On the Wild Side Flashcards
1
Q
what do plants use to produce glucose?
A
- the suns energy
- through photosynthesis
2
Q
Why are plants autotrophs?
A
- because they do not need to feed to gain energy
- animals are heterotrophic
3
Q
What are the other examples of autotrophs?
A
- Purple sulphur bacteria
- uses hydrogen sulphide and heat energy to make sugar
- these are known as chemosynthetic autotrophs
4
Q
What is chlorophyll?
A
- one of several photosynthetic pigments
5
Q
What are the three types of photosynthetic pigments?
A
- chlorophyll a
- chlorophyll b
- carotenoids
6
Q
Describe the structure of chlorophyll A and B
A
- hydrophilic head
- Mg2+ at the centre of a PORPHYRIN ring structure
- hydrophobic tail
- made of a hydrocarbon chain that anchors the molecule into chloroplast membrane
7
Q
What is the difference between chlorophyll A and B
A
- A has a CH3 group attached to porphyrin ring structure
- B has a CHO group attached to porphyrin ring structure
8
Q
What are carotenoids?
A
- red, orange, yellow pigments
- hydrophobic
- membrane attached
= accessory pigments
- assist chlorophyll a+b by passing on light to them
9
Q
All photosynthetic pigments absorb…… light
A
Blue
10
Q
What wavelengths can carotenoids not use?
A
- longer wavelengths in the yellow to red part of the spectrum
11
Q
What are the best light colours for photosynthesis?
A
- blue and light red
- plants have several pigments to absorb as much light as possible
12
Q
Why are leaves not black
A
- as they will get too hot and enzymes will denature
13
Q
What is the function of the outer membrane of chlorophyll?
A
- allows free passage of CO2, O2, H2O
14
Q
Describe the inner membrane of chlorophyll
A
- contains many transporter proteins
15
Q
What is the thylakoid membrane?
A
- interconnected, flat, fluid-filled sacs of membrane
- membrane contains photosynthetic pigments
- light dependent reaction occurs here
16
Q
What is the granum?
A
- stacks of thylakoids
17
Q
What is the stroma?
A
- the fluid surrounding thylakoids
- light independent reaction occurs here
18
Q
Where are photosynthesis products stored?
A
- in the starch granule
19
Q
What is the DNA loop?
A
- chloroplast dna coding for some proteins
20
Q
A
21
Q
Where do light dependent reactions take place?
A
Photosytems 1+2 in the thylakoids membrane
22
Q
What do light dependent reactions do?
A
- produce ATP to supply energy for synthesis of carbohydrates
- production of NADPH to supply H+ for synthesis of glucose
23
Q
What does the light dependent reaction look like
A
24
Q
What does the light dependent reaction look like
A
25
What is ATP?
- adenosine triphosphate
- transport of chemical energy
26
Describe the formation of ATP
= condensation reaction
- nucleotide w/ two extra phosphate groups reacts with energy and Pi to form ATP
27
Describe another type of ATP reaction
= hydrolysis reaction
- ATP uses ATPase and H2O to go to a nucleotide with two phosphate groups attached, H+, a phosphate group and energy
28
Where does the energy released in the hydrolysis of ATP come from?
- energy is released as Pi gets hydrated (forming new bonds)
29
What is NADPH?
= nicotinamide adenine dinucleotide phosphate
- coenzyme
- functions as a reducing agent by carrying hydrogen
30
What are photosystems I and II
- reaction centres = chlorophyll a
- accessory pigments pass light energy to reaction centres
31
What is the difference between photosystem 2 and 1
- photosystem 2 absorbs light with wavelengths of ~680nm
- photosystem 1 absorbs light with wavelength of 700nm
32
Describe the light dependent reaction
1. PS 2 P760 reaction centre emits 2 excited electrons which pass to an electron acceptor (cytochrome) which are reduced
2. The electrons lost from PS 2 are replaced by the photolysis of H2O which produces 2H+ ions, 2 free electrons and 1/2 O2
3. The e- then pass to a series of e- carriers along an electron transport chain. Each carrier becomes reduced, then oxidised as it passes the e- on.
4. Each e- carrier has a lower energy level than the last one, so as e- pass on, energy is released which is used to synthesises ATP in a reaction called photophosphorylation
5. PS I’s P700 reaction centre has also emitted 2 excited e-. These are replaced by the 2 e- from PS II electron transfer chain
6. Electrons emitted from PS I are captured by an acceptor and passed down another chain of e- carriers
7. 2 e- combine with H+ from H2O to reduce NADP+ to. NADPH
33
what is the function of Light independent reactions?
- to use NADPH and ATP to reduce CO2 to produce glucose in a series of reactions called the Calvin Cycle
34
Describe the Calvin cycle
1. CO2 fixation
- CO2 combines with Ribulose Triphosphate (RuBP) to form 2x gylcerate 3-phosphate (GP)
- catalysed by enzyme RuBisCO
2. Reduction
- GP is reduced (picks up hydrogen) to form gyleraldehyde 3-phosphate (GALP)
- hydrogen for reduction is from NADPH
- energy for reaction is from ATP
3. Regeneration of RuBP
- GALP is used to resynthesise RUBP and produce glucose
(12 x GALP -> 6x RuBP + 1x glucose)
35
What is an anthropogenic factor?
