Energy Flow. ENERGY Energy is the ability to do work and transfer heat. Kinetic energy – energy in motion heat, electromagnetic radiation Potential

Energy FlowEnergy Flow

ENERGYENERGYEnergy is the ability to do work and

transfer heat.Kinetic energy – energy in motion

heat, electromagnetic radiationPotential energy – stored for possible use

batteries, glucose molecules

Energy is the ability to do work and transfer heat.Kinetic energy – energy in motion

heat, electromagnetic radiationPotential energy – stored for possible use

batteries, glucose molecules

Electromagnetic SpectrumElectromagnetic Spectrum

Many different forms of electromagnetic radiation exist, each having a different wavelength and energy content.

Many different forms of electromagnetic radiation exist, each having a different wavelength and energy content.

Figure 2-11

Fig. 2-11, p. 43

Sun

Nonionizing radiationIonizing radiation

High energy, shortWavelength

Wavelength in meters(not to scale)

Low energy, longWavelength

Cosmicrays

GammaRays

X raysFar

infrared waves

Nearultra-violetwaves

VisibleWaves

Nearinfraredwaves

Farultra-violetwaves

Micro-waves

TVwaves

RadioWaves

Electromagnetic SpectrumElectromagnetic Spectrum

Organisms vary in their ability to sense different parts of the spectrum.

Organisms vary in their ability to sense different parts of the spectrum.

Figure 2-12

Fig. 2-12, p. 43

Ener

gy e

mitt

ed fr

om s

un (k

cal/

cm2 /

min

)

Wavelength (micrometers)

Ultr

avio

let

Visible

Infrared

ENERGY LAWS: TWO RULES WE CANNOT BREAK

ENERGY LAWS: TWO RULES WE CANNOT BREAK

The first law of thermodynamics: we cannot create or destroy energy. We can change energy from one form to

another. The second law of thermodynamics: energy

quality always decreases. When energy changes from one form to

another, it is always degraded to a more dispersed form.

Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form.

The first law of thermodynamics: we cannot create or destroy energy. We can change energy from one form to

another. The second law of thermodynamics: energy

quality always decreases. When energy changes from one form to

another, it is always degraded to a more dispersed form.

Energy efficiency is a measure of how much useful work is accomplished before it changes to its next form.

Fig. 2-14, p. 45

Chemicalenergy(food)

Solarenergy

WasteHeat

WasteHeat

WasteHeat

WasteHeat

Mechanicalenergy

(moving,thinking,

living)

Chemical energy

(photosynthesis)

Producers: Basic Source of All Food


Most producers capture sunlight to produce carbohydrates by photosynthesis:

Most producers capture sunlight to produce carbohydrates by photosynthesis:



Chemosynthesis:Some organisms such as deep ocean

bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas .

Chemosynthesis:Some organisms such as deep ocean

bacteria draw energy from hydrothermal vents and produce carbohydrates from hydrogen sulfide (H2S) gas .

Photosynthesis: A Closer Look

Photosynthesis: A Closer Look

Chlorophyll molecules in the chloroplasts of plant cells absorb solar energy.

This initiates a complex series of chemical reactions in which carbon dioxide and water are converted to sugars and oxygen.

Chlorophyll molecules in the chloroplasts of plant cells absorb solar energy.

This initiates a complex series of chemical reactions in which carbon dioxide and water are converted to sugars and oxygen.

Figure 3-A

Fig. 3-A, p. 59

Sun

Chloroplastin leaf cell

Light-dependentReaction

Light-independentreaction

Chlorophyll

Energy storage and release(ATP/ADP)

Glucose

H2O

Sunlight

O2

CO2

6CO2 + 6 H2O C6H12O6 + 6 O2

Consumers: Eating and Recycling to Survive

Consumers: Eating and Recycling to Survive

Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their remains. Herbivores

Primary consumers that eat producers Carnivores

Primary consumers eat primary consumers Third and higher level consumers: carnivores that eat

carnivores. Omnivores

Feed on both plant and animals.

Consumers (heterotrophs) get their food by eating or breaking down all or parts of other organisms or their remains. Herbivores

Primary consumers that eat producers Carnivores

Primary consumers eat primary consumers Third and higher level consumers: carnivores that eat

carnivores. Omnivores

Feed on both plant and animals.

Decomposers and DetrivoresDecomposers and Detrivores

Decomposers: Recycle nutrients in ecosystems. Detrivores: Insects or other scavengers that feed on

wastes or dead bodies.

