C4.2 Flashcards
Transfers of Energy and Matter
Food Webs
What is an Ecosystem?
- Refers to both biotic communities and the abiotic factors in an area.
How does energy move throughout an ecosystem?
- sunlight,
- heat
- gasses like CO2, heat and compounds like glucose and ATP.
Food Webs
What does the First Law of Thermodynamics say?
(Law of Conservation)
“Energy can be neither created nor destroyed”
- It can change forms but the amount remains constant.
- Energy consumed originated as solar energy absorbed by plants. It further changes from chemical energy to crating ATP and kinetic energy (for movement) and some is converted to heat and released.
Food Webs
What does the Second Law of Thermodynamics say?
“When energy transfers forms it often is transofrmed into a less usuable form”.
(entropy or disorganisation of a system increases when energy is transformed –> meaning that –> less usable heat energy is generated when energy changes forms)
Food Webs
What is the role of a PRODUCER in an ecosystem?
All energy needed for the maintaining of life can be traced back to the input of sun into an ecosystem.
- Every cell needs ATP to function –> ATP is produced by converting organic carbon compounds (carbohydrates, fats, and proteins).
- The carbon compounds all come from carbs made from plants, algae and some bacteria in the process of photosynthesis. –> they are able to use solar energy to break the bonds in H2O and CO2 and convert them into sugars. —> sugars are turned into ATP in their own cells and are eaten by consumers who are then eaten by more consumers.
- Producers create the carbohydrates that fuel the entire ecosystems, and thus are photosynthetic (or sometimes chemosynthetic) organisms.
Food Webs
What is the role of a CONSUMER in an ecosystem?
- They obtain energy from the carbon compounds on which they feed.
- they are a subset of heterotrophs, and they specifically notable in discussing ebergy interactions since they directly transfer energy in ecosystems. –> as they kill and ingest living organisms.
Food Webs
What is the role of DECOMPOSERS
- Decomposers help to remove the exoskeletons/ bones and plant matter that is left behind in the environment, alongside feces from animals.
- They release enzymes and can break down and use those unconsumed parts –> providing energy for them also retunring compounts, RECYLING NUTRIENTS, to the soil to help future plants grow.
- They prevent the build up of unused matter which would waste habitat space.
Food Webs
What do we mean by a Trophic Level?
- Trophic level –> as a feeding role in the ecosystem.
- The official definition –> indicates how many organisms in an ecosytem energy has flower through.
- Plants are the first trophic level as they represent the first transfer of solar energy into chemical energy.
- A consumer who then eats the plants –> second trophic level –> as it is the second energy transfer.
Food Webs
What is Assimilation?
- We do not only require glucose, we also need other molecules to build proteins for msucle and tissues and create fat for our cell membrances.
- The process of digesting food contiaining carbon based compounds and then using the component s of it to build new things for the body –> ASSIMILATION.
(post-digestion use of the nutrients)
Food Webs
Different between an open and closed ecosystem.
In both —> energy has the potential to enter (as solar energy) and leave (as heat into the atmosphere)
OPEN: new matter can enter and leave, like water entering and leaving, and species migrating. Ecosystems are typically open.
CLOSED: matter can not enter or leave, only be recyled. EG: a terrarium.
Food Webs
Difference between primary, secondary and tertiary consumer.
PRIMARY: eats a producer
SECONDARY: eats a pimary consumer
TERTIARY: eats a secondary consumer.
- However, many animals have more than one food source, thus can be different types of consumer at differernt types. (track the origin of all its food on a food web.)
Food Webs
Difference between a food chain and a food web.
NOTE: Arrows represent the direction of flow of energy.
FOOD CHAIN: Following a producer through a linear set of consumers.
FOOD WEB: Interlinking food chains, more accurate, shows how most organisms have more than one predator and more than one avilable prey.
Food Webs
Difference between photoautotrophs and chemoautotrophs.
Autortrophs synthesize their organic molecules from inorganic substances.
PHOTOAUTOTROPHS: take light energy from the sun and combine it with substances (H20 AND CO2) to make glucose through photosynthesis.
CHEMOAUTOTROPHS: also take CO2 but instead of sunlight –> they use other inorganic compounds such as iron or sulphur as the energy source to fix carbon dioxide into glucose. –> can also oxidize chemicals and use the energy from those (exothermic) reactions to synthesise glucose. (EG: bacteria and archae)
Food Webs
Primary Prodction.
“The accumultation of carbon compounds in biomass by autrotrophs.” –> essentioally measures how much photosynthesis is done in an ecosystem.
Gross Primary Production: all biomass of carbon compounds made by plants in photosynthesis.
Net Primary Production: Considers that a lot of the carbon compounds made by plants are used themselves in cell respiration and their life processes –> the net is stored as plant matter made avilable to consumers.
Energy Pyramids
What is meant by the term Secondary Production?
“The accumulation of carbon compounds in biomass by heterotrophs.”
Gross secondary production: amount of carbon compounds consumed by primary consumers but then they would use much of that energy for themsleves. (in celluar respiration and much lost as heat in the process.)
Leftover energy: is then stored on organsism as growth -> made available to the next consumer level, which is the next secondary production.
SECONDARY PRODUCTIVITY DECREASES WITH EACH TROPHIC LEVEL.
Energy Pyramids
Energy loss between trophic levels.
Three main reasons for the loss between levels:
1) Incomplete Consumption
- only parts of the plant are eaten, bones of animals often discarded.
2) Incomplete Digestion
- not all parts are digested/absorbed, others pass through as faeces.
3) Cell respiration
- a lot of the carbs consumed are broken apart to form ATP and released as gaseous carbon dioxide to the environment. Heat is also lost during cell respiration.
