Topic 5 - Ecosystems Flashcards
Light dependent reaction overview
When light is absorbed by chlorophyll it excites electrons.
Oxygen is produced when water molecules are split in the process of photolysis ( not hydrolysis).
The products of the light dependent reaction (and used in light independent reaction) are reduced NADP and ATP.
Describe the structures in a chloroplast that involved in light -dependent reactions of photosynthesis.
These reactions take place in the thylakoids (arranged as stacks - grana) made of membranes and contain chlorophyll and arranged as photosystems/quantasomes.
Pros of glasshouses with artificial lightning vs. Open fields
Crops can be grown all year (inc. out of season).
Plants photosynthesise 24 hours a day.
Less physical damage from weather/animals
Pest control easier.
Control of CO2 temperature, humidity, water supply
Why are higher and lower estimates made for climate change?
Changes in production of gases accounted for:
Higher estimate assumes no change in production of gases
Lower estimate takes into account reduction in carbon emissions.
Explain how increases in CO2 + CH4 released into the atmosphere. May contribute towards estimated changes in mean temperature shown in graph.
CO2 + CH4 both are greenhouse gases
Absorb infra red radiation reflected from the Earth’s surface.
Mean temperature of Earth’s surface increases.
Abiotic vs biotic
Biotic factors involve organisms
Abiotic factors are non-living factors (physical/chemical).
Bacteristatic antibiotic
Prevent reproduction / growth of bacteria
Bactericidal antibiotic
Destroy/kill bacteria
Other animal populations affected
A decrease in (tuatara ) population
Fewer prey eaten by (tuatara)
Prey increase in number
Other carnivores may increase
Because less competition for food from (tuatara)
Predator of (tuatara) might decrease, eat other prey or migrate.
Apparatus for density (different periwinkle species)
Take several readings
Use random quadratic positions
Throw quadrat randomly or generate random number coordinates
The area of quadrat must be known
No. Of individuals in each quadrat is recorded
Mean density : total number of each species and total area sampled.
A pair of green house gases
Carbon dioxide and methane
Carbon dioxide and carbon monoxide
Carbon monoxide and nitrogen
Methane and nitrogen
Carbon dioxide and methane.
Niche of (plant)
The role of an organism (plant) within its ecosystem
(Plant) is a producer
(Plant) provides energy for other organisms - herbivores / primary consumers and decomposes.
(Plant) improves soil eg. holds soil structure together, increase nutrients
A study distribution of (plant) from edge of glacier
Use a transact from front edge of glacier
Sample along the transect using a quadrat (or clumps touching transect )
Select sample sites along transect at set distance - regular, systematic, or flip-flop quadrats (NOT random)
Estimate abundance : calculate number of plants or percentage cover
Use more than one transect ( not repeating investigation)
Record quantitative data e.g. Tally chart, table, graph.
Abiotic factors for plant
Measuring
Soil pH / light - light probe, sensor, meter, data logger
Water - water gauge
Mineral content - dry out soil samples
Reading taken at height of plant
Soil sample around roots
Quadrat
Take several readings getting an average
First gen biofuels - from sugars and vegetable oils from food crops
How do these decrease global warming?
CO2 is a greenhouse gas
CO2 is taken in for photosynthesis (light independent / Carbon fixation ) during production of plants for biofuels.
No net change of carbon dioxide In the atmosphere when biofuels are burnt.
Abiotic factors affecting periwinkle distribution
Light intensity/duration O2 availability in rock pools Temp. pH Toxic chemicals Wave action Height above sea level Length of submersion in water Exposure to air
Biotic factors affecting periwinkle distribution
Predators Availability of food organisms Disease Parasites Competition for food, Competition for space
First stage decomposition cow pat
Putrefaction
Explain how CO2+ NH3 are formed during this stage of decomposition
Microorganisms respire
They undergo aerobic or anaerobic respiration
Which converts organic compounds to CO2 and converts nitrogen compounds to ammonia.
Primary succession
A distance from front edge of glacier increases, the biodiversity/complexity of organisms increases.
Primary succession has occurred.
Algae/lichens are the first organisms to colonise bare rock.
Pioneer species- able to grow in little/no soil -Improve conditions for plants e.g. Change rock into soil, increase humus, increase water content of soil, break up rock fragments to form thin soil, soil structure changes allowing shrubs to grow.
