5- Photosythesis, Respiration And energy Transfer, Nutrient Cycles Flashcards
1
Q
What does the lower epidermis do
A
Protects plants form water loss infection and injury
2
Q
What is the photosynthesis equation (symbol)
A
6H2O + 6CO2 —> C6H12O6. + 6O2
3
Q
In photosynthesis, light energy is first changed into ….
Energy and then into …… energy
A
Bond
Chemical
4
Q
What are the 3 main stages of photosynthesis
A
Capturing light energy by photosynthetic pigments
Light dependent reaction
Light independent reaction
5
Q
What are the products of the light dependent reaction
A
Reduced NAPD
ATP
o2
6
Q
What are the 2 district regions in a chloroplast
A
Grana
Stroma
7
Q
Describe the grana
A
Stacks up to 100 disc like structures called thylakoids
Some thylakoids have tubular extensions wich join up thylakoids to adjacent grana (called lamella)
8
Q
Where is chlorophyll
A
In the thylakoids
9
Q
Describe the stroma
A
Fluid filled matrix
Contains starch grains
10
Q
What are the 2 raw materials of photosynthesis
A
H2O
Co2
11
Q
Where does the light dependent reaction occur
A
Thylakoids membrane
12
Q
Where does the light independent reaction occcur
A
Stroma
13
Q
What are the products of the light independent reaction
A
Glucose
14
Q
The light dependent reaction s involves the capture of Light, the energy is used for what 2 purposes
A
Add an inorganic phosphate to ADP making atp
Photolysis - H+ ions and OH - ions made when water is split by light
15
Q
Oxidation results in energy …..
A
Given out
16
Q
Reduction results in energy …
A
Being taken in
17
Q
Describe the making of ATP in the light dependent rweaction
A
When a chlorophyll molecule absorbs light energy, it excites a pair of electrons within thus chlorophyll molecule.
They leave the chlorophyll molecule
The electrons that leave are taken up by an electron carrier, having lost a pair of e- they have been oxidised
The elctron carrier has been reduced
The electrons are now passed along a number of electron carriers in a series of oxidation and reduction reactions
These electron carriers form a transfer chain that is located in the thylakoids memebran e
Each new carrier is at a slightly lower energy level than the previous one so the electrons lose energy at each stage
Thus energy is used to combine and inorganic phosphate molecule with an ADP to make atp
18
Q
What is photosytemt 2 called
A
Photosytem p680
19
Q
Describe photolysis
A
The loss of electron that happen when light strikes the chlorophyll molecule leave it short of electrons
In order for the chlorophyll to continue to absorb light energy electrons must be replaced
They are replaced by water splitting a water molecule using light energy
This photolysis of water also yields protons
The protons are taken up by an electron carrier called NADP
When it takes up protons it becomes reduced
Reduced NADP is then passed onto the next stage with the electrons form they chlorophyl molecule
20
Q
What is the bi products of photolysis
A
Oxygen
21
Q
What is the photolysis equation
A
2H2O —>. O2 + 4H+. + 4e-
22
Q
Give a summary of the chemiosmotic theory
A
Each thylakoids is in an enclosed chamber into which protons are pumped form stroma through proton carried
Energy to drive thsubcomes form e- released by photolysis’s
Photolysis also releases protons which inc in conc. in thylakoids space
Overall creates / maintain a conc gradient of portions across the thylakoids memebrane. High in thylakoids space low in stroma
The protons can only pass the thylakoid membrane through ATP synthase channels, the rest of the membrane is impermeable to protons, these channels form small granulesnon membrane surfaces AKA staked granules
As protons pass through these atp synthases channels cause changes to the structures of the enzymes which catalyses ADP + pi to atp
23
Q
Chloroplasts adaptations
A
Thylakoids - large Sa - for attachment of chlorophyll electron carrier and enzymes that carry out light dependent reaction
Network of proteins in grana that hold chlorophyll molecules in a very precise manor that allows maximum absorbtionnofnlight
Granal mambranes have atpnsythase channel which catalysed atp production- their apps selectively permeable allowing a proton gradient
Chloroplasts have dna and ribosomes so they can quickly and easily manufacture proteins
24
Q
Who discover the light independent stage of photosynthesis, how?
