Energy

Energy is defined as the ability to do work.

Work is causing a change that would not otherwise occur.

Energy FormsKinetic energy = energy of motion

Light energy = electromagnetic radiation energy that travels through space as waves

Potential energy = stored energy

Chemical energy = energy stored in molecules in the bonds between atoms

What are some other forms of energy?

Potential energycan be convertedinto kinetic energy

Kinetic energy can be converted into potential energy

First Law of EnergyThe First Law of Energy (or conservation

of energy principle) states that energy cannot be created or destroyed. Energy can only be converted from one form to another.

The Second Law of Energy states that when energy is converted from one form to another, some energy will be unusable, usually lost as heat.

Calories (kilocalories)= units of energy

ATPATP is the source of chemical energy for

cellular work.

ATP (adenosine triphosphate)

The ATP Cycle

This is really important !

Cellular Respiration

Cellular Respiration is the harvesting of chemical energy from organic fuel molecules (i.e. glucose) and converting that energy into the chemical energy in ATP molecules.

Aerobic cellular respiration

requires oxygen (O2)

Aerobic Cellular Respiration Net Chemical Equation

Can produce 38 ATP

from the energy in ONE Glucose

Aerobic Cellular Respiration

In your body cells;

Where does the Glucose come from?

Where does the Oxygen (O2) come from?

Where does the carbon dioxide (CO2) go?

Aerobic Cellular Respiration

If one glucose molecule contains 686 kcal

and

One ATP molecule contains 7.5 kcal

What is the energy efficiency of aerobic cellular respiration?

What has happened to the remaining energy?

Anaerobic Cellular Respiration harvests energy from food without oxygen.

Fermentation is the most common type of anaerobic cellular respiration.

Fermentation occurs in botheukaryotic and prokaryotic cells.

Anaerobic Cellular Respiration

Fermentation inHuman Muscle Cells

Fermentation in Yeast

CO2 produced by yeast fermentation makes the air bubbles in baked goods

Ethyl alcohol produced by yeast fermentationis in adult beverages

Fermentation in Microorganisms

Anaerobes are organisms that conduct anaerobic cellular respiration.

Facultative Anaerobes can conduct either aerobic or anaerobic cellular respiration.

Obligate Anaerobes can only conduct anaerobic, and are actually poisoned by oxygen.

PhotosynthesisPhotosynthesis is the process where

green plants (& some bacteria) convert

light energy into the chemical energy contained in glucose molecules.

Oxygen seeking bacteria migrate toward algaeexposed to certain colors of light.

Photoautotrophs = make own food molecules using light energy

Photoautotrophs can be unicellular eukaryotic organisms

Photoautotrophs can be prokaryotic organisms

Photosynthesis Net Chemical Equation

Light Energy

Glucose produced is used for;

• Cellular Respiration

• Starch (stored glucose)

• Cellulose (structural)

• Other Organic Compounds

Energy Flow

Sunlight Glucose ATP

Always ONE WAY Flow

Solar-Driven Evolution

Plants that use CO2 directly from the air are called C3 plants (CO2 binds to a three carbon molecule when it enters the plants cells)

Common crops like oats, wheat, soybeans and rice

C3 plants close their stomata on hot, dry days to reduce the loss of water, but this also prevents CO2 from entering the leaves. Why is this a problem?

Alternate modes of incorporating carbon from CO2 have evolved in some plants, allowing them to save water without shutting down photostnthesis.

C4 plants are named for the four-carbon molecule that CO2 binds with inside the cell.

This molecule then shuttles the CO2 to a nearby cell, which can keep on making sugars even if the stomata are closed on a hot, dry day.

Corn and sugarcane are examples

CAM plants have adapted to very dry climates by opening their stomata and admitting CO2 only at night.

CO2 binds a four-carbon molecule at night and releases the CO2 in the same cell for photosynthesis during the day.

Examples are pineapples, cacti, and succulents like aloe and jade.

Energy Flow is always ONE WAY thru Ecosystem

Food Chain = sequence of food transfers from producers thru several levels of consumers

Trophic Levels = eating levels in a food chain

• Quaternary Consumer• Tertiary Consumer• Secondary Consumer• Primary Consumer• Producer

Decomposers / DetritivoresDetritus = animal wastes, plant litter (detritus), and dead

organisms

Detritivores eat detritus, and by breaking it down into molecules that other organisms can use they recycle these nutrients.

Termites

Decomposers, mostly bacteria & fungi, are an important trophic level

Food Web = a network of interconnecting

food chains

Biomass

Biomass = the weight, or mass, of organic material in an ecosystem

Biomass can be determined for a trophic level, as well as whole ecosystem

Example; The weight of all the plants equals the biomass of the producers

Primary Productivity = the rate at which plants and other producers build biomass, or organic matter in an ecosystem

The primary productivity of the entire biosphere is about 170 billion tons of organic material per year

Primary Productivity varies with environmental conditions

Remember the Second Law of Energy states that when energy is converted from one form to another, some energy will be unusable, usually lost as heat.On average, only about 10% of the energy eaten at each trophic level is stored as biomass in the next trophic level

Energy Pyramids show the energy in all the organisms at each trophic level

Why would it be more efficient for humansto eat more plants and less animals?