Competition - limiting species present e.g. Never species outcompete previous species.
Decomposition organic matter
Condensation
Estero fixation
Hydrolysis
Polymerisation
Hydrolysis
There is a decrease in mass of leaves during decomposition
Decomposers release enzymes for decomposition.
Formation of monomers that are soluble.
Some soluble molecules soak into the ground and are taken up by organisms
Respiration/ fermentation of glucose by decomposers
CO2 release
Water loss
Worm activity
Animals eat leaves
Pulled into soil
An increase in temp, increase rate decomposition ( up to optimum temp)
Enzymes are used in decomposition increased heat/kinetic energy , increased no. collisions, and energy of collisions between enzymes and substrate and increased ESCs
Increase in temp, increase in rate at which bacteria reproduce
Above a certain temp rate of decomposition would decrease/stop high temperature enzyme become denatured (bacteria killed) (NOT end starts to denature: not a verb, an adjective)
Five piles ash leaves
Rate of decomposition
Purpose?: -
To calculate mean
To give a range of variables for the independent variable
To make investigation valid
To produce reliable data
To give a range of values for the independent variables - the pile of leaves is the independent variable
No mention of mean on table.
Types of plant fibres cows eat
Cellulose fibres
Xylem vessels
Sclerenchyma fibres
Bonds broken in cellulose digestion Ester H Glycosidic Peptide
H
Glycosidic
Beta glucose monomers
Factors affecting decomposition
Increase in temperature.
Decrease in decomposition time.
Decrease in water availability
Decrease in water logging (increases oxygen availability)
Decrease in frozen water
More insects/decomposers in summer
Increases rate of growth of microorganisms
Increases rate of metabolism enzyme reactions
Why cellulose treatment with enzyme before bacteria can use it as an energy source?
Bacteria cannot breakdown cellulose fast enough.
Enzyme/cellulose needed to break down cellulose into beta glucose by hydrolysing 1,4 glycosidic bonds by respiration/fermentation of glucose by bacteria.
2nd gen
Non food biofuel
Cellulose and lignin –bacteria–> ethanol
A part of the plant stem that would contain these polymers, cel lose and login.?
Plant fibres Woody fibres Xylem vessels/tissues Sclerenchyma fibres Lignified tissue
H20 -->light dependent reactions -->O2
|
ATP and ------
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Light independent reactionsReduced NADP
Chloroplast structure
Thalakoid membranes
Arranged as stacks called grana
The stroma is the equivalent of the cytoplasm
Magnification =
Magnification = image length/actual length
Micrometers, uM = ?cm
Micrometers, uM = cm / 1000
Role of RUBISCO in GALP production in the light-independent reaction
RUBISCO is an enzyme/ catalyst In the Calvin cycle *Involved in Carbon fixation: bonding of CO2 to RuBP to form GP. *GP converted to GALP Using ATP and reduced NADP (NADPH) (CO2 to GALP/GP to GALP).
Membranes inside the cytoplasm, are involved in photosynthesis
Compartmentalisation from stroma Site of light-dependent reaction Photosynthetic pigments molecules: chlorophyll Photosystems, electron carrier proteins, within membrane ATPase in thylakoids membranes Photophosphorylation occurs here Provide space for H^+ accumulation For chemiosmosis
10 x 10 cm quadrat
1 square =?%
%cover for species distribution
Each square represents 1%
Count number of squares contains organism
Niche of a plant
The role of a plant within its ecosystem
A producer
Provides energy
Improves soil, e.g. Holds soil structure together, increases nutrients
Provides shelter/habitat for organisms
Woodlice and decomposition and Carbon cycle
Organic compounds/ carbon in plant material
Digestion provides respiratory substrates
CO2 released from respiration
Available for photosynthesis
Woodlice are eaten/decompose
Digestion of cellulose reaction type
Hydrolysis reaction
Chemical nature of cellulose
Polysaccharide
Unbranched
1-4 glycosidic bonds
Why enzyme needed to break down cellulose before bacteria can use it for respiration.
Bacteria cannot break down cellulose fast enough.
Enzyme/cellulose needed to break down into beta glucose by hydrolysing 1, 4 glycosidic bonds.
Then, respiration of glucose by bacteria.
