitrobacter ox NO2- to NO3- and gain energy while fixing CO2
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Denitrification

A
  • under anaerobic conditions (soil waterlogging), NO3- red to N2(g) (= dinitrogen)
  • large no. heterotrophic bacteria do this
  • NO3- lost to farm land (negative process)
  • sewage operatives use to convert urea to safe waste gas
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

N fixation

A
  • symbiotic process between certain plants and Rhizobium
  • common in legumes or asymbiotic plants
  • bacteria (eg. azotobacter) live as “free living” N-fixers and not in direct symbiotic assoc w/plants
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Where does symbiotic N-fixation occur?

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

“Infection” process

A
  • Rhizobium attracted to plant root
  • infection occurs through crack in root
  • Rhizobium multiplies greatly and prod bacteroid
  • plant lays down nodule around bacteroid
  • plant donates C (sugars) to Rhizobium, which donates N by fixing atmospheric N2
  • this is mutualistic symbiosis
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

How is Rhizobium attracted to plant?

A
  • each plant prod own specific attractant for specific Rhizobium
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is sewage treatment needed?

A
  • increasing pop, mainly Victorian London
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Main aim of sewage treatment

A
  • removes organic faeces and urine
  • removes pathogens from drinking water
  • remove solid C wastes
  • remove N waste, urea leads to NO2- prod, toxic to newborns and NO3- prod, can cause stomach cancers
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

How did sewage systems evolve during industrial revolution?

A
  • civil engineers, eg. Bazalgette, did lots to intro sewage systems in London etc.
  • simple improvements made big difference, eg. egg shaped sewers to allow rapid flow at bottom
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Where is sewage a major problem?

A
  • urban centres w/ large pops
  • industrial areas which prod heavy metals and pollutants
  • intense agriculture, eg. large scale beef prod on feedlots
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

How can human and animal waste spread disease?

A
  • bacteria cause cholera, food poisoning etc.

- viruses cause polio

20
Q

Types of sewage system

A
  • septic tank
  • filter bed/contact bed
  • activated sludge process
21
Q

Septic tank

A
  • simplest system
  • aerobes at top of tank and anaerobes at bottom
  • water passed into soil into distribution field
  • MOs in soil finish purification
  • distribution field must be away from water supply
22
Q

FIlter bed/contact bed

A
  • bed made of coke/limestone, covered w/ biofilm

- works in same way as septic tank

23
Q

Activated sludge process

A
  • most efficient
  • aerobes at top of tank and anaerobes at bottom
  • solid waste moved to anaerobic digester
  • CH4 given off made into energy or sold
  • some of material taken back to beginning to stop dilution of organisms
24
Q

Testing drinking water for waste

A
  • BOD (biochem O demand)
  • full (no air bubbles), use O2 probe to measure amount, leave in dark for 3 days and measure again (so no ps), if MOs then O2 levels decrease as use O2
25
Testing drinking water for pathogens
- membrane coliform count (want it to be low) - measure non pathogenic E. Coli (indicator organism) - usually incubated at 37ºC, or 44ºC for faecal coliforms
26
What is MRSA?
- methicillin resistant staphylococcus aureus
27
Methicillin
- broad spectrum antibiotic | - resistant bacteria usually resistant to other penicillins
28
Last resort antibiotic
- vancomycin | - resistance to this also developing
29
MRSA big killer
- kills more is US and Europe than AIDS | - causes 1/2 soft tissue and skin infections in intensive care
30
Indolent infections
- slow to heal, esp in those w/ type II diabetes
31
Why are alternatives to antibiotics req?
- take time and money to develop | - little profit, so less incentive and req govt input
32
Biotherapy
- using live organisms on body | - distinct from use of chemicals prod by MOs
33
Maggot therapy
- treat long standing indolent antibiotic resistance wounds - use green blowfly, not blue - modern version dev by Baer = Debridement therapy - maggots eat rotting flesh, won't eat bone and prod own antibiotics that aid healing
34
Honey therapy
- used on external indolent wounds, eg. mastectomy - many bacterial pathogens sensitive to antibac properties of manuka honey - works by: --> osmotic effect (low water activity as most water molecules assoc w/ constituent monosaccharides) --> H2O2 (released by slow ox of glucose, acts as antiseptic --> pH (too acidic for most bacteria to grow --> non-peroxide antibiotic activity
35
Mycotherapy
- use of living mycelium of antibiotic prod fungus on wound - prod penicillin, patulin and complex chemicals - 'homemade penicillin'
36
Danger of fungal infections
- major killer in AIDS patients, as immunocompromised
37
In what form can fungal infections survive?
- saprophytes
38
Where do fungal infections affect?
- affects skin and mucus membranes, as like damp | - eg. throat, vagina, anus
39
Dermatophytases
- skin infections by filamentous fungi - eg. ringworm - breakdown skins keratin by prod keratinases - can be caught from soil or animals, =keratinophilic
40
Predisposition
- genetically susceptible to infections
41
Mucosal yeast
- eg. thrush - looks like large bacteria - reprod by budding - often latrogenic infections (= passed on by doctors) - dimorphic
42
Systemic mycoses
- eg. Farmers lung, airborne spores grow inside lung, mimics TB - can infect organs, eg. lungs, heart, liver - can be fatal
43
Mycetoma
- eg. Madura foot, grows in lymph system and blocks it, liquid build up - common cause of limb loss in dev countries
44
Fungi infections in AIDS
- P. carinii thought to be protozoa, found to have life cycle on lungs - thrush main killer, final infection - now antifungal antibiotics, but no antifungal immunisation vaccines
45
Antifungal antibiotics
- griseofulvin, dermatophyte skin infections - nystatin, thrush infections by peccary/douche - amphotericin B, systemic fungal infections - fluconazole, thrush infections, taken orally