Energy Flow

Biology

Standards: SC.912.L.17.1, SC.912.L.17.9

Textbook: Chapter 4.1 thru 4.3

Energy Flow Outline

A. Trophic Levels and Energy Reduction (17.9)

1. Food Chains and Food Webs

2. Trophic Levels

3. Pathway of Energy Transfer

4. Energy Pyramids

5. 10% rule

B. Biogeochemical Cycles (E.7.1)

1. Law of Conservation of Matter & Energy through the Water Cycle and Carbon Cycle

OBJECTIVES

A. Trace the energy pathways through the different trophic levels of a food web or energy pyramid. (ALD)

· Analyze the role of different types of organisms in the energy pathways of a food web and determine the most efficient pathway of energy flow

· Investigate and describe the transfer of energy from one trophic level to another (10% rule)

B. Analyze and describe the movement of energy and matter through the carbon cycle and water cycle.

Vocabulary:

autotroph, heterotroph, producer, chemosynthesis, photosynthesis, consumer (primary, secondary, tertiary), decomposer, scavenger, carnivore, omnivore, herbivore, detrivore, ecosystem, food chain, food web, trophic level, apex predator, biomass, biogeochemical cycle

What is Energy Flow in ecology?

Energy flows through an ecosystem starting from the sun, then to the producers and then to the consumers. At each level, some of the energy is lost as heat.

Remember the following concepts:

Autotrophs (producers) - capture energy from environment and convert it into "food"

Heterotrophs (consumers) - must eat things

Herbivores- plant eaters

Carnivores- eat other animals

Omnivores0 eat both plants and animals

Detritivores/Decomposers- obtain energy through the decomposition/decay of organic matter (typically fungus, some bacteria and/or worms.

*SUNLIGHT is the main source of energy*

Photosynthesis (photosynthetic organisms) - uses light energy to make "food"

Chemosynthesis (chemosynthetic)- makes food from chemicals (some bacteria synthesize food in this way)

Photosynthesis

Chemical Reaction

FOOD CHAINS AND FOOD WEBS - illustrate the flow of energy in an ecosystem

*Note the direction of the arrows, they indicate where the energy is going when one organism consumes another.

*Each step in a chain or web is called a TROPHIC LEVEL

Be able to identify the following BELOW: Herbivore,s Omnivore,s Primary Consumers, Tertiary Consumers, Carnivores, Producers,

Secondary Consumers

FOOD WEB

Ecological Pyramids Biomass Pyramid

The total amount of living tissue within a given trophic level is called its biomass (usually measured in grams of organic matter per unit area).
The amount of biomass a given trophic level can support is determined in part by the amount of energy available.

A pyramid of biomass is a model that illustrates the relative amount of living organic matter available at each trophic level in an ecosystem.

Example of Biomass pyramid of Land Animals/Plants.

Ecological pyramids are models that show the relative amount of energy or matter contained within each trophic level in a given food chain or food web.

The 10% rule: Each level has ten percent less energy available to it because some of the energy is lost as heat at each level