A
Melvin Calvin
Used c14 and traced
25
Describe the light independent stage of photosynthesis
CO2 diffuses through stomata and dissolves in water mesophyll, diffuses through cell surface membrane of plant cell, moves through cytoplasm and diffuses into chloroplast stroma
In stroma CO2 reacts with RUBP (5c ) which is catalysed by RuBiSCo
Reaction between CO2 and RuBP. Produces 2x GP (3c)
Reduced NADP and ATP are used to reduce GP into two times GAIP (3c)
NADP reform to go back to light dependent reaction to be reduced again and except more protons
Some TP molecules converted into organic substances such as starch cellulose lipids, nucleotides amino acids
Most TP molecules are used to make/regenerate RuBP using ATP
26
How many photosytstema are in a chloroplasts
2
27
What are the 2 photosytems
1 700 (absorbed light bast at 700nm)
2 680 (absorbed light best at 680nm)
28
Carbohydrates produced by photosynthesis and not used straight away, how are they stroedb
As starch grains in the stroma
29
What 3 things is the energy form photoionisation of cholorphyll used for
Making ATP from ADP and pi, this is called phosophorylation
Making reduced NADP from NADP
Splitting water into protonsm electrons and water ( pholysis)
30
What 2 types of phosphorylation does the light dependent stage inculde
Non cyclic
Cyclic
(Each of these process Hve differnt products )
31
What does non cyclic phosophorylation produce
ATP
Reduced NADP
O2
32
What does photosytem 1 do in the light dependent stage
Light is a doves by PS1 high excite electrons again to an even higher energy level
Final the electrons are transferred to NADP aloft with protons from the stroma to form reduced NADP
33
What does cyclic photolhosphorylation produce and why
ATP
Cyclic photophosphorylation only used PS1
It’s called cyclic becasue the electrons form the chlophyll molecule arnt passed onto NADP
But are passed back to PS1 via electron carriers
This means the electrons are recycles and can repeatedly flow through PS1
This process doesn’t produce any reduced NADP or O2 - it only proves a small amount of ATP
34
What is the Calvin cycle also known as and why
Carbon dioxide fixation
Because carbon from co2 is fixed into an organic molcule
35
How are carbohydrates ( hexose sugars ) made using TP. And GP
Joining 2 TP togetehr and larger carbohydrates are made by joining hexose sugars in differn ways
36
How are lipids made using TP. And GP
Made using glycerol which is synthesised from TP and fatty acids which are synthesised from GP
37
How are amino acids made using TP. And GP
Some amino acids are made form GP
38
How many molecules of TP are made earth cycle
2
39
For every 3 turns of the cycle …. Molecules of Tp are made
…/… of these TP molecules are used to regenerate…………
6
5/6
RuBP
40
For every 3 turns of the cycle only …. TP is procured that is used to make bexose sugar
1
41
6 turns of the Calvin’s cycle need …. ATP and …. Reduced NADP
18
12
42
Anaerobic respiration in plants and yeast produce what .
Ethanol and co2
And releases energy
43
Anaerobic respiration in humans procured what’s?
Lactate and reLEases energy
44
What makes ATP. A food energy source
ATP has Specific Properties that Make it a Good Energy Source
1) AT stores or releases only a small, manageable amount of energy at a time, so no energy is wasted as heat.
2) 's a small, soluble molecule so it can be easily transported around the cell.
3) Its easily broken down, so energy can be easily released instantaneously.
4) It can be quickly re-made.
3 It can make other molecules more reactive by transferring one of its phosphate groups to them (phosphorylation).
6 ATP can't pass out of the cell, so the cell always has an immediate supply of energy.
45
What is a coenzyme
A molecule that aids the function of an enzyme
46
How do coenzymes work
Transferring a chemical group form one molecule to another
47
What is the coenzyme used in photosynthesis
NADP
NADP transfers hydrogen form one molecule to another
48
Examples of coenzymes used in respiration are
nad
Coenzyme A
FAD
………………,.,.,,.,.,.,.,.,,..,.,.,..,,..,.,,..,.,,..,,..,.,
NAD and FAD transfer hydrogen form one molecule to another -
A transfers acetate between molecules
49
Metabolic pathway definition
A series of small reaction controlled by enzymes
50
Phosphorylation Definition
Adding phosphate to a molcule
51
Photoionisation Definition
When light energy excited electrons in an atom or molecule, giving them more energy and causing them to be released, the release of electrons cause the atom or molecule to become a positively changed ion
52
Decarboxylation Definition
The removal of co2 form a molcule
53
Dehydrogenation Definition
The removal of hydrogen form a molcule
54
What do animals need energy for
Muscle contraction
Body temp regulation
Activate transport
DNA replication
Cell divison
Protein synthesis
55
Can a cell get energy directly form glucose , so
No
So energy released form glucose is used to make ATP
ATP diffused into part of cell where it is needed
56
When atp is hydrolysis
The chemical energy is released form where
The phosphate bond
57
What is the rate of photosynthesis effected by
Light intensity
Co2
Temperature
58
What is the law of limiting factors
At any given moment the rate of physiological process is limited by the factor that is at the least favourable value
59
Why is it hard to quantify photosynthesis
Level of co2 0.04%
Products of photosynthesis - hard to measure o2 in terrestrial plants
Temp changes - east to implement by rates of changes are difficult to quantity
60
When light is the limiting factor in photosynthesis the rate is a
Ways …….
