Energy Transfers Flashcards
(25 cards)
What is a saprobiont?
Extracellular secretion of enzymes break down dead matter
How do plants get chemical energy?
Photosynthesis:
Light energy + inorganic molecules (H2O + CO2) -> chemical energy + organic molecules (glucose)
What is the energy transfer equation?
Energy transfer = energy available after the transfer / energy available before the transfer x 100
Why is energy transfer so inefficient?
Not all digested
Using for movement
Not entire organism eaten
Excretion
Respiration
Heat loss (homeostasis)
Not all light hits chloroplasts
Wrong wavelength - most light reflected
What is biomass?
The dry mass of tissue
Represents chemical energy store
What forms the biomass?
Sugar synthesised by plant and used as a respiratory substrate
Rest are used to make other groups of biological molecules
What is the relationship between gross primary productivity and net primary productivity?
NPP = GPP - R
What is Gross primary productivity?
Chemical energy store in plants biomass, in a given area or volume
What is Net primary productivity?
Chemical energy store in plants biomass biomass after respiratory losses to the environment have been taken into account
How is chemical energy store is dry biomass estimated?
Using calorimetry
What is NPP for?
Plant growth and reproduction
Available to other trophic levels in ecosystem, such as herbivores and decomposers
What is the equation for net production of consumers?
N = I - (F + R)
I = chemical energy store of ingested food
F = energy lost in faeces and urine
R = energy lost in respiration
What is the most production ecosystem?
algal beds + coral reefs / tropical forest
as high temps, high water, high light - intensity + duration
What is calorimetry?
measures heat release
chemical energy store
What is GM / selective breeding?
Individuals with desired traits such as fast growth rate, high meat/milk production
How does GM / selective breeding increase efficiency?
shorter growing periods reach market readiness with fast turnover in production cycles
increases profitability
What are the issues in GM / selective breeding?
Expensive
decreases genetic diversity
less adaptable to changing conditions
What do farmers do in intensive farming?
feed animals specialist, high protein food
confined spaces
dark (reduce movement)
controlled temperatures
How does intensive farming increase efficiency?
low energy needed
less death by diseases
decreased respiration
What are the issues with intensive farming?
significant ethical concerns
nutrition concern -> affect taste + nutritional value
hidden ethical + health concerns
What do farmers do in simplify food webs?
monoculture: single plant species cultivates in large area -> other species removed (pesticides)
How does simplify food webs increase efficiency?
GPP of crop increases as more energy from sunlight converted into biomass by species therefore they get all resources
Increased NPP as fewer organisms consuming crops so a lower loss of edible biomass
What are the issues with simplify food webs?
monocultures can decrease number of pollinators in an area as lack of plant diversity
Pesticides can harm non-target species -> disrupting ecosystem balance
How can you determine the dry mass of a species?
heat at 100°C to evaporate water
weigh and heat until no further change in mass
