Microbes and animals Flashcards
1
Q
Symbiosis
7 points
A
- Obligate - necessary to survival of at least 1 or organisms
Facultative - beneficial but not essential to survival
- Mutualism - both organisms benefit
- Commensalism - 1 benefits, other not affected
- Parasitism - 1 benefits, other harmed
(focus) - Antagonism - 1 harmed other unaffected
- Competition - both harmed
- Neutralism - no interaction
2
Q
Ruminants
5 points
A
- Even toed animals that regurgitate ad chew food after swallowing
- True ruminants - sheep, cattle, goats, antelope, deer, giraffes
- Pseudo-ruminants - camels, llamas
- Herbivores (foraging)
Plants contain high levels of - plant structural polysaccharides - cellulose, hemicellulose -> cant be digested by enzymes in mammalian intestinal tract
3
Q
Ruminants and microbes
4 points
A
- Symbiotic relationship
- Mutualism
- Rumanant provides - environment suitable for microbial growth
- Microbes provide - source of nutrients (from cellulose and hemicellulose) which can be digested by ruminant
4
Q
Microbe needs (to grow & multiply) 6 points
A
- Nutrients
- Aqueous environment
- Suitable temperature
- Suitable PH
- Stable environment
- Waste removal
5
Q
How ruminant provides for microbes needs
6 points
A
Rumen
1. Large sac like organ (comes before stomach in digestive tract)
- Provides region of low flow rate (compared to rest of digestive tract)
- pH 5.5 - 7.0
- 39 C temperature
- Liquid environment
- Food enters rumen first (before any other part of gastro-intestinal tract
6
Q
Importance of pH & temperature
2 points
A
- Microbes have optimal PH and temperature (grow best at)
2. Microbes need to get conditions from surroundings, cant maintain them themselves.
7
Q
Microbes provide ruminant
6 points
A
Nutrients
1. Microbes ferment sugars and polysaccharides including cellulose to provide:
- Microbial waste products - gases & short chain fatty acids (volatile).
- Ruminant absorbs fatty acids - source of carbon & energy
- Protein entering rumen broken down by microbes = amino acids & ammonia
- Amino acids - used to build new microbial cells
- Microbial cells pass into small intestine - digested & amino acids absorbed by ruminant
8
Q
Microbes provide ruminant flow chart
7 points
A
- Protein enters rumen ->
- broke down by microbes ->
- amino acids (& ammonia) ->
- new microbial cells ->
- microbial cells into small intestine ->
- digested ->
- amino acids absorbed by ruminant
9
Q
Compromises - microbes
3 points
A
Anaerobic growth
- Limits types of organisms
- Limits energy production per unit of carbohydrate
- Limits rate of growth, potential to be washed out
10
Q
Compromises - ruminants
4 points
A
- Use VFAs for energy production rather than glucose from starch (less efficent)
- Must synthesise all glucos required (milk, foetus)
- Lower quality protein in microbial cells compared to some components of diet
- Susceptible to metabolic diseases [not most efficent production of energy and low quality protein)
11
Q
Termites & microbes
5 points
A
- Lower Termites only consume wood (which is mainly made of cellulose)
- Cellulose - polymers of glucose
- Termite gut - highly complex microbial community
- Lower termites contain protists, bacteria & archaea to help digest wood
- Obligate symbiotic relationship
12
Q
Corals & microbes
6 points
A
- Reef corals surrounded by calcium carbonate shell
- Mutualistic relationship with bacteria & photosynthetic protists called zooxanthellae
- Zooxanthellae endosymbionts - live within coral cells
- Fix carbon for coral
- Over 90% or coral nutrients obtained from symbionts
- Coral provides nutrients, CO2 & protection
13
Q
Coral bleaching (coral white) 3 points
A
- Zooxanthellae give coral bright colouts
- Coral bleaching occurs when zooxanthellae leaves or loses chlorophyll
- Process linked to global warming - increases in ocean temp = zooxanthellae dying or expelled from coral
