13.2: Energy transfer and productivity Flashcards
Organic compounds
Chemical compounds in which 1 or more carbon atoms are covalently linked to atoms of other elements
usually H,O or N
Where do plants synthesis organic compounds from?
The atmosphere or aquatically
Respiratory substrate
A molecule from which energy can be released to produce ATP
eg: glucose, proteins, lipids, carbohydrates
Most of the sugars synthesised by plants are
respiratory substrates
Energy source for ecosystems
sunlight
Gross primary production
GPP
The total quantity of the chemical energy store in plant biomass in a given area/volume in a given time
Net primary production
NPP
The energy left over after some of GPP is used in respiration
Respiratory losses
R
The energy lost from GPP through respiration
Consumer production equation
N = I - (F+R)
Why do most food chains have 4-5 trophic levels
Energy transfer between the trophic levels is low so there is insufficient energy to support more
Biomass quantity up the trophic levels…
decreases
Key elements of factory farming
restricted movement
environment is kept warm
feeding controlled
predators excluded
Pesticides
Chemicals that kill pests
DDT pesticide
persistent pesticide which can help fight the spread of malaria but overuse can lead to bio accumulation which harms organisms at the top of the food chain
Why is widespread use of insecticides regulated
may cause many problems