Directly proportional to the light intensity
61
What is the light compensation point
It exists at the maximum amount of co2 absorbed responds to the o2 produced
Any further increase in rate would need inc co2
62
What are only certain wavelengths used in photosynthesis
Photosynthetic pig,ends chlorophyll a/b and carotene only absorbed red and blue light in the Sunlight
63
What is the optimum temp around for plants
25
64
At what temperatures are plants negatively effected and why
Photosynthesis involves enzymes (eg. ATP synthase and rubisco) if temp falls below 10°c the enzymes become inactive, move than 45° than may start to denature
Also at high temps stomata close to avoid too much water, this causes photosynthesis to slow down because less co2 enter leave when stomata are close
65
What is the optimum co2 % for photosynthesis
0.4% ( any high the stomata start to close)
66
What happens if a plant has too much water
The soil becomes water logged which reduced uptake of minerals which is needed to make chlorophyll
67
What is a saturation point
Where’s factor is no longer limiting the reaction
Something else has become the limiting factor
68
How do agriculture growers create optimum conditions for photosynthesis
Greenhouses ( glass houses)
69
How is co2 con managed in a glasshouse
Co2 is added or the air, by burning a small amount of propane in a co2 generator
70
How is light managed in greenhouses
Light can get thought glass and lamps are used at night
71
How is temperature managed in glass houses
Glasshouses trap heat energy from sunlight which warms the air, heaters and cooling systems can also be used to keep a constant optimum temperature and air air circulation system make sure the temperature is even throughout the glass house
72
Where can simsialr techniques that glasshouses used be used
Polytunnels (made of polythene, under which plants can be grown)
73
How did Calvin work out the light independent reaction
Lollipop
Algae are grown under light in thin transparent lollipop
Radioactive C14 in the form hydrogencarbonate is injected
At intervals samples on the photosynthesising algae are dropped into the hot methanol to stop chemical reactions instantly
The compound in the algae are separated by two water chromatography
The radioactive compounds are identified
74
What is an ecosystem
All the organisms living in a particular area and all the non-living (abiotic) conditions
75
What is a producer
Organisms that make their own food
76
Some of the sugars produced during photosynthesis are used in …… for what
Respiration to release energy for growth
77
Except respiration what is the rest of the glucose made from photosynthesis used for
Other biological molecules such as cellulose (in plant cells walls) these biological molecules make up the plants biomass
78
What is biomass
The chemical energy stored in a plant
79
How is energy transferred through living organisms of an ecosystem
When organisms eat other organisms ,
80
What can biomass be measures in terms of
Mass of carbon that an organism contains or the dry mass of its tissue per unit area per unit time
81
Why is dry mass uses as a measure of biomass rather than wet mass
Water content of living tissue varies
82
How is biomass measures (method)
1) dry mass is the mass of the organism with the water removed
2) to measure dry mass, a sample of the organism is dries, oftern in an oven at low temps, the sample is then weighed at regular intervals, once mass is constant you know all water has been removed
3) if needed the result can be sacked up to give the biomass of the total population or the area being investigated.
83
What is a typical unit for dry mass
Kg m-2
84
The mass of the carbon present generally is …..% of the dry mass
50%
85
Why is it usefull to give biomass over a particular time period
Biomass changes over time
86
What is atypical unit for biomass over a time period
Kg m-2 yr-1
87
How can you estimate the amount of chemical energy stored in biomass
By burning the biomass in a calorimeter
The amount of heat given off tells you how much energy is in it
88
What is chemical energy stores in biomass measured in
J or KJ
89
Describe the method to find chemical energy in biomass, by calorimeter
1) a sample of dry biomass is burnt and the energy released is used to heat a known volume of water
2) the change in temperature of the water is used to calculate the chemical energy of the dry biomass
90
What is gross primary production
The total amount of chemical energy converted form light energy by plants in a given area in a given time
91
Approx. ….% of gross primary production is lost to the environment as …… when the plants respire.
What is this called?
50%
Heat
Respiratory loss(R)
92
What is the remaining chemical energy that wasn’t lost to environment as heat called
Net primary production
(So NPP = GPP - R)
93
What is rhe net primary production
The energy available to the plant for growth and reproduction - the energy is stored in the plants biomass. It is also the energy available to organisms at the next stage in the food chain. These include herbivores and decomposers
94
T or f
Consumers also store chemical energy in their biomass
T
95
How do consumers get energy
Ingesting plant material or animals that have eaten plant materials
96
Is all the chemicals energy stored in the consumers food transferred to the next tropic level
No
97
What % of the total available energy is lost in various ways as it’s transferred to thr next tropic level
90%
98
Why is 90% of energy lost form one trophies level to the n3xt
1- not all the food is eaten (bones, roots) so the energy it contains is not taken in
2- some are indigestible so are egested as faeces
3- Some energy is also lost to the environment though respiration or excretion of urine
99
Where is the energy thatgets transferred form one tropic level to the next stores
And what is this energy called
Consumers biomass
Consumers net production
100
The net production of consumers can be calculated using what formula
N = I ( F + R)
N= net production
I= chemical energy in ingested food
F= chemical energy lost in faeces and urine
R= energy lost though respiration
101
Respiration turns
…….. energy to ……. Energy
Chemical
Kinetic
102
Photosynthesis turns
…….. energy to ……. Energy
Light enegy
Chemival enegy
103
What is an ecosystem
Group of living and non living things and the relegationshop between them
104
What Is a habitat
The place where an organism lives
105
What is a population
All the organisms of one species who love in the same place at the same time and can breed together
106
What is a community
All the populations of differnt species who live in the same place at the same time and can interact together
107
What is a niche
The role it plays within an ecosystem
108
What does a niche include
What it feeds on
What is excretes
How it reproduces
109
Can 2 species have the exact same niche in the same ecosystem
No
Differnt species have to occupy differnt niches as they would compete with each other to much
110
Biotic examples
Preditors
Disease agents
Competition
Symbiosis
111
Abiotic examples
Wind
Sun
Ph
Co2 conc
112
What are the 2 types of symbiosis
Mutualism
Parasitism
113
What is an example of mutualism
When both benefit
Fly On an elephant help take insects out, and the fly has elephants protection
114
Axample of parasitism
Tick sucking on human blood
115
Are factors in an ecosyem changing
Yes
116
T or f
Stable ecosystems are relatively consistent
T
117
Are each organisms only members of one food chain,
No they are usually members of more than one and oftern feed on differnt tropic levels in differnt chains
118
What is the average enegy transferred at each trophic level
10%
119
How is energy lost between trophic levels
Can’t digest everything ( bones)
Used in respiration
Excretion of waste material
120
What is chemical energy stored as
Up in biomass ( glucose)
121
In respiration biomass is broken down to ….