- factors arising from human activity that affect survival
36
What is a biosphere
- global ecosystem, all organisms on earth
37
What is a biome?:
- major ecosystem on earth
38
What is succession?
- the process by which communities of organisms colonise an area and then over time are replaced by other, usually more varied, communities
39
Primary succession
= Succession on inorganic surface devoid of any vegetation (e.g bare, rock, sand, water)
40
What is stage 1 of succession
- pioneer species
- help break down ruck surface
- rock grains and dead organic matter form soil
41
What enables mosses to grow at early stages of succession
- not vascular - no xylem/phloem
- always have to be in wet areas
42
What is stage 2 of succession?
- intermediate species (grasses, ferns, non woody plants)
- establish root system in soil
- soil system develops (more water and nutrient retained) allowing other plants to survive
43
What is stage 3 of succession
- climax community (dominant)
- remains unchanged unless conditions change
- forest species - influence rest of community
44
Sand is…
- unstable
- lacks organic matter
- dries out quickly
- very salty
45
What are pioneer plants on embryo dunes?
xerophytes
- withstand drying out and sand tolerant
46
What is an example of a treeless climax community
Keen of Hamar Shetland Islands
47
Why doesn’t succession in the keen of hamar not progress further?
- drainage is so good that is often in drought
- rich in biodiversity with many rare species
48
Why wont the sphagnum moss bog in Scotland progress to a forest?
- too cold and windy
49
What is secondary succession?
- development of an ecosystem from existing soil that has been cleared of vegetation
50
What are the 3 examples of secondary succession?
1. Flood
2. Fire
3. Deforestation
51
Describe the first organisms in secondary succession
- seeds of many plant species will already be lying dormant in the soil (as a seed bank) or brought by animals or wind
- species that are best adapted will grow and survive
52
Compare primary and secondary succession
- soils already in place
- faster than primary
- different pioneer species
53
What is deflected succession?
= a community that is kept stable by human activity which prevents succession from running its course
54
What are examples of deflected succession?
1. Planting crop plants
2. Grazing
3. Mowing
4. Burning heather
55
How is planting crop plants deflecting succession?
- replaces original seeds/competition
56
How does grazing/mowing stop succession
- clips any new/germinating growth h
57
What is burning heather?
- stops it becoming too dense and difficult to walk on
- stimulates fresh growth which animals can feed on
- provides sites for birds to nest in
- increased number of niches (therefore biodiversity( by deflecting succession
58
What is a primary consumer
- herbivores-eat photosynthetic material
59
Secondary consumer
- carnivores - feed on herbivores
60
Tertiary consumer
- top carnivores - feed on herbivores and other carnivores
61
What are autotrophs
- photosynthetic or chemo synthetic organisms
62
What are heterotrophs
- consumers of other organisms
63
What are omnivores
- feed on photosynthetic organisms and animals
64
What is a trophic level
- feeding level
65
What is a food chain
- diagram showing a simple linear feeding relationship
66
What is a food web
- diagram showing complex feeding relationships (representing all organisms in an ecosystem)
67
What are detritivores
- primary consumers that feed on dead organic matter (woodlice, earthworms)
68
What are decomposers
- bacteria and fungi that feed on dead organic matter (detritus) and faeces; recyclers of nutrient
69
What is primary productivity
- rate at which energy is incorporated into organic molecules
I.e rate of photosynthesis
70
Describe the proportions of energy being transferred into a leaf
5% reflected
50% used to evaporate water
40% absorbed by chlorophyll
5% transmitted through leaf
71
Describe the proportions of energy transfger by chlorophyll
40% absorbed overall
20% not a useful wavelength
5-8% PS products
2-5% becomes new biomass
3-5% used in respiration
72
What are the limiting factors to PS?
- light
- CO2 from air
- water from soil
- temperature (affects kinetic energy of molecules)
73
What is gross primary productivity (GPP)
= the rate at which energy is incorporated into organic molecules (i.e rate of PS)
- expressed as units of energy per unit area per year
- can be used to calculate the % effiency of PS
74
What is NPP
Net primary productivity
= the rate at which energy is incorporated into organic molecules that make up new biomass
75
What is the equation for NPP
NPP = GPP - R
76
How much energy is lost from the sun to the leaf?
5-10%
77
How much energy is passed from leaf to caterpillar
Through biomass
2-10%
78
How much energy is passed from animal to animal
5-20%
Through biomass
79
How is energy lost between trophic levels?
- respiration
- dead matter + faeces which goes to decomposers
80
What is secondary productivity?
- the rate at which energy is used to make new consumer biomass
81
Give the equation for energy consumed
Energy consumed = energy lost in respiration + energy lost in waste + energy in biomass
82
Which factors affect how much energy is lost in respiration?
- surface area:volume ratio
- time spent foraging for food
- temperature of environment
- digestibility of food
83
Which factors affect how much energy is lost in respiration?
- surface area:volume ratio
- time spent foraging for food
- temperature of environment
- digestibility of food
84
What is the LDR?
H2O + ADP + Pi +NADP+ -> O2 + ATP + NADPH + H+
85
What is the LIR
CO2 + ATP + NADPH + H+ -> C6H12O6 + 6H2O + ADP + Pi + NADP+
