Presentation on theme: "Carbon, Nitrogen, and H2O. Energy Flow Without a constant flow of energy, living systems cannot function. Sunlight is the main energy source for life."— Presentation transcript:
Energy Flow Without a constant flow of energy, living systems cannot function. Sunlight is the main energy source for life on Earth.
Some types of bacteria rely on the energy stored in inorganic (non-living) chemical compounds instead of the sun. These organisms use chemical energy to produce food in a process called chemosynthesis.
autotrophs, or producers, have the ability to make their own food. Most autotrophs convert light energy to chemical energy (food). They accomplish this through photosynthesis.
The bacteria that perform chemosynthesis are also autotrophs (ex: bacteria in deep sea thermal vents, hot springs, and marshes)
Heterotrophs get their energy from the things they consume (eat) or absorb. There are five major types of heterotrophs.
Herbivores – obtain energy from eating plants Carnivores – obtain energy from eating animals Omnivores – obtain energy from eating plants and animals (most humans)
Detritivores – feed on plant and animal remains and other dead matter (detritus) Decomposers – organisms that break down organic matter (once living stuff) into simple products. Generally, fungi and bacteria are the decomposers.
FOOD CHAINS AND FOOD WEBS Energy flows through an ecosystem in one direction, from the sun or inorganic compounds to autotrophs and then to many different heterotrophs.
A food chain is a series of steps in which organisms transfer energy by eating and by being eaten. Each step in a food chain or a food web is called a trophic level. There are basically four trophic levels to food chains:
Producers (autotrophs that perform photosynthesis or chemosynthesis) Primary consumers (herbivores) Secondary consumers (carnivores or omnivores) Tertiary consumers (carnivores or omnivores)
A food web shows all the food chains and relationships in an ecosystem.
Ecological pyramids An ecological pyramid is a diagram that shows the amount of energy or matter within each trophic level in a food chain or web. There are three major types of ecological pyramids.
Energy Pyramid – shows the relative amount of energy available at each trophic level.
The 10% Rule – In a food chain, only about 10% of the energy is transferred from one trophic level to the next. The other 90% is used for things like respiration, digestion, running away from predators, etc. The producers will have the most energy in an ecosystem, the tertiary consumer will have the least energy.
100% 10% 1%.1% PRODUCERS Autotrophs 1 st Level CONSUMERS Heterotrophs 2 nd Level CONSUMERS 3 rd Level CONSUMERS Copyright 2011 – Rachel Miller – No part of this presentation may be duplicated
Biomass Pyramid – represents the amount of living organic matter at each trophic level. Typically, the greatest biomass is at the bottom of the pyramid (producers).
Pyramid of Numbers – Shows the relative number of organisms at each trophic level. This is not always the same as the biomass pyramid.
Hydrological (Water) Cycle Water vapor is transferred into clouds through condensation, which leads to precipitation (rain, snow, sleet, hail).
The process by which water changes from liquid to water vapor is called evaporation.
Water can also enter the atmosphere by evaporating from the leaves of plants in a process called transpiration.
Carbon Cycle Animals and plants add carbon dioxide (CO2) to the atmosphere through respiration. Plants take in the atmospheric CO2 to use during photosynthesis.
When plants and animals remove waste or die, the carbon in their bodies enters the soil. Over millions of years the carbon is turned into fossil fuels.
Humans release carbon dioxide into the atmosphere when they burn fossil fuels, mine coal, and cut or burn forests.
Since the industrial revolution, the levels of atmosphere CO2 have steadily risen. Which has lead to an increase in the greenhouse effect.
Greenhouse effect – when heat is trapped in the Earth’s atmosphere by carbon dioxide, methane and other greenhouse gases. A drastic rise in greenhouse gases could increase the greenhouse effect and lead to global climate change.
Nitrogen Cycle Most of the Earth’s nitrogen exists as atmospheric nitrogen (N2). Plants and animals cannot use this form of nitrogen.
Atmospheric nitrogen (N2) is transferred to the Earth’s soil by precipitation. Once in the soil, special bacteria in plant roots convert N2 into ammonia in a process called nitrogen fixation.
Other bacteria in the soil then change the ammonia into nitrate or nitrite. Producers (plants) and animals use the nitrate or nitrite to make proteins.
When organisms die, decomposers return the nitrogen to the soil as ammonia.
Other bacteria convert nitrates back into atmospheric nitrogen (N2) in a process called denitrification.