Energy Transfer Flashcards
What is Biomass ?
Dry Mass of carbon or dry mass of tissue per given area
Difference between fresh biomass and dry biomass
Living vs dead
Easy to access vs difficult to access
Variable water content vs small sample size /may not be representative
Unreliable due to varying water content vs unreliable due to unethical to collect large samples
Variable food indigested for fresh mass
How to calculate energy store in Biomass
estimated using calorimetry
Describe the reasons for low efficiency of energy transfer through plants?
- Some of the light energy is reflected.
- Some of the light energy is absorbed by gases or water vapour in the atmosphere
- Some light energy misses the chlorophyll
- Some light energy is the wrong wavelength
Describe the reasons for low energy efficiency from producer to primary consumer and primary consumer to secondary or tertiary consumer?
- Large amount of plants may be in digestible.
- Lost from the animals as the
- Not all part of the plant is eaten eg bark
- Some of the energy is lost in excretion
- Some of the energy is lost in respiration as heat
What is GPP?
Gross primary production =chemical energy store in plants by mass per given area of volume
What is NPP?
Chemical energy store in plant biomass after respiratory losses to the environment
NPP = GPP-R
Equation for net production of customers
N= I- (F+R)
N= Net production of customers
I= Chemical energy store in in digested food
F= Chemical energy loss to faeces and urine
R= Respiratory loss
Suggest how you could determine the dry mass of a sample of plant material
Heat in a oven at high temperatures to evaporate the water
Weigh and heat until no further change in mass as a water content is variable
What is domestic livestock?
Increase productivity by reducing energy losses at each stage so more energy converted to new biomass
Describe how intensive rearing of domestic livestock increases net productivity
- Slaughtered when still growing so more energy transferred to biomass tissue.
- Fed on a controlled diet, a higher proportion of food digested and not lost in faeces
- Movement restricted to so less heat loss from respiration
- Kept warm inside so less heat loss to maintain body temperature
- Genetically selected for higher productivity
State appropriate gross productivity unit
Unit of energy per area per year
Example examples of what animals use nitrogen for in the body
DNA
NAD
NADH
mRNA
TRNA
Amino acids
Proteins
What are the four microorganisms in the nitrogen cycle in order?
- Saprobionts Bacteria converts nitrogen contains compounds into ammonia
- Nitrifying bacteria oxidises ammonia into nitrites then to nitrate by nitrifying bacteria
- Nitrates converts into N2 gas by denitrifying bacteria in anaerobic waterlogged conditions
- Nitrogen fixing bacteria reduces N2 gas into ammonia compounds
Nitrogen cycle
- Plants take up nitrogen from the soil by active transport through the root hair cells and use for amino acids and proteins to grow and reproduce.
- Consumers eat plants and hydrolyse proteins into amino acids and assimilate into new biomass.
- Primary consumers are eaten by secondary consumers and nitrogen passes through the trophic levels.
- Both animals and plants die
- Animals extreme nitrogenous waste.
- Saprobionts bacteria decompose nitrogen containing compounds into ammonia. Nitrifying bacteria oxidises ammonia into nitrites then nitrates. Denitrifying bacteria converts nitrates into nitrogen gas in waterlogged anaerobic conditions to prevent leaching. Nitrogen fixing bacteria reduces nitrogen gas into nitrates in the soil which can be taken up by the plant.
What are phosphates in the body used for?
ATP
Phospholipids
DNA
RNA
Process of phosphorus cycle
- Phospholipids, RNA and and DNA from dead organisms into phosphate ions are decomposed by Saprobionts bacteria .
- Phosphate also found in waste and remains
- Phosphate ions transported by streams, rivers and lakes and form sedimentary rocks
- Weathering and erosion helps phosphate ions dossolve in water and lakes and soils
- Phosphate becomes available for plants to incorporate into biomass
Role of mycorrhizae fungi
Increase absorption of water and mineral ions
Increases total surface area of plant root
How the plant benefits mycorrhizae
The fungus will receive organic molecules such as sucrose and amino acids for respiration
2 types of fertilisers
Natural = manure
Artificial = manufactured, man made pellets containing nitrates, phosphates and potassium ions
Environmental impact of using fertilisers
- Reduced species diversity = plants adapted to soils with high nitrate concentration outcompete other species
- Environmental issues=. Crops are removed therefore less decomposition therefore less nitrates returned to the soil. Fertilisers are used to replace nitrates and phosphorus.
- Leaching = more ins applied to the plant then necessary and so they dissolve in water and washed away which causes eutrophication
Process of eutrophication
- Nitrates washed away into water course and cause build up
- High concentration if ions causes rapid growth of algal bloom
- Algae block sunlight so less light penetrates water so less photosynthesis
- Algae die
- Plants that can’t photosynthesis also die
- Large increase in population of Saprobionts bacteria and thier respiration rate increases
- Bacteria reduce oxygen concentration of water
- Oxygen level depleted resulting in death of other aerobic organisms
- Increase in anaerobic respiration leading to release of toxins = putrid conditions