Chemicals or Nutrients CYCLE thru an Ecosystem

Biogeochemical Cycles = any of the chemical circuits occurring in an ecosystem, involving both biotic and abiotic components of the ecosystem

Biogeochemical Cycles

BIOTIC(Community)

ABIOTIC(Physical Environment)

Examples of Biogeochemical Cycles

• Carbon Cycle

• Nitrogen Cycle

• Phosphorus Cycle

• Water (Hydrologic) Cycle

Carbon Cycle

The Greenhouse Effect

Greenhouse Effect = Warming of atmosphere

caused by greenhouse gases, like

CO2, CH4 and others that absorb heat

and slow its escape from the Earth’s surface.

Carbon Dioxide or CO2

is the principle greenhouse gas

The Greenhouse EffectCO2 and other greenhouse gases act like

clear glass in a greenhouse or your car.

Normally this is beneficial because it increases average temperatures by about 10oC (18oF) making the Earth livable.

The Industrial Revolution, which began about 1800, was the shift from an economy based on manual labor to one dominated by industry with steam powered machinery (fueled primarily by coal).

Steam-powered ships, railways, the internal combustion engine and electrical power generation were all developed by 1900 .

Fossil FuelsCoal Oil (gasoline) Natural Gas

Burning fossil fuels releases CO2 into the air

Since the Industrial Revolution

the amount of CO2 in the atmosphere

has increased about 30%,

mostly from burning fossil fuels.

Global WarmingAt the present rate of increase by 2075 the

amount of CO2 in the atmosphere will be double the amount at the start of the Industrial Revolution.

If CO2 does double by 2075 it is predicted

that the world’s average temperature

will increase by almost 4°F.

If it only rises 2°F it would be warmer than anytime in the last 100,000 years.

2005 0.6183 0.9593 0.4896

2010 0.6171 0.9642 0.4885

1998 0.5984 0.8320 0.5090

2003 0.5832 0.7735 0.5108

2002 0.5762 0.8318 0.4798

2006 0.5623 0.8158 0.4669

2009 0.5591 0.7595 0.4848

2007 0.5509 0.9852 0.3900

2004 0.5441 0.7115 0.4819

2001 0.5188 0.7207 0.4419

2008 0.4842 0.7801 0.3745

1997 0.4799 0.5583 0.4502

1999 0.4210 0.6759 0.3240

1995 0.4097 0.6533 0.3196

2000 0.3899 0.5174 0.3409

1990 0.3879 0.5479 0.3283

1991 0.3380 0.4087 0.3110

1988 0.3028 0.4192 0.2595

1987 0.2991 0.2959 0.3005

1994 0.2954 0.3604 0.2704

1983 0.2839 0.3715 0.2513

20 warmest years on record 1901–2000

What Will Happen?= Global Climate Change

Melting of Polar Ice (including Greenland)

will raise sea level by 100 meters,

which will flood coastal areas.

For example, Miami, New York, Los Angeles

will all be underwater.

Is it Possible?!Miami, FL 11 ft

New York, NY 87 ft

Los Angeles, CA

330 ft

New Orleans, LA

11 ft

Climate Change

Our major agricultural area,

the central part of the United States,

will become much drier.

Climate ChangeMost natural ecosystems will be affected

based on predictions from mathematical models.

Study of prehistoric periods of warming & cooling shows that the types and numbers of plants were

altered dramatically by climate changes.

Past climate changes were very gradual, so plants and animals could spread into areas where conditions

allowed them to survive.

The concern is that global climate change today is too rapid, so plants and animals may not be able to survive.

A Miracle?What if we had some living things on Earth

that would remove carbon dioxide

from the atmosphere?

What if we had lots of these organisms living all over the Earth?

We Do ! They are called PLANTS.

Plants use CO2 to make sugars

during the process of photosynthesis.

DeforestationDeforestation is the change of forest land to

non-forest land such as;Farmland

Cities

Logged areas

Wasteland

Deforestation = Cutting down trees

Less trees = Less Photosynthesis

DeforestationLess Photosynthesis means less CO2

being removed from the atmosphere.

Plus, the burning of trees after

deforestation to clear land in the tropics

adds about 20% of the total excess CO2

into the atmosphere.

The other 80% of excess CO2

is from burning fossil fuels.

What Can Be Done?Reduce deforestation, particularly in areas like the tropics, NW and SE United States, Canada and Siberia.

What Can Be Done?

Since fossil fuels power industry and

economic growth it will not be easy.

It will require strong individual commitment & acceptance of major lifestyle changes.

Developed countries with the most industry

need to take the greatest responsibility.

The U. S. consumes more energy

than the TOTAL populations of

Central America, South America,

Africa, India and China.

That is almost 4 billion people

versus only about 300 million

people in the U. S. !

Moderation of global climate change depends mainly on the richest countries

reducing their use of fossil fuels

by conserving energy and developing alternative energy sources

like wind, solar,

and geothermal.

Individually we must become

more energy-efficient at home

and reduce our reliance on the

automobile.