Ecosystems

Definition - The division of a biome through which energy flows and nutrients and molecules cycle

Flow of energy

1.        The flow of energy through ecosystems is the most important aspect of their organization

2.       Of the solar energy that reaches the earth’s surface an estimated .1% is diverted into living systems

3.       This fraction results in the productivity of the world biomes

4.       The flow of energy on earth occurs through levels or organisms in the environment

Trophic levels

1.        Producers – organisms that are able to transform light energy or chemical energy into useable energy in the cell.

Gross productivity – The rate at which energy is assimilated by an organism.  The total amount of energy from sunlight to chemical energy in the case of a photoautotroph ( plants and algae)

Net productivity – The gross productivity – the cost of metabolic activities

Biomass – dry weight of a crop or organism being studied

Net Primary production – Standing crop at the end of the growing season ( agricultural term

2.       Consumers – Energy enters he world through the producers and is passed along to herbivores who eat the producers

Primary consumers – herbivores -A fraction of the energy consumed is converted to biomass.    The remainder is lost through respiration

Secondary consumers – carnivores – eat the herbivores- more energy is lost to the system and used for survival( predators – high cost )

Higher level consumers – depend upon the base of the trophic levels below.  Only a few in every ecosystem

Decomposers –Recycle nutrients and energy through the trophic levels

Detrivores – consumers who are scavengers

For Food Web and Food Chain complete the activity in your BIOZONE HANDOUTS

Food chain –  Shows a succession of organisms from producers to consumers to decomposers – linear chain

Trophic level- producer

Primary consumer

Secondary consumer

Tertiary consumer or higher level of consumer

Food web – Diagrams all of the interactions that occurs between the food chains in an ecosystem

Pyramids of – Show relationship between trophic levels in a pyramid

Complete your BIOZONE SHEETS

Productivity

Biomass

Numbers

PHOTOSYNTHESIS

Photosynthesis – Photoautotrophs

Pigments – Capture solar energy.  Chlorophyll A ( primary photosynthetic pigment)

Chloroplasts- organelles containing photosynthetic pigments in eukaryote cells

Stroma – Cytoplasmic portion of the chloroplasts

Thylakoids and Grana – Membranous interior of chloroplasts

Accessory pigments – chlorophyll B, carotene, xanthophylls

THLAKOIDS – LIGHT DEPENDENT REACTION

Light Dependent reaction – First reactions in photosynthesis.  Pigments traps solar energy.  Energy flow to a reaction center.  In the reaction center a series of steps begins

PHOTOLYSIS – splitting water                                                 H+ and  O2

H+ - proceed to electron transport chain and a series of REDOX reactions

REDOX= Oxidation and Reduction

Photosystem II – produces ATP

Photosystem I – NADPH

STROMA – LIGHT INDEPENDENT REACTION

Uses the ATP and NADPH from the Light Dependent reaction

Light independent reaction – Calvin Cycle – BIOSYNTHESIS – the production of all of the macromolecules of life

This involves Carbon fixation – CO2 is taken in through the stomates and used for the synthesis of macromolecules