Release energy
122
What are the 3 pyramids in enegy transfer
Pyramid of biomass
Pyramid of numbers
Pyramids of enegy
123
What is the shape always for a pyramid of biomass
Will always have a pyramid shape as producer is the only one who can make biomass
124
What is calorimetry
Closed system used to calculate chemical energy stores in dry mass
125
Brief calorimetry method
1) sample of dry material weighed, burned in a sealed chamber
2) heat from combustion heats water
3) 1g of water is heated by 1°c
4) if we know vol of H20 and temp rise we can calculate envy released form the mass of burnt biomass
126
What do food chains and webs show
How energy is transferred through an ecosystem
127
What is a food chain showing
Simple lines of energy transfer.
128
What is each stage in a food chain called
Trophic level
129
What does a food web show
Lots of food chains in an ecosystem and how they overlap
130
What are decomposers
They break down dead or undigested material allowing nutrients to be recycled
131
What do most farming practices aim to increase
The amount of enegy that is available for human consumption
132
What 2 ways can farming practices increase energy available for human consumption
1j the energy lost to other organisms, eg, pests can be reduced
2j the enegy lost though respiration can be reduced
133
1j the energy lost to other organisms, eg, pests can be reduced
How does this increase enegy available for human consumption
By simplifying food webs ( getting rid of food chains that don’t involve humanism enegy losses will be reduced and the NPP of the crop will increase
134
Give 2 examples of how farmers can reduce pest numbers with chemical pesticides, and how it reduces pests
- insecticides kill insect pests that eat and damage crops. Killing insect pests means less biomass is lost form crops, so they grow larger, which means NPP is greater
- herbicides kill weeds, killing weeds can remove direct competition with the crop for enegy form the sun, it can also remove the preffered habitat or food source of the insect pests, helping to further reduce their numbers and simplify food webs
135
Aside from chemical pesticides, what else can reduce number of pests
Biological agents
136
2 examples of how biological agents reduce the number of pests
1)parasites live in or lay their eggs on pest insect. Parasites either kill the insect or reduce its ability to function.
(Eg, some wasp species lay their eggs inside caterpillars - the eggs hatch and kill the catapillers)
2) pathogenic bacteria and viruses are used to kill pests
137
Do farmers use chemical or biological methods to reduce pesticides
They use an integrated system that combine both
They combined effect reduce pest numbers even more than either methord alone, so NPP increased even more
138
How does controlling conditions livestock live in increase net production
More of their energy is used for growth and less lost through respiration
139
What is 2 example of controlling conditions of livestock in increase production
1) movement increases the rate of respiration, so animals may b be kept in pens where movement in restricted
2) the pens are often indoors and kept warm so less energy is water by generating body heat
140
What is the effect of controlling conditions of livestock
More biomass is produced and more chemical energy can be stored, increasing net production and the efficiency of enegy transfer to humans
141
What are the benefits of controlling livestock conditions
More food can be produced in a shorter space of time , oftern at a lower cost
142
What are the disadvantages of controlling livestock conditions
Ethical issues
Eg. Some people think that the conditions intensively reared animals are kept in cause the animal, pain, distress or restricts their natural behaviour so shouldn’t be done
143
What is a natural ecosystem
One that hasn’t been changed by human activity
144
What disrupts natural ecosystems recycling nutrients though food webs
Human activity
145
What is a saprobiont
A type of decomposer
146
What do microorganisms do
Feed on the remains of dead plants and animals and on their waste products, breaking them Down.this allows important chemical elements in their remaining to be recycled
147
What do saprobionts do
Secrete enzymes and digest their good externally, then absorb the nutrients they need.
148
Sacrobionts Secrete enzymes and digest their good externally, then absorb the nutrients they need.
What is thus known as
Extracellular digestion
149
Saprobions Secrete enzymes and digest their good externally, then absorb the nutrients they need.
What happens in this process
Organic molecules are broken down into inorganic ions. O staining nutrients form dead organic matter using extreaxellular digestion is known as Saprobiotic nutrition.
