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Chapters 1, 3, 8 & 9
Big Idea: Why am I Big & Full of
Energy?
Or
Why am I made of my grandma’s
feces?
What is Biology?
Biology – the study of
life
Involves many aspects:
ecology, cellular
biology, biochemistry,
molecular biology,
genetics, evolution,
zoology, botany, etc.
Francesco Redi Spontaneous generation – the idea, accepted
for centuries, that life appears
spontaneously
Redi, an Italian scientist, did an experiment
to try and disprove this
John Needham
English scientist who did an experiment
to dispute Redi’s results
Lazzaro Spallanzani
Assumed that
Needham didn’t
heat his broth
enough to kill
microbes
Louis Pasteur
French scientist
who finally
disproved idea of
spontaneous
generation (150
years after Redi)
Characteristics of Living Things
1. Cell or cells that function together
2. Based on a Universal Genetic
Code
Contain DNA or RNA
3. Reproduction
The production of offspring is not essential
to an individual organism, but for the
continuation of a species
Can be sexual or asexual
4. Grow and Develop
Growth results in an
increase in the amount of
living material and the
formation of new
structures
Development is all of the
changes that take place
during the life of an
organism
5. Respond to Environment Environment – an organism’s surroundings, including
air, water, weather, temperature, and many other
factors
Stimulus – anything in an organism’s external or
internal environment that causes the organism to react
Response – reaction to a stimulus
6. Maintain a stable internal
environment
Homeostasis – regulation of an organism’s
internal environment to maintain conditions
suitable for survival
Done by using energy
7. Evolve
Evolution –the gradual change in a species through adaptations over time
Review
What is biology?
What are 4 characteristics of living things?
How are living things organized?
Which characteristic of living things is essential to a species, but not to an individual?
Give an example of a stimulus and response in nature?
What is homeostasis?
What is evolution?
What is Ecology?
Ecology – the
scientific study of
interactions among
organisms and their
environments. Reveals relationships
among living and
nonliving parts of the
world
Levels of Organization in Ecology Organism - anything that possesses all
the characteristics of life
Population – a group of organisms of one species that interbreed and live in the same place at the same time
Ex: All the bass in Utah Lake, the elk near Hardware Ranch
They may compete for resources, mates, etc. if there are limitations
Community – a collection of interacting populations
Ex: everything alive in Utah Lake or near Hardware Ranch
Communities may also compete for resources, or may even be dependent on each other for food, needed gasses, etc.
Levels of Organization in Ecology
Ecosystem – made up of the interactions among the populations in a community and the community’s physical surroundings, or abiotic factors
Three Kinds: terrestrial, freshwater aquatic, saltwater aquatic (marine)
Biome – similar ecosystems that share a similar ecosystem
Biosphere – the portion of Earth that supports life
Coral Reefs are a rich,
diverse and productive
ecosystems
A coastal wetland on Lake
Superior, Wisconsin.
Photo by K. Rodriquez
Review
What is ecology?
List the 5 levels of study in ecology (in order)
Explain population in ecology and give an example.
Explain community in ecology and give an example.
Explain ecosystem in ecology and give an example.
How Organisms Obtain Energy
All energy originates from
the sun
Autotrophs – organisms
that use the energy from
the sun (photoautotrophs)
or energy stored in
chemical compounds
(chemoautotrophs) to
manufacture their own
nutrients
Heterotrophs Organisms that cannot make their
own food and must feed on other organisms
Herbivores – feed on autotrophs
Carnivores – eat other heterotrophs
Omnivores – feed on both autotrophs and other heterotrophs
Scavengers – eat animals that have already died
Decomposers – break down and absorb nutrients from dead organisms (not eating, absorbing)
Food Chains Matter & energy flow
through organisms in
ecosystems (law of
conservation of energy)
Food Chain – a simple
model that shows how
matter and energy move
through an ecosystem
(what eats what) Give me an example
There is less energy at each
successive step of the food chain
Food Web Expresses all the possible
feeding relationships at each trophic level in a community
More realistic than a food chain because organisms depend on more than one other species for food
As you draw a food web, the arrows represent the direction of energy flow
Pg. 51 of book
Trophic Levels
Each organism in a food chain represents a feeding step, or a trophic level, in the passage of energy and materials
1st trophic level – autotrophs
2nd trophic level - 1° heterotrophs Herbivores, omnivores, decomposers, scavengers
3rd trophic level - 2° heterotrophs Omnivores, carnivores, decomposers, scavengers
4th trophic level - 3° heterotrophs Omnivores, carnivores, decomposers, scavengers
Ecological Pyramid Shows how energy flows through an
ecosystem
10% Rule: only about 10% of all energy can
be passed from one trophic level to the next
Producers (1025 Joules)
2° Consumer (11 Joules)
3° Consumer (1 Joule)
Pyramid of Energy
1° Consumer (98 Joules)
Pg. 52
Review What is the difference between a photoautotroph
and a chemoautotroph?
What are the 5 types of heterotrophs?
Give an example of a food chain with at least 4 organisms.
What is the difference between a food chain and a food web?
What is a trophic level?
What is the 10% rule?
What shape are ecological pyramids?
You & the Web of Life
Assignment
Bottle Ecology
ATP - Life’s Energy
Adenosine triphosphate
ATP stores energy in the
bonds between adenosine
and three phosphates (which
are charged).
