ECOLOGY
• Ecology coined by Haekel.
• Father of ecology- E.P. Odum.
• Warming employed termed ecology for study of plants.
• Autecology- Relation of individual species to its environment.
• Synaecology- Relation between communities and environment.
• Allopatry- Individual of same species present on different geographical location and have developed different morphological characters.
• Sympatry- Individuals of same species present on same geographical location but have developed variation in morphological characters due to reproductive isolation.
• Ecotype- Individuals of same species which have developed various morphological characters for local adaptation.
• Ecads/ Ecophene- Individuals of same species having various morphological characters ( variation are environmentally based rather than genetically)
• Ecotone- Transition zone between two communities.
• Estuary- Transition between fresh and saline water.
• Ecological niche- Word given by Grinnel. Habitat and function of every organism in an ecosystem.
• Key-stone species- Species which influence ecosystem and determine its properties.
• Phylotrom- Plant grown under controlled environment.
• Sun loving plants- Heliophytes/ Photophilous plants.
• Shade loving plants- Sciophytes/ Photophobic plants.
• Hekisthotherm- Plants growing on extremely low temperature.
• Pedology- Study of soil.
• Loam soil is best soil for plant growth.
Holart= Chesard + Echard
Chesard
↓
Available water for plant
• Psammophytes- Plants growing on sandy soils.
• Psychrophytes/ Cryophytes- Plants growing on cold soils.
• Eremophytes/ Xerophytes- Plants growing on desert/ dry soils.
• Mutualism(+, +) or symbiosis: eg. Termites and Flagellates (Trichonyma)
• Commensalism(+,0): eg. Lianas, Epiphytes, Sucker fish( Echeneis)-shark ↓
Velamen tissue is characteristics of roots of ephiphytes.
• Photo-co-operation(+/+): Both benefitted but can live separately.
• Parasitism(+/-)
Ecosystem
• Term ecosystem coines by A.G. Tansley.
• Father of ecosystem- E.P. Odum
Ecological Pyramid:
• Formed first by Elton.
• Pyramid of number inverted for tree ecosystem and pyramid of biomass inverted for pond ecosystem, inverted( Pond, forest, grassland and tree ecosystem)
• Pyramid of energy is always upright.
• At every successive tropic level, usually % energy is conserved. This is also called 10% energy conservation law by Lindeman.
• Pioneers are submerged hydrophytes in hydrosere and in crutose (lichen) in Lithosere.
• Endangered- Species in immediate danger of extinction.
• Vulnerable- Species likely to move into endangered category.
• Rare- Species which are not at present endangered and vulnerable but are at risk.
• Threatened- Species which are in one of the categories 'endangered', 'vulnerable' and 'rare' and need to be protected.
Pollution
• Fly ash is absent in automobile exhausts.
• Absence of lichens indicates atmospheric pollution by So2.
• Two primary pollutants, nitrogen oxides and hydrocarbons react together in presence of sunlight to form secondary pollutants called Peroxyacetyl Nitrate (PAN).
Troposphere- Lowest (upto 10km)
Stratosphere- O3 maximum (10-50km)
Mesosphere- (50-85 km)
Thermosphere- ( 85-500 km)
Exosphere- (beyond 500 km)
Inter-stellar space
• Photochemical smog- Los Angeles Smog, constitutes of nitrogen oxides, carbon monoxide and secondary pollutants such as O3 and HCHO. (PAN also included)
• Pollutants released by jet planes are aerosols.
• Green house effect is mainly due to carbon- dioxide.
• Pollen grain of Amaranthus plant causes air pollution.
• Mercury poisoining is from fish from Minamata Bay so also called Minamata disease.
• Eutrophication causes reduction in dissolved oxygen.
• In polluted lake , index of pollution is Daphnia. Bhopal Gas Tragedy occurred on 3rd Dec 1984 in which MIC(Methyl isocyanate) leaked out causing death of about 2500 persons.
PHOTOSYNTHESIS
Carbon assimilation(collection), Reduction, Endothermic, Anabolic, Co2 reduction, H2O oxidation
Aristotle- Photosynthesis observed
Von Helmont- Water essential
Joseph Priestly- Purification of water (CO2 taken, O2 released)
Jan Ingen Housz- Sunlight essential
Emerson- Used visible light (380-760 nm wavelength)
Engelman- Action spectrum (rate R>B>Y>G)
Emerson and Arnold- Photohemical cycle in light reaction
Van Niel- In bacteria CO2 taken but O2 not produced
Robert Hill- Proposed H2O to be source of O2
Blackman- Dark reaction, found light and dark as two steps
Quantasome- 280 pigments(50 carotenoids, 230 chlorophyll)
Carotenoids protect chlorophyll against photooxidation and transfer energy to chlorophyll
Chlorophyll- Contain Mg as central atom
Porphyrin ring (Hydrophilic) and phytol chain(Hydrophobic)
Chl-a C55H72O4Mg (contain –CH3 at 3rd of 2nd pyrol ring)
Chl-b C55H70O6Mg (contain –CHO at 3rd of 2nd pyrol ring)
| Cyano-bacteria + Higher plants | Bacteria and few red algae | |
| Non-cyclic | Cyclic | |
| Wavelength | Common light | Infra-red |
| Primary acceptor | 2 | 1 |
| Pigment system | PSI + PSII | PSI |
| Photolysis of water | yes | No |
| Oxygen | yes | No |
| Source of e-/H+ | H2O | PSI |
| Terminal acceptor of e-/H+ | NADP | PSI(only e-) |
| Production H2O O2 ATP NADH2 | 2 1 1 2 | No No 2 1 |
Calvin cycle(83%)- first observed in Chlorella
C1- CO2
C3- Pgal, DHAP(simplest organic, first and most stable)
C4- Erythrose
C5- Ribose, Ribulose, Xylulose
C6- Fructose, Glucose(by product)
C7- Sedoheptulose(most complex)
If RuBP take O2 instead of CO2 3PGA+phosphoglycolic acid is formed
Phosphoglycolic acid---> Glycolic acid---> Glycine(after entering peroxisome from chloroplast)------------------>Serine(after entering mitochondria from perioxisome) +CO2+NH2
C4 cycle
CAM cycle
Deacidification occurs in CAM cycle during day time.