150
Some fungi form …… relationships with the roots or plants. What is this releationship knwo as
Symbiotic
Mycorrhizae
151
What are fungi made up of
Lord thing strands called hyphae
152
Describe fungis symbiotic relationship with plants and roots
Fungi’s hyphae connect to the plants roots
The hypha’s greatly increases the surface area of the plants root system. Helping the plant to absorb ions form the soil that are usually scarce ( eg. Phosphorus) hyphae also increase the uptake of water by the plant
In turn the fungi obtains organic compounds such as glucose form the plant
153
What do plants and animals need nitrogen for.
Making proteins and nucleic acids (DNA / RNA)
154
Can plants and animals use the nitrogen in the atmosphere
No they can use it in that from
155
What does GPP stand for
Gross primary product
156
What does gross primary product mean
The rate at which plants convert light energy to chemical energy
157
What does NPP stand for
Net primary production
158
What does net Primary production mean
Energy remaining that’s available to primary consumers as energy is lost when plants respire
159
What does R stand for
Respiratory loses
160
What is the equation for producers for primary production
NPP = GPP - R
161
What is the equation for consumers for net production
N= I - ( F + R)
162
N= I - ( F + R)
What does each the letter stand for
N= net production
I = chemical energy story of ingested food
F= energy lost in faeces and urine
R= energy lost in respiration
163
Nitrite ion
NO2. -
164
Nitrate ion
NO3. -
165
What 4 compounds contain PO4 3-
DNA
RNA
ATP
phospholipid
166
Phosphorus element
P
167
Phosphate formula
PO4 3-
168
Describe the phosphorous cycle
1. Feeding and digestion - a plant is consumed by an animal the phosphate is fixed in the plants and is broke down in the digestive system. Consumers get there phosphate form the tropic level below them.
2. Decomposition and excretion - saprobionts ( fungi / bacteria) they recycle nutrients so plants can reuse. The saprobionts break down waste form animuals and decaying organism is into organic ions that are accessible to plants again.
3. Weathering / errosion of rock - phosphorous rock broken down by wind and rain are washed into rivers - microorganism changed phosphorous to phosphate so plants can absorb or mechanical mining of rock to make fertilisers
4. Absorption - plants absorb phosphate ions through their roots through active transport
5. Sedimentation - phosphate containing organisms deposited at the bottom of lakes / rivers - > becomes new rock form deposited silt and tectonic movements pouches the new rock to the surface
6. Leaching - group water washed phosphate ions out to sea / lakes / rivers
169
What is mycorrhizal interactions
Symbiotic relation between fungi and plants.
The mycorrhizal extend plant roots with fungal hyphae, inc SA for absorption (eg. Nitrogen / p)
Inc. plants water uptake ability ( especially in low moisture conditions)
mycorrhizae contribute to plant growth, health + resistance to environmental stress
Fungi receives carbohydrates / other organic compounds form the plants
170
What is nitrogen fixation
When nitrogen gas in the atmosphere is turned into nitrogen containing compounds
171
What is ammonificiation
When nitrogen compounds form dead organisms are turned into ammonia by saprobionts, which does on to form ammonium ions
172
What is nitrification
Ammonium ions in the soul are changed into nitrogen compounds that can them be us3x by plants ( nitrates)
173
What is denitrification
When nitrates in the soil are converted into nitrogen gas by denitrifying bacteria
174
What is the nitrogen cycle
1. Nitrogen fixation
1) Nitrogen fixation
• Nitrogen fixation is when nitrogen gas in the atmosphere is turned into nitrogen-containing
compounds. Biological nitrogen fixation is carried out
by bacteria They turn nitrogen into ammonia, which goes on to form ammonium ions in solution that can then be used by plants.
• Rhizobium are found inside root nodules (growths on the roots) of leguminous plants (e.g. peas, beans and clover).
• They form a mutualistic relationship with the plants
— they provide the plant with nitrogen compounds and the plant provides them with carbohydrates.
2) 2) Ammonification
• Ammonification is when nitrogen compounds from dead organisms are turned into ammonia by saprobionts, which goes on to form ammonium ions.
• Animal waste (urine and faeces) also contains nitrogen compounds. These are also turned into ammonia by saprobionts and go on to form ammonium ions.
3) Nitrification
• Nitrification is when ammonium ions in the soil arechanged into nitrogen compounds that can then be used by plants (nitrates).
First nitrifying bacteria change ammonium ions into nitrites.
• Then other nitrifying bacteria change nitrites into nitrates.
3. Denitrification
When nitrated in the soil are converted into nitrogen gas by denitrifying bacteria - they use nitrated in the soil to carry out respiration and produce nitrogen gas
Thus happens under anaerobic conditions eg, waterlogged soil
175
Why cant plants and animals use atmospheric nitrogen
They need bacteria to convert it into nitrogen containing compounds first.
176
What are the 4 processes that involve bacteria in the nitrogen cycle
Nitrogen fixation
Ammonification
Nitrification
Denitrification
177
What is another way of nitrogen getting into an ecosystem
Lighting ( which fixes atmospheric nitrogen )
Artificial fertilisers ( they’re produced form atmospheric nitrogen on an industrial scale in the harber process )
178
What do plants and animals need nitrogen to make
Proteins and nucelic acids
179
Where is phosphorous found
In rocks and dissolved in oceans in the for, of phosphate ions
180
Phosphorus cycle
Phosphate ions in rocks are released into the soil by weathering
Phosphate ions are taken into the plants through the roots.