Decomposers: Recycle nutrients in ecosystems. Detrivores: Insects or other scavengers that feed on

wastes or dead bodies.Figure 3-13

Fig. 3-13, p. 61

Scavengers

Powder broken down by decomposers into plant nutrients in soil

Bark beetle engraving

Decomposers

Long-horned beetle holes

Carpenter ant

galleries

Termite and carpenter ant work Dry rot fungus

Wood reduced to powder

MushroomTime progression

Aerobic and Anaerobic Respiration: Getting Energy for Survival


Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy they need.

This is usually done through aerobic respiration. The opposite of photosynthesis

Organisms break down carbohydrates and other organic compounds in their cells to obtain the energy they need.

This is usually done through aerobic respiration. The opposite of photosynthesis



Anaerobic respiration or fermentation: Some decomposers get energy by breaking

down glucose (or other organic compounds) in the absence of oxygen.

The end products vary based on the chemical reaction:

Methane gas Ethyl alcohol Acetic acid Hydrogen sulfide

Anaerobic respiration or fermentation: Some decomposers get energy by breaking

down glucose (or other organic compounds) in the absence of oxygen.

The end products vary based on the chemical reaction:

Methane gas Ethyl alcohol Acetic acid Hydrogen sulfide

Two Secrets of Survival: Energy Flow and Matter Recycle

Two Secrets of Survival: Energy Flow and Matter Recycle

An ecosystem survives by a combination of energy flow and matter recycling.

An ecosystem survives by a combination of energy flow and matter recycling.

Figure 3-14

ENERGY FLOW IN ECOSYSTEMSENERGY FLOW IN ECOSYSTEMS

Food chains and webs show how eaters, the eaten, and the decomposed are connected to one another in an ecosystem.

Food chains and webs show how eaters, the eaten, and the decomposed are connected to one another in an ecosystem.

Figure 3-17

Fig. 3-17, p. 64

Heat

Heat

Heat

Heat

Heat

Heat Heat Heat

Detritivores (decomposers and detritus feeders)

First Trophic Level

Second TrophicLevel

Third Trophic Level

Fourth Trophic Level

Solar energy

Producers(plants)

Primary consumers(herbivores)

Secondary consumers(carnivores)

Tertiary consumers(top carnivores)

Food WebsFood Webs

Trophic levels are interconnected within a more complicated food web.

Trophic levels are interconnected within a more complicated food web.

Figure 3-18

Fig. 3-18, p. 65

HumansBlue whale Sperm whale

Crabeater seal Elephant seal

Killer whale

Leopard seal

Adelie penguins Emperor

penguin

Petrel FishSquid

Carnivorous plankton

Krill Herbivorous plankton

Phytoplankton

Energy Flow in an Ecosystem: Losing Energy in Food Chains

and Webs

Energy Flow in an Ecosystem: Losing Energy in Food Chains

and Webs In accordance with the 2nd law of

thermodynamics, there is a decrease in the amount of energy available to each succeeding organism in a food chain or web.

In accordance with the 2nd law of thermodynamics, there is a decrease in the amount of energy available to each succeeding organism in a food chain or web.

Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs

Energy Flow in an Ecosystem: Losing Energy in Food Chains and Webs

Ecological efficiency: percentage of useable energy transferred as biomass from one trophic level to the next.

Ecological efficiency: percentage of useable energy transferred as biomass from one trophic level to the next.

Figure 3-19

Fig. 3-19, p. 66

Heat

Heat

Heat

Heat

Heat

DecomposersTertiary

consumers(human)

Producers(phytoplankton)

Secondaryconsumers

(perch)

Primaryconsumers

(zooplankton)

10

100

1,000

10,000Usable energy

Available atEach tropic level(in kilocalories)

Productivity of Producers: The Rate Is Crucial

Productivity of Producers: The Rate Is Crucial

Gross primary production (GPP) Rate at which

an ecosystem’s producers convert solar energy into chemical energy as biomass.

Gross primary production (GPP) Rate at which

an ecosystem’s producers convert solar energy into chemical energy as biomass.

Figure 3-20

Fig. 3-20, p. 66

Gross primary productivity(grams of carbon per square meter)

Net Primary Production (NPP)Net Primary Production (NPP)NPP = GPP – R

Rate at which producers use photosynthesis to store energy minus the rate at which they use some of this energy through respiration (R).

NPP = GPP – RRate at which

producers use photosynthesis to store energy minus the rate at which they use some of this energy through respiration (R).

Figure 3-21

Fig. 3-21, p. 66Photosynthesis

Sun

Net primary production (energy available to consumers)

Growth and reproduction

RespirationEnergy lost and unavailable to consumers

Gross primary production

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Energy Flow. ENERGY Energy is the ability to do work and transfer heat. Kinetic energy – energy in motion heat, electromagnetic radiation Potential