On The Wild Side

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Chloroplast

Inner membrane

Outer membrane (Chloroplast envelope)- keeps all things needed for photosynthesis close 

Starch grains 

Lamella- holds thylakoid membranes together 

Grana- stacks of thylakoid membranes 

Stroma- site of light independent reactions (calvin cycle)

Thylakoid membranes- site of light dependent reactions, large surface area and lots of atp synthase 

DNA loops 

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ATP Production

ADP + Pi = ATP photophosphorylation 

enzyme; atp synthase

ATP = ADP + Pi hydrolysis 

enzymes; atpase 

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Photosynthesis

6CO2 + 6CO2 = 6O2 + C6H12O6

Dependent    Independent    Dependent    Independent 

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Light Dependent

Happens in the thylakoid membranes- chlorophyl and electron transport molecules embedded in the membrane 

1. electrons in chlorophyl become excited due to light energy hitting the chlorophyl 

2. move along into the electron transport chain, oxidation and reduction changes electrons 

3. this causes the photophosporylation of ADP and Pi to form ATP 

4. water is split by photolysis to form, H+ ions, electrons and oxygen 

5. the electrons are used to replace ones in the chlorophyl, H+ is used to reduce nadp to produce reduced nadp, oxygen is a waste product 

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Light Independent

This happens in the stroma 

1. Carbon dioxide combines with RuBP to form a 6 carbon compound, however this is unstable and it splits into two 3 carbon compounds called GP. Rubisco acts as the catalyst in this reaction. 

2. GP is reduced to GALP, this requires energy from ATP, the energy is in the phosphate bond, so this break into ADP and Pi. It also requires H+ ions from reduced nadp, this is converted back to nadp. 

3. 12 GALP molecules are made in total, 2 GALPS are used to make Glucose, 10 GALP are therefore used to regenerate RuBP, this also requires energy from ATP. 

4. The cycle continues 

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Energy Transfer

Gross primary productivity (GPP)- rate at which energy is transferred to organic material 

Net primary productivity (NPP)- rate at which energy is transferred to biomass 

NPP = GPP - R (respiration) 

Energy loss; 

. Leaf; pass through, absorbed, evaporates or reflected 

. Not correct wavelength 

. Not all of plant eaten 

. Metabolic reactions; respiration, movement 

. Hit incorrect part of plant 

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Abundance

The number of a certain species in relation to their habitat, this includes conditions such as abiotic, biotic and anthropogenic. 

Abiotic Conditions

Solar conditions (light intensity/hours of light)

Temperarture

Topography (height of land) 

Climate

Edaphic (soil) 

Oxygen concentration 

Biotic Conditions

Parasitism 

Predication 

Competition 

Grazing 

Anthropogenic Conditions

Grazing 

Deforestation 

Fires 

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Distribution

Where a certain number of organisms are in terms of their location in accordance to other organisms of the same or different species. 

Primary Succession- newly formed habitat on not previously colonised land 

Secondary Succession- succession on a previously colonised area of land 

Deflected Succession- succession maintained by human interference 

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Succession On A Sand Dune

1. Pioneer species- colonised new land with poor nutrient content, they break up the soil forming the start of soil. Xerophytic adaptations, minimising water loss helps them survive. 

2. Couch grass- build dunes, use long roots to trap sand, grow best when buried. 

3. Marram grass- resist water loss (stomata present on inside). 

4. Variety of plant species- conditions become more favourable, nitrogen fixers improve content level of soil. 

5. Climax community- eventually trees are present, they are much more dominant than smaller plants. There is a balance of interactions between plants and animals. 

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Speciation

Formation of two new species from an original single species, due to changes in environmental pressures causing reproductive isolation. 

Gene pool- total of all allele frequency in a population 

Allele frequency- number of different alleles or gene types in a population (gene pool) 

Pre-zygotic barriers;

habitat- different area 

temperate- reproduce at different times 

mechanical- organs are incompatable

behavioural- don't respond to each others mating displays 

Post-zygotic barriers;

hybrid sterility- offspring cannot reproduce (sterile) 

hybrid inviability- offspring don't survive to reproduce 



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Evolution

Natural Selection- selective pressure put on a population, certain organisms have adaptations or mutations that mean they can survive, they reproduce and pass on their genes to their offspring. The allele for ones that can survive therefore increases. 

Evolution- gradual change in allele frequency over time 

Evidence;

1. DNA evidence- evolved from a common ancestor (DNA hybridisation, DNA profiling and DNA molecular clocks) 

2. Proteomics- the study of proteins, the closer related the proteins the closer the genetic information is (DNA) 

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Green House Gases

Methane and carbon dioxide

Absorb infrared radiation reemmited by the earths surface, causes an increase in vibrational energy and this causes a rise in temperature. This is called the Green House Effect. Increased levels causes a negative impact and increase the effects of Global warming & climate change. 

Evidence; 

Peat bogs- dead organic material from plants (carbon fixation) 

Dendrochronology- study of tree rings (wider = temperature hotter and rainfall higher)

Temperature & carbon dioxide records 

Ice cores 

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The Effect Of Global Warming

Enzymes; at high temperatures enzymes become denatured

Very below optimum; an increase in temperature causes an increase in activity 

Just below optimum; an increase in temperature causes denaturing and therefore a decrease in activity. This results in slowing and eventually stopping metabolic processes. 

Migrate; if the temperature becomes too hot species can move north or vice versa. However if they live very far north in places such as the tundra they risk extinction, they have to adapt to survive. 

Alien Species; due to migration alien species can invade habitats of already present organisms, this can pose a threat, the current species will have to adapt to survive. 

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