C4 cycle
- Kranz anatomy
- Dimorphic chloroplast
| Optimum temperature | CO2:NADH2:ATP | Photorespiration | |
| C3 cycle | 25-350C | 1:2:3 | Usually present |
| C4 cycle | 35-450C | 1:2:5 | Completely absent |
| CAM cycle | 450C | 1:2:5 | Usually absent |
C4 cycle-
Sugercane, Maize, Grasses, Tropical plant
Common in monocot, rare in dicot like Amaranthus
Chenopodium, Athernanthera
CAM cycle-
Bryophyllum, Orchidaceae, Desert plant, Succulent plant, Agave, Cactus, Pineapple
C3 cycle-
Chlorella, Algae, Bryophyte, Pteridophyte, Gymnosperm
Common in dicot and rare in monocot like rice, wheat, barley, oat
Antiplex(both C3 and C4)
Upto 10% light is utilized in sugarcane and 8% light utilized in Oenothera- claviforms(winter evening- primrose)
RESPIRATION
Oxidation, exothermic, catabolic
Order of substrate- Carbohydrate>lipid>fat>protein
Floating
Glycolysis
Anaerobic glycolysis- 2ATP
Aerobic glycolysis- 6/8 ATP
| Found by | Step | Irreversible | Enzyme | Oxidation | Produced | |
| Glycolysis or EMP Pathway | Embden, Meyerhof Parnas | 10 | 3 | 9 | 1 | 4ATP, 2ADP, 2H2O, 2NADH2, 2 pyruvic acid |
| Kreb’s cycle | Kreb | 10 | 3 | 9 | 4 | 3NADH2 X2 FADH2 X2 2CO2 X2 1GTP X2 |
Oxidative decarboxylation
Kreb’s cycle
α-ketoglutaric acid is only 5C compound(most stable)
Citric acid- First, most stable and most complex compound
Succinate dehydrogenase- only membrane bound enzyme of mitochondria
3NADH2 ------------------------------------------------> 11 22
FADH2
2CO2
1ATP
1H2O
12 24
Decarboxylation-2
Substrate phosphorylation-1
Dehydrogenation-4
Oxidation-4
Oxidative phosphorylation or ETS
Occurs in oxysomes and all enzymes of ETS are found in F1 particles of mitochondria.
There are 2 Co-enzymes and 5 cytochromes.
ATP produced here= 10X3 (NADH2) + 2X2 (FADH2)
= 34(Malate-aspartate shuttle)
= 32 (glycerol-aspartate shuttle)
Malate aspartate shuttle is common is prokaryotes, heart cell, kidney cells, liver cells.
Efficiency = aerobic:anaerobic= 18:1/19:1
Water is terminal product of respiration.
HMP Pathway- 12NADPH2, 35ATP produced
(1 ATP is used in phosphorylation of glucose)
2 Pyruvic acid --------------------- muscle cell ------------------------> Lactic acid
-----------------------lactobacillus ------------------------> Lactic acid+ethanol+CO2
----------------------acetobacter------------------------>2Acetic acid+CO2
----------------------yeast------------------------> 2ethanol+2Co2
-----------------------bacillus butyricus------------------------> Butyric acid+2CO2
Respiratory quotient
CAM plant-0
Carbohydrate-1
Lipid-0.7
Protein-0.9
Anaerobic respiration- infinity
WATER RELATION
Father of plant physiology- Stephan Hales
OP of pure water is considered zero. OP is always positive for solution.
Water potential for pure water is zero and addition of solute in it decreases its water potential.
Water potential= -DPD
DPD never become negative.
In case of fully turgid cell, DPD=0.
DPD= OP-TP (OP>TP)
Osmosis takes place from low DPD to high DPD.
- Movement of solute/minerals-----------------> Diffusion(higher to lower) eg. Living/non-living
- Movement of solvent ----------------->Osmosis----------------->Solute(lower to higher) and solvent (higher to lower)
- Movement of Solution/liquid----------------->Imbibition(wetter to drier) eg. Dead, cell wall, seed coat
Water imbibitions in decreasing order(capacity)
Agar>Protein>Starch>Cellulose>Lignin
- When cell is kept in hypotonic (Gain of solvent, volume increases, endo-osmosis, brust due to TP, Water potential increases, DP increases, DPD decreases, SP increases)
- In isotonic(No gain, no loss)
- In hypotonic (Loss of solvent, volume decreases, exo-osmosis, plasmolysis leading to death, Water potential decreases, DP, decreases, DPD increases, SP increases)
Active transport----------------->Root active
Passive transport----------------->Shoot active
Guard cell
- Open----------------->turgidity increases, K+ increases, H+ decreases, Acidity decreases, pH increases
- Close----------------->turgidity decreases, K+ decreases, H+ increases, Acidity increases, pH decreases
Subsidiary cell
- Open-----------------> turgidity decreases, K+ decreases, H+ increases, Acidity increases, pH decreases
- Close-----------------> turgidity increases, K+ increases, H+ decreases, Acidity decreases, pH increases
Exudation of water from leaf margin----------------->Guttation
Exudation of water from leaf incision----------------->Bleeding
Guttation occurs by root pressure through hydathodes and the lost water is impure.
Enzyme connected to opening and closing of stomata is PEP carboxylase.