Mycorrhizae (see previous page) greatly increase the rate at which phosphorus can be assimilated.
Phosphate ions are transferred through the food chain as animals eat the plants and are in turn eaten by other animals
When plants and animals die, saprobionts are involved in breaking down the organic compounds, releasing phasphate ions into the soil for assimilation by plants.
These microorganisms also release the phosphate ions from urine and faeces.
Weathering of rocks also releases phosphate ions into seas, lakes and rivers. This is taken up by aquatic producers, such as algae, and passed along the food chain to birds.
The waste produced by sea birds is known as guano and contains a high proportion of phosphate ions. Guano returns a significant amount of phosphate ions to soils (particularly in coastal areas. It is often used as a natural fertiliser.
181
Crops take In minerals form the soil as they grow and then use them to …
Build up their own tissues
182
When crops are harvested, they’re removed from the field where they’re grown rather than begining allowed to die and decompose.
What does this mean for mineral ions…
The mineral They contain eg. Phosphate amd nitrates are not retired to the soil by decomposers in the nitrogen or phosphorus cycle.
183
How are phosphates amd nitrates lost form the system
When animals or animal products are removed from the land. Animals eat grass and other plants, taking in their nutrients. When they are taken elsewhere for slaughter or transfer to a differnt field, the nutrients aren’t replaced through they remains or water products
184
What do fertilisers do
Replace the lost minerals, so more energy from the ecosystem can be used for growth, increasing the efficiency of energy transfer.
185
Are fertilisers artificial or natural
Both
186
What are artifical chemicals made from,
Inorganic
They contain pure chemicals (eg. Ammonium nitrate) as powder or pellets
187
What do natural fertilisers contain
Organic matter, they include manure, composted vegetables, crop residue (the parts left over form the harvest) and sewage sludge
188
What leads to fertilisers landing into waterways
Sometimes more fertiliser is applied then the plants need or are able to use in a particular time
189
What is leaching
When water soluble compounds in the soil are washed away.
Eg. By rain or irrigation system
They are often washed into nearby ponds or rivers
190
What can leaching lead to
Eutrophication
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When is leaching more likely to occur
If The fertilisers is applied just before heavy rainfall
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Is leaching more or less likely in organic or inorganic ions
Inorganic ions, in chemical feriltizers are relatively soluble. This means that excess minerals that are not used imediatly are more likely to leach into water ways.
In natural fertilisers,the nitrogen and phosphorus are still contained in organic moelcuels that need to be decomposed by microorganism before they can be absorbed by plants.this means that there release into the soil for uptake by plants is more controlled and leaching is less likely
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Is the leaching of phosphate more or less Likely than the leachinf of nitrates and why
Less
As phosphate is less soluble
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Using fertilisers changes what about the soil?
The balence of nutrients in the soil - too much of a particular nutrient can cause crops and other plants to die
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Describe eutrophication
1. Mineral ions leached from fertilised fields stimulate the rapid growth of algae In ponds and rivers
2. Large amount of algae block lights from reaching the plants below
3. Eventually the plants die because they are unable to photosynthesis enough
4. Bacteria feed on the dead plant matter. The increased number of bacteria reduced the oxygen concentration in the water by carrying out aerobic digestion
5. Fish and other aquatic organism die because there isn’t enough dissolved oxygen
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Any change in a community of organism can cause a change in what (succession)
Their habitat
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Any change in a habitat can also cause a change in what ( succession)
Change in make up of community
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Give 2 examples of pioneer species
Lichen
Moss
Maram grass
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What is primary succession
Refers to the introduction of plants into areas that have not previously supported a community
200
What is a pioneer species
The first organism to colonise an area
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Features of a pioneer species
- early arrivals, rapid germination
- axesual reproduction
- can tolerate extreme conditions eg. Low nutrient levels
- have good means of dispersal, usually by wind
- ability to photosynthesis
- notinfluences by or dependent on animal species
- they are not able to compete for resources eg, light
- may be able to fix nitrogen (eg, leguemes) and build up soil nutrients
202
What does secondary succession refer to
The reintroduction of organisms into a bare habitat previously occupied by plants and animals
If the origional vegetation is removed the area rapidly becomes recolonised by a succession of differnt plants and animals
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How does succession happen
Eg, algae on bare rock
Errosion of the rockand build up of dead and rotting organisms produce enough soil for larger plants to grow. There replaced, or succeeded the algae
Then larger plants succeed smaller plants until a stable community is reached
This is called a climax community
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What are some features of a climax community species
- species found in the end point community
- have larger seeds ( with a large energy store) so that seedlings can survive low light intensity
- have specialised niche
- are unable to tolerate great functions in the water contents of soil
- are strongly influenced by other orgnaums, eg competitors, herbivore, pollinators, seed dispersal agents and soil microorganisms
205
Suggest abiotic factors that make colonisation plants difficult in sand dunes ( just above high tide lime)
Wind
Dry
Salt
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Explain the role of pioneer plants in succession of bare or rock or sand dunces
Stabilises environment
Inc organic material in soil
Holds more waters
Release more minerals / nutrients
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What elements do modern fertilisers contain
Nitrogen
Phosphorus
Pottasium
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Benefits of fertilisers
Allow more food to be grown on the same amount of land, support food security, to meet demands of growing population
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Negatives of excessive fertilisers (biodiversity)
Promotes fast growing species - so reduces biodiversity
Outcompeting slower-growing species so disrupts ecosystems and food chains
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Negatives of fertilisers ( leaching)
Soluble nitrates form fertilisers can leach into the ground water and surface water
Nitrates contamination affects drinking water and aquatic ecosystems
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What are the 3 negatives of fertilisers
Loss of biodiversity
Leaching
Eutrophication
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What is eutrophication
Fertilisers runoff leads to nutrient pollution in water bodies causing algal blooms
Algal blooms reduce oxygen levels, harming aquatic life and creating dead zones
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How does fertilisers link to sustainability
Optimising fertiliser use minimises ecological damage while maintains productivity
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Uses of plant other than food
Building material
Clothes
Medicines
Fuel
Livestock food
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What is a good system for plants to refix nutrients in the soil
Crop rotation
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What does the harber process do
Produces NH3,
By fixing N2 form the atmosphere
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What can NH3 from the harber process be turned into …. To be used on ….
