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
