ENERGY CONVERSIONSDo Now

A jelly donut contains about 1 x 106 J of energy.A gallon of gasoline contains about 1 x 108 J of energy.

How many jelly donuts would provide the same amount of energy as a 20 gallon tank of gasoline?`

ENERGY AND SOCIETY It is not a coincidence that large-scale human

slavery in the Western world ended around the same time fossil fuels were rapidly expanding.

A human doing physical work for 8-hours a day can produce about 5 x 105 J of useful work.

A gallon of gasoline produces about 2 x 106 J of useful energy when burned in an engine.

How many gallons of gasoline produce the same amount of work as 50 humans working all day?

SOLUTION (2 x 106 J) [gasoline] / (5 x 105 J) [human] =

4. 1 gallon of gasoline produces as much work as 4

humans working all day. 50 [humans] / 4 = 12 ½ Conclusion: the same amount of work can be

done by 50 laborers or about 13 gallons of gasoline.

TAKE-HOME MESSAGE The amount of energy produced by burning

fossil fuels is huge in comparison to human labor.

Example: You could not power a large TV by riding a bicycle… but coal can.

TROPH = EATINGFROM BIO II “MICROBIAL ECOLOGY”

Do Now:Make a list (on your notes handout) of the things EVERY organism needs to survive.

JUST 3 THINGS Water Energy Carbon

Different organisms get these materials in very different ways… but we all get them!

THE FIRST ORGANISMS The very first organisms that

arose on Earth were very simple in structure.

We call these simple cells prokaryotes.

There are millions of species of prokaryotes alive today, and science has described only 0.1-5% of them!

THEY’RE EVERYWHERE!!! This is from a soil

sample… about 2,000x magnification… notice how many different kinds are in such a small space.

SOME FAMOUS PROKARYOTES…

ESCHERICHIA COLI

STAPHYLOCOCCUS AUREUS

HELICOBACTER PYLORI

CYANOBACTER SP.

BACILLUS SUBTILIS

MICROBES ARE EVERYWHERE!Prokaryote: A unicellular organism that lacks a nucleus and all other membrane-bound organelles.

Microbe: An organism too small to be seen by the naked eye.

WAYS THEY SURVIVEProkaryotes may be heterotrophs or

autotrophs.Heterotroph: an organism that gets

carbon from organic molecules produced by other organisms. Heterotrophs are consumers.

Autotroph: an organism that uses an energy source (such as light) directly to build organic molecules from inorganic carbon source (usually CO2)

HETERO VS. AUTOHetero means “different”, and auto means “self”… does this make sense, since troph means “eat?”

Hetrotroph and Autotroph refer to how an organism gets carbon.

Mycobacterium tuberculosis causes tuberculosis. The cells feed on the lung cells of their hosts.

Heterotroph or autotroph?

Thyobacilus ferroxidans gets its energy from turning iron (II) oxide into iron (III) oxide. They use the energy they get to take CO2 from the

environment and build sugars and other compounds. Heterotroph or autotroph?

HOW DO YOU GET ENERGY? Energy is another critical thing all organisms

need access to. The prefix “photo” indicates an organism gets

energy from light. The prefix “chemo” indicates an organism gets

energy from a chemical.

Phototroph and chemotroph describe how an organism gets energy: from light, or from chemicals.

BURGER OR NAILS? Chemotrophs, which get their energy from

chemicals come in two flavors: Organotrophs (like you & I) who break down

organic chemicals they take in. Lithotrophs (litho = rock) who break down

inorganic substances

Only 4 ways to Survive on

Earth!

Get carbon from food to build molecules

Use inorganic carbon (CO2) to build molecules

Get energy directly (light)

Photoheterotroph Photoautotroph

Get energy from chemicals

Chemoheterotroph Chemoautotroph

DIATOMS ARE UNICELLULAR ALGAE THAT GET CARBON FROM CO2 IN WATER, AND ENERGY FROM LIGHT. WHAT ARE THEY?

Here’s another one

Some more varieties

How organisms get the energy to survive & reproduce

BIOENERGETICS:

2nd Law of Thermodynamics: In an isolated system, entropy (disorder)

increases So how do living things remain so organized,

and in fact increase the organization in and around themselves? ENERGY. Living things use energy to prevent

entropy from destroying them. Living things are “negative entropy machines”

ENTROPY

ENTROPY AND ENERGY

ORDER

Chaos

Energy Released(ΔG < 0)

Energy Required(ΔG > 0)

SpontaneousNonspontaneous

PHOTOSYNTHESIS & RESPIRATION

C6H12O6+ 6 o2

ATP Energy Produced

Light Energy Required

6 Co2 + 6 H2O

Photosynthesis

Respiration

ORDER VS. CHAOS

ATP Energy Produced

Light Energy Required

Photosynthesis

Respiration

Photosynthesis : the process by which plants and other photoautotrophs store the energy of light as chemical energy in carbohydrates.

(Cellular) Respiration: the process by which animals and other chemotrophic organisms transform chemical energy stored in carbohydrates (or other sources) into available energy (ATP).

CRITICAL DEFINITIONS

Make a connection: ΔG = ΔH – TΔS

Remember: Gibbs Free Energy always decreases in spontaneous reactions.

S = entropy. Note that big entropy increases (disorder) tend to make a chemical reaction spontaneous!

In other words, when ΔG is negative, reactions happen without the input of work.

Gibbs Free energy change when breaking down glucose = -2870 kJ/mol

CHEMISTRY II STUDENTS…

Reducing carbon (adding more H to it) requires energy (i.e. photosynthesis)

Oxidizing carbon (adding more O to it) releases energy (i.e. combustion)

REDOX REACTIONS

Photosynthesis RespirationRequires energy Releases energyCarbon is reduced

Carbon is oxidized

Entropy decreases (produces order)

Entropy increases (produces disorder)

Nonspontaneous SpontaneousPhototrophs Chemotrophs

BIOENERGETIC CHEMISTRY

Along with bioenergetics, we will also study the true

algae: unicellular Eukaryotic photoautotrophs.

ORGANISMS

CHLOROPHYTA: GREEN ALGAE

PHAEOPHYCEAE: BROWN ALGAE

RHODOPHYTA: RED ALGAE

HUMAN ECOLOGY & ENERGY USE

HUMAN ENERGY USE

CONSEQUENCES