4.2 Energy Flow Flashcards
What does photoautotrophic mean?
They use sunlight as a source of energy
What are all green plants and some bacteria?
Photoautotrophic
What is an essential source of energy for almost all communities?
Light
What are the producers in a few ecosystems?
Chemoautotrophic bacteria
What is chemoautotrophic?
Energy is derived from chemical processes
How is light energy converted into chemical energy?
Via photosynthesis
What is light energy used to do?
Make organic compounds from inorganic sources
What happens to the organic compounds produced?
Heterotrophs eat them to get their chemical energy
How are organic compounds broken down?
Via cell respiration
What happens when organic compounds are broken down?
ATP is produced to fuel metabolic processes
How does energy enter most ecosystem as?
Sunlight
What converts sunlight into chemical energy?
Producers
Where is the chemical energy stored?
In carbon compounds
How is chemical energy transferred to heterotrophs?
Via feeding
What is a trophic level?
The position an organism occupies within a feeding sequence
What position in a feeding sequences do producers always occupy?
The first trophic level
What position are primary consumers and why?
The second trophic level as they feed on producers
What position do further consumers occupy?
Subsequent trophic levels like secondary and tertiary
What is a food chain?
Showing the linear feeding relationships between species in a community
What do arrows represent in food chains?
The transfer of energy and matter as one organism is eaten by another
What direction do arrows point in food chains?
In direction of energy flow
What is the first organism in a food chain?
A producer followed by consumers
What can the energy stored in organic molecules be released to do?
Produce ATP
What is the ATP from organic molecules used to do?
Fuel metabolic reactions needed for growth and homeostasis
What is a by product of metabolic reactions?
Heat
What happens to the heat by product of metabolic reactions?
It is released from the organism
Where is some chemical energy lost to?
- Being excreted as faeces
- Remains unconsumed as uneaten parts of the food
- Respiration
- Released as heat
What are the three ways chemical energy produced by an organism can be converted?
Kinetic energy
Electrical energy
Light energy
When would chemical energy be converted into kinetic energy?
During muscle contraction
When would chemical energy be converted into electrical energy?
During the transmission of nerve impulses
When is chemical energy converted into light energy?
Producing bioluminescence
Why is heat released as a by product?
As living organisms cannot turn this heat into other forms of usable energy
What happens to heat once it is released from the organism?
It is lost from the ecosystem
Why do ecosystems require a continuous influx of energy from an external source?
As heat energy is lost from the ecosystem
Why is the energy transformations process never 100% efficient?
Most of the energy is lost to the organism
How efficient are energy transformations typically?
10%
What does the amount of energy transferred depend on?
How efficiently organisms can capture and use energy?
Why do higher trophic levels have less biomass?
As they store less energy as carbon compounds
What is biomass?
The total mass of a group of organisms consisting of the carbon compounds contained in the cells and tissues
How can scientists measure the amount of energy added to organisms as biomass?
Because carbon compound store energy
What happens to biomass along food chains?
It diminishes with the loss of carbon dioxide, water and waste products to the environment
Why are the number of potential trophic levels are limited?
Because energy and biomass is lost between each level of a food chain
Why do higher trophic levels need to eat larger quantities ?
To obtain sufficient amounts of energy
When will the trophic level become unviable?
If the energy required to hunt food exceeds the energy available from the food eaten
What is a pyramid of energy?
A graphical representation of the amount of energy at each trophic level of a food chain
In what units are pyramid of energy expressed?
Energy per area per timeq
Why will pyramids never appear inverted?
As some of the energy stored in one source is always lost upon transfer
What size should a level in a pyramid of energy be?
one tenth
What will the bottom level of a pyramid of energy always be?
The producers
What do the subsequent levels of a pyramid of energy represent?
Consumers