NH4+ salts
To be used on fields as fertilisers
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Can all nutrients / fertiliser be leached
No only water soluble nutrients
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RESPIRATION
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What is the aerobic respiration symbol equation
C6H12O6 + 6O2 —> 38ATP + 6H2O + 6 CO2
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What are the 3 stages of aerobic respiration
1. Glycolysis
2. Link recation + kerbs cycle
3. Electron transfer chain
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Where does glycolysis take place
In the cytoplasm
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Is glycolysis and anaerobic or aerobic process
Anaerobic
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What are the reactants in glycolysis
Glucose
2ATP
2NAD
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Products of glycolysis
2 Pyruvate
2 ADP + Pi
2NADH
4ATP
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What is the net production of ATP for glycolysis of one glucose
2
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Explain glycolysis
1. Phosphorylation of glucose to glucose phosphate making glucose more reactive, the phosphate comes from hydrolysis of 2ATP
It activates the glucose with the energy and lowers Ea for enzyme controlled recation wich follow
2. Splitting of phosphorylated glucose. Into trios phosphate
3. Oxidation of Tp. Hydrogen is removed form each To and transferred to a hydrogen carrier called. NAD —> NADH
4. Production of ATP, enzyme controlled reactions convert each Tp into pyruvate , in process 2 ATP generated
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Where does the link reaction take place
In the mitochondrial matrix
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What are the reactants of the link reaction
2 pyruvate
2 NAD
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What are the products of the link recation
2 acetyl coA
2NADH
2CO2
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What happens in the link reaction
Pyruvate ( 3c)
oxidation of Pyruvate
And decarboxylation ( loss of Co2)
And reduction of NAD
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Reactants of kerbs cycle
2 acetyl co A
2 4carbon compounds
2 ADP + Pi
6NAD
233
Products of the kerbs cycle
4Co2
2ATP
2FAD2H
6NADH
234
Reactants if the electron transfer chain
10 NADH
2FADH2
O2
235
Products of the electron transfer chain
32 ATP
H20
236
Where does the ETC take place
In the inner mitrochondia l membrane producing many ATP
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What equation to make water happens in the ETC
2e- + 1/2 O2 + 2H+ —> H2O
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Describe the ETC in respiration
• H+ produced during glycolysis and Krebs cycle combine with NAD and FAD ( Coenzymes)
• Reduced NAD and FAD donate their electrons(from H) to the first molecule in the E.T.C.
• Energy from electrons is passed through a chain of proteins- electron transfer carrier molecules in a series of oxidation- reduction reactions.
• As electrons flow along the E.T.C. the energy they release causes the active transport of protons across the inner mitochondrial space and into the intermembrane space.
• Protons accumulate in the intermembrane space before flowing by facilitated diffusion back into the mitochondrial matrix through ATP synthase channels.