When a bond between
phosphates is broken,
energy is released
Stored by creating bond
Jan van Helmont
Planted a seedling
Measured the mass of soil
Five years later, measured
mass of soil and of tree –
soil mass was unchanged
Concluded that mass of
tree came from water
Joseph Priestly
Lit a candle, put a jar on it and fire went out
Lit a candle, put it under a jar along with a sprig of
mint and the flame continued for a few days
Concluded that there is something in the air
produced by plant - oxygen
Jan Ingenhousz
Showed Priestley’s
experiment only
worked when the
plant was exposed
to light
Photosynthesis
The process that uses the sun’s
energy to make simple sugars
These sugars are then converted into
complex carbohydrates
3 Things needed:
Water
Oxygen
Light
2 Things Produced
Sugar
Carbon Dioxide
6CO2 + 6H20 C6H12O6 + 6O2
The Chloroplast & Pigments
Membranes in chloroplast contain pigments –molecules that absorb specific wavelengths of sunlight
Chlorophyll is the most common pigment
Absorbs most wavelengths of light except green
Light-Dependent Reactions
Light excites (energizes) electrons in the membranes
This energy is used to form ATP from ADP (adenosine diphosphate), which will be used in the light independent reactions
Electrons then combine with some “stuff” to make something called NADPH, which will also be used in the light independent reactions
Why is Water Needed?
Chloroplasts constantly need new electrons
Plants split water to get molecules in a process known
as photolysis (2 electrons per water molecule)
Oxygen is released into the air through little holes in leaves
called stomata (who uses it?)
Light-Independent Reactions The Calvin cycle (Melvin Calvin) is a series of
reactions that use carbon dioxide to form sugars
Uses what was produced in light rxns & CO2 from
atmosphere (comes in through stomata)
To Summarize Light Dependent
Reactions make carbon
dioxide (which is
released), ATP and
NADPH (which store
energy and are used
next)
In the Calvin Cycle,
the energy in the ATP
and NADPH is used to
make glucose (which
plants use as food)
Section Review
Why do you see green when you look at a leaf?
Why do you see other colors in the fall?
What is produced in the light-dependent reactions?
How do the light-dependent reactions of photosynthesis relate to the Calvin Cycle?
What is the function of water in photosynthesis?
What is the end product of photosynthesis?
Is chlorophyll a reactant, product, or neither in photosynthesis?
Cellular Respiration
The process by which mitochondria break down food molecules to produce ATP.
Three stages:
Glycolysis
Citric acid cycle (Krebs cycle)
Electron transport chain
Glycolysis is anaerobic (no oxygen required)
The other two stages are aerobic
Glycolysis
Glycolysis is a series of chemical reactions
in the cytoplasm of a cell that break down
glucose in two
2 ATP are required
4 ATP are made
2 NADH are made
Citric Acid Cycle Also called the Krebs cycle
A series of chemical reactions similar to the Calvin
cycle
Each pyruvate (pyruvic acid) loses a carbon and
makes an ATP “on the way” to the Krebs Cycle
Products per turn of cycle (2 turns per glucose)
3 NADH
2 CO2 - then breathed out
1 FADH2
1 ATP - Usable energy
back
FADH2
FAD+
ATP Totals from Aerobic
Respiration
10 NADH molecules = 30 ATP Each NADH leads to 3 ATP
2 FADH2 molecules = 4 ATP Each FADH2 leads to 2 ATP
2 ATP during glycolysis 4 ATP are made, but 2 are used
2 ATP during citric acid cycle 1 per pyruvic acid
GRAND TOTAL = 38 ATP per glucose
Ms. Lowe’s Video
Ms. Lowe’s Video
To Summarize:
Glycolysis:
Breaks down glucose from food
A little ATP is made that can used now
Other energy storing molecules made to be
used later
Krebs Cycle
Use oxygen and CO2 make more high energy
molecules
Electron Transport Chain
Uses energy in those molecules to make ATP
Fermentation Anaerobic process
Follows glycolysis and provides a means to
continue producing ATP until oxygen is
available again
2 major types:
Lactic acid fermentation (lactic acid produced -
in animals, for instance)
Alcoholic fermentation (ethanol & carbon
dioxide produced - yeast)
8
Comparing Photosynthesis and
Cellular Respiration
Occurs in ALL living cellsOccurs only in the presence
of chlorophyll
Doesn’t require lightRequires light
Produces CO2 and H2OProduces sugars from PGAL
O2 taken inO2 given off
Energy of glucose releasedEnergy from sun stored in
glucose
Food broken downFood synthesized
Cellular RespirationPhotosynthesis
Ms. Lowe’s Video
Section Review
How much ATP is made in glycolysis? In aerobic respiration? In anaerobic?
How do alcoholic fermentation and lactic acid fermentation differ?
How is most of the ATP from aerobic respiration produced?
Why is lactic acid fermentation important to the cell when oxygen is scarce?
Who will build up more lactic acid, a jogger or a sprinter?
Cycles of Nature Law of Conservation of Matter
www.BioEdOnline.orgBioEd Online
Water Cycle
www.BioEdOnline.orgBioEd Online
Carbon Cycle
www.BioEdOnline.orgBioEd Online
Nitrogen Cycle
Review
Tell me about the water cycle.
Describe one “path” through the carbon
cycle.
How do we get nitrogen from the ground
and into us?
Why MIGHT you eat your mom’s feces
for lunch today?