Energy transfers in and between organisms- BP Flashcards
What is the source of energy for an ecosystem?
sunlight
what is a consumer?
- animals
- cannot make their own biological molecules
- need to eat plants (primary consumers) or other animals (secondary/tertiary consumers) to obtain biological molecules
decomposers?
- bacteria and fungi
- perform saprobiotic decomposition
- release enzyme onto dead plants/dead animals/animal waste (organic matter) breaking them down to obtain biological molecules
producers?
photosynthetic organisms that manufacture organic substances using light energy, water, carbon dioxide and mineral ions
Why do producers (plants) need biological molecules?
Glucose = respiration, store as starch, make cellulose
Amino Acids = make proteins e.g. enzymes
Fatty Acid & Glycerol = make triglyceride as energy store, make phospholipid for membranes
Why do consumers (animals) need biological molecules?
Glucose = respiration, store as glycogen
Amino Acids = make proteins e.g. enzymes
Fatty Acid & Glycerol = make triglyceride as energy store and insulation/protection, make phospholipid for membranes
Why do decomposers (bacteria/fungi) need biological molecules?
Glucose = respiration
Amino Acids = make proteins e.g. enzymes
Fatty Acid & Glycerol = make phospholipid for membranes
How do organisms carry energy?
Main Source = Glucose
Stored as Starch in plants and Glycogen in animals
Alternative Source = Lipids/Fats/Triglycerides and Proteins
How does energy move through an ecosystem?
by the food chain, begin with producer and then moves onto primary consumer, then secondary consumer, then tertiary consumer – with decomposers occurring at each stage (trophic level)
Why is all the light energy not utilised by plants in photosynthesis?
only 2% is used in photosynthesis – of the rest, a certain part misses the chloroplast, the other parts would be reflected or the wrong wavelength
Why is energy lost along a food chain?
- not all of the organism is eaten
- not all is digested (lost in faeces)
- some lost in excretory materials (eg. urine)
- heat loss to the environment
Effect of energy loss on a food chain?
- places a limit on the length of a food chain
- those at the higher trophic levels (just quaternary consumers) would not obtain enough energy from the food it consumes
What is Productivity?
Amount of Glucose/Energy available to organism
What does a Pyramid of Number represent?
- number of each type of organism at each trophic level
- the numbers decrease as we move up trophic levels due to the loss of energy (not as many individuals can be supported)
- can look inverted when it does not take into account mass (e.g. 1 oak tree or millions of fleas)
What does a Pyramid of Biomass represent?
biomass of each type of organism at each trophic level
biomass = mass of living tissue (based on dry mass, water excluded)
biomass includes biological molecules, organelles, cells, tissues, organs
units for biomass (g per m2 for land based animals, g per m3 for water based animals)
so as we move along a food chain (up trophic levels) there is a loss of energy due to respiration/inedible parts/indigestible parts, so there is less energy to build biomass, so biomass decreases
What does a Pyramid of Energy represent?
amount of energy found at each trophic level
as before, loss of energy occurs along a food chain (respiration, inedible parts, indigestible parts)
What are the units for energy?
kJ/m2 /year
how to calculate efficiency?
(energy available after/energy available before)x100
what measures may farmers take to improve the energy-conversion rate in the animals they rear?
- limiting movement
- heating the environment around the animals
- controlling feed
- remove predators and pests
net productivity equation?
Net Productivity = Gross Productivity – Respiratory [and Faeces] Losses
What is net secondary productivity
amount of glucose stored as glycogen after respiration
What is gross primary productivity?
amount of glucose made by plant in photosynthesis
What is net primary productivity?
amount of glucose stored as starch after respiration
What is gross secondary productivity?
amount of glucose consumed by animal
what is primary productivity?
Amount of Glucose/Energy available in Plants
what is secondary productivity?
Amount of Glucose/Energy available in Animals
what is a natural fertiliser?
- consists of the dead and decaying remains of plants and animals as well as animal wastes
- eg. manure, slurry and bone meal
what is an artificial fertiliser?
mined from rocks and deposits to give an appropriate balance of minerals for a particular crop
how do fertilisers incrase productivity?
- ensure nutrients are readily available to crops
- means the crops are likely to develop earlier, grow taller and have a larger leaf area
- this increasers the rate of photosynthesis
- which in turn increases crop productivity
what are the environmental affects of using nitrogen-containing fertilisers?
- reduced species diversity - favours the growth of some plants, these outcompete other species, the other species die out
- leaching- leads to pollution of watercourses
- eutrophication- caused by leaching of fertiliser onto watercourses
What is leaching?
the process by which nutrients are removed from the soil
What is eutrophication?
the process by which nutrient concentrations increase in bodies of water