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Name 2 other energy stores fro respiration ( not glucose )
Proteins
Lipids and fats
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How can fats be used as an energy store for respiration
Fats—> fatty acids and glycerol
The glycerol is then phosphorylated to trios phosphate
The fatty acids are not wasted they are broken down into 2C fragments which are converted to coA
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How are proteins as an energy store for respiration
They are hydrolysed into their constitute amino acids, the amino acids are deaminated before entering respiratory pathway at different points depending on number of carbons
3carbon - Pyruvate
4c - 5c - intermediates in the kerb cycle
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What is the only source of ATP for anaerobic respiration and why
Glycolysis
As Kreisler and ETC can’t function without oxygen
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In animals, in anaerobic , what is Pyruvate converted unto
Lactate
244
In plants and microbes, anaerobic, what is Pyruvate converted into
Co2 and ethanol
245
anaerobic in animals equation
2 Pyruvate + 2NADH —> 2ATP + 1 lactate + 2NAD
246
when exersize stops and anaerobic respiration has occurred what needs it happen
The lactate has to be oxidised back into Pyruvate
247
Explain anaerobic respiratio
1. For respiration ot proceed Pyruvate + hydrogen form NADH have to be removed
2. Pyruvate accepts H from NADH and the NADH can be used to accept more H
3. Pyruvate is then converted Into lactate or ethanol depending on the organism
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anaerobic equation in plants and microbes
2 Pyruvate + 2 NADH —> 2ATP + ethanol + co2 + 2NAD
249
What is oxygen debt
o2 may be used to more rapidly after strenuous exersize. As if muscles still need to work despite a shortage of O2, NAD form glycologyis can accumulate and needs to be removed
250
How is accumulated NAD removed
Each Pyruvate take up the 2H atoms form NADH to make lactate
This can very oxidised later or converted into glycogen . It can be removed by blood and converted into glycogen in the liver
251
Do aerobic and anaerobic start with the same first stage
Yes
252
does glycolysis require oxygen
No
253
What is the purpose of glycolysis
Splitting one molecule of glucose into two smaller molecules of Pyruvate
254
What is the first stage of glycolysis
Glucose is phosphorylated using a phosphate from a molecule of ATP. This creates one molecule of glucose phosphate and one molecule of ADP.
ATP is then used to add another phosphate forming hexose bisohospahate
Hexose bisphospate is then split into two molecules of triose phosphate
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What is the second stage of oxidation
Triose phosphate is oxidised( looses a hydrogen ) forming 2 molecules of Pyruvate
NAD collects the hydrogen ion, forming 2 reduced NAD
4ATP are produced, but 2 were used up in stage one, so there’s a net gain of 2 ATp
256
What happens after glycolysis in anaerobic respiration
The Pyruvate is converted into ethanol ( in plants and yeast ) or lactate ( in animals and some bacteria ) using reduced NAD
257
Pyruvate to ethanol in anaerobic respiration, what is the intermediate compound once co2 is removed
Ethanal
258
The production of ethanol or lactate regenerates …..
Why is this important
NAD
This means glycolysis can continue even when there isn’t much oxygen around so a small amount og ATP can still be produced to keep some biological processes going
259
Describe the link reaction
Pyruvate is decarboxylated ( one carbon removed to form co2 )
Pyruvate us oxidised to form acetate and NAD is reduced to form reduced NAD
Acetate is combined with coenzyme A to from acetyl coenzyme A
260
How much ATP is produced in the link recation
0
261
How many link reactions happen for every glucose
2
262
What are products form the link reaction and where does it go
2 acetylc coA ( go to krebs)
Two CO2 ( waste)
2 reduced NAD ( and go to the last stage(
263
Explain the Krebs cycle
1) Acetyl coA form the link reaction combines with a 4 carbon molecule to from a 6 carbon molecule ( citrate )
CoA goes back to the link reaction to be used again
2) the 6C molecule is converted to a 5 c
Decarboxylation occurs -a co2 is removed
Dehydrogenation also occurs where hydrogen is removed
The hydrogen is used to produce reduced NAD
3) the 5c is then converted to a 4c
Decarboxylation and dehydrogenation occurs , producing one reduced FAD and 2 reduced NAD
ATP is produced by direct transfer of a phosphate group to ADP from an intermediate compound
264
What is it called when one phosphate group is directly transferred from one molecule to another
Substrate level phosphorylation
265
What is oxidative phosphorylation
Process where the energy carried by electrons, from reduced coenzymes, is used to make ATP
266
Hydrogen atoms are released from NADH and FAD2Has their oxidised , what happens to the H atom
Split into protons and electrons
267
What happen to the electrons
Move down the electron transfer chain loosing energy at each carrier
268
What is the energy lost by electrons at each carrier used for
Used by electron carrier to pump protons from the mitrochondrial matrix into the intermebrane space
269
How does rhe conc differ better matrix and Intermememrbane space
Higher in intermembrane space forming an electrochemical gradient
270
What happens when the protons have established their electrochemical gradient
Move down their electrochemical gradient, back across the inner mitochondrial memebrane and into mitrochondial matrix , via ATP synthase
This movement drives synthesis of ATP from ADP and Pi
271
The process of ATP production driven by the movement of H+ across a memebrane
Is called…
Chemiosmosis
272
What happens in the mitrochondrial matrix at the end of the transport chain
The protons, electrons and O2 ( form blood) combine to form water
273
What is said to be the final electron acceptor in ETC
Oxygen
274
How many ATP can be made from one glucose molecule
32
275
How much ATP is made from each NADH
2.5
276
How much ATP is made for, each reduced FAD
1.5
277
How does mitrochondrial disease affect ATP production
The disease affects the functioning of mitrochondia
They can affect how proteins involved in oxidative phosphorylation or the kerb’s cycle functioning, reducing ATP production
This may cause anaerobic respiration to increase, to try to make yo from some ATP shortage
This results in lots of lactate being produced , which can cause muscle fatigue and weakness
Some lactate will also diffuse into the bloodstream, leading to a high lactate concentration in the blood