In habitu advantages
Less stress for animals
Animals more likely to breed in martial environment
Animals may require large areas
Problems of releasing large animals back into the wild is avoided e.g. Habituation
Disease is less likely and will not wipe out population.
It allows natural interspecific relationships to exist.
It allows natural intraspecifc relationships to exist.
Family and social structure and behaviour uses large number number of animals needed
Natural diet is available
NPP
Rate energy is incorporated into biomass of organic material
Energy losses in respiration are taken into account (GPP - R) in producers/ plants.
Increase in temp
Increase in NPP
Enzyme effect?
Increase in rate of metabolic reactions
Increase in KE of molecules (substrate and enzyme)
Increase in reaction rate because of more E/S interaction
NPP increases as light increases
Correlation
Increase in light increases rate of photosynthesis
And increases ATP energy available for Calvin Cycle
Light results in excitation of electrons
Temp affects how quickly enzymes work
There is no real correlation between temp and NPP as temperature fluctuates
NPP variation
Variation over short periods of time e.g. More NPP on a sunny day, or in the summer (seasonal)
The whole year gives an average overall
Biomass involved all digestible/inedible organic material.
Rate of productivity of plants may influence how much grazing is possible.
GP losses taken into account for NPP
NPP= GPP - R
Energy is used to provide energy for active transport
Movement - opening of flowers and turning leaves
Glycolysis
NPP is stored energy and is available for the next tropic level
Grazing and NPP
Cattle are primary consumers and eat plants therefore gaining energy available as NPP.
The farmer ensures that there is enough NPP available for his cattle by considering the grazing capacity of the grassland.
Affect on yield of meat/milk: growth rate could change due to a more efficient NPP yielding crop.
Faster Carbon Fixation Benefits
*Carbon fixation produces GP.
*Product is converted to starch.
Faster C-fixation means a faster starch production.
Rate of growth in increased GPP of crop.
Plant Biotic Factors
Competition from other plants Shading by other plants Grazing Trampling Disease
Plant Abiotic Factors
Wavelength of light
Minerals
CO2 concentration
pH of solution
Benefits of plant decay products
Decomposition by microorganisms which respire and release CO2 which can be used again in photosynthesis
Methane is released (in anaerobic conditions) and is available as fuel.
How quadrat works: caluclating species density, number per square unit
Several readings
Use of random quadrat positions
Dive random positions (using random no. generator, or throw randomly)
Known area of quadrat is used
No. of individuals in each quadrat are counted and recorded
Mean density is calculates using total count e.g. total no. of each species / total area sampled
species density, number per square unit
Global Warming: The Greenhouse Gas Effect
Greenhouse production occurs
They build up in the upper atmosphere
CO2 + CH4 are greenhouse gases
which absorb IR
reflected from the Earth’s surface
They prevent IR escaping
Temperatures maintained are higher than they would otherwise be
Increased levels of greenhouse gases increases the greenhouse gas effect
Mean temp. of the Earth’s surface is increasing.
Climate Change Evidence
Dendrochronology
Peat-bog pollen analysis
Temperature Records
Estimates of CO2 levels in air
Why does a decrease in fossil fuel use not necessarily equate to a decrease in global warming?
CO2 is produced by using fossil fuels.
No direct evidence that CO2 leads to global warming.
Scientists may be biased: employed by company or country with vested interest
CO2 is released from other processes
e.g.Removal of C sinks leads to increase in CO2
Other greenhouse gases: CFC, H2O vapour, CH4
Ruminant animals, paddy fields, melting ice,
Natural cycles involved: solar, volcanic
Past evidence used - not an indicator of future events - limitations of models of climatic events
Decomposition
Microoragnisms/fungi involved Respiration of mircorganisms cccurs Aerobic/ anaerobic respiration occurs Coverts organic compoiunds to CO2 Converts nitrogen compounds (proteins/amino acids) to ammonia
Speciation
(Birds on mainland could live in all regions so there is no restriction of gene flow. But are separate from birds on islands)
Geographical isolation occurs e.g. a physical barrier/allopatric speciation
There are different selection pressures between e.g food sources, different habitats
Mutations occur
This results in adaptations to conditions
These alleles/genes are passed on to offspring
Resulting in gene pool change
Increase in frequency of these alleles
Reproductive isolation occurs
