Download Biome

CHAPTER 52 INTRODUCTION
.
Ecology Overview



Ecology is going to have a STRONG emphasis on
how systems interact.
You do not have to memorize any biomes in
particular, but you must make connections from the
molecular level (macromolecules) to entire biomes
Ex: How can a change in pH in soil have an impact
on an ecosystem.
 How
is free energy measured?
Overview: Energy TRANSFER
•
Cells
•

miniature chemical factories where thousands of reactions
occur
 extract energy and uses it for work
Some organisms convert energy to light
•
Bioluminescence (fungus, squid)
Metabolism: transforms matter & energy,


metabolism: total of all the chemical reactions in an
organism’s body
metabolic pathways begin with one molecule and ends
with a product
•
each step catalyzed by specific enzyme
Enzyme 1
A
Enzyme 2
B
Reaction 1
Starting
molecule
Enzyme 3
C
Reaction 2
D
Reaction 3
Product
The First Law of Thermodynamics

energy of the universe is
constant
•
•
conservation of energy
energy can be
transferred &
transformed, but not
created or destroyed
Chemical
energy
The Second Law of Thermodynamics

in transformation, some energy is unusable, and is often
lost as heat
•
energy transfer or transformation increases entropy
(disorder) of the universe
Heat


evolution of more complex organisms does not violate
the second law of thermodynamics
entropy (disorder) may decrease in an organism, but
the universe’s total entropy increases
Free Energy: ΔG = ΔH- TΔS
Free energy = enthalpy (total energy) change - temperature x entropy change
- ΔG: spontaneous
• exergonic: cell respiration
+ ΔG: energy needed
• endergonic: photosynthesis
ΔG = ΔGfinal – ΔGinitial
• If negative ΔG, spontaneous
since less free energy exists in
the products!
reaching equilibrium means death, no work
being done
REVIEW
Light energy


Sunlight - ultimate energy
source
ECOSYSTEM
Photosynthesis converts
sunlight to glucose in
chloroplasts; autotrophs
CO + H O
Cellular Respiration
converts glucose to ATP in
the mitochondria;
autotrophs & heterotrophs
2

Photosynthesis
in chloroplasts
2
Cellular respiration
in mitochondria
ATP
powers most cellular work
Heat
energy
Organic
molecules
+ O2
Electrons carried
via NADH and
FADH2
Electrons
carried
via NADH
Glycolysis
Glucose
Pyruvate
CYTOSOL
Pyruvate
oxidation
Acetyl CoA
Citric
acid
cycle
Oxidative
phosphorylation:
electron transport
and
chemiosmosis
MITOCHONDRION
ATP
ATP
ATP
Substrate-level
phosphorylation
Substrate-level
phosphorylation
Oxidative
phosphorylation
Cell Respiration Overview
C6H12O6 + 6O2  6CO2 + 6H2O + ATP
Cytosol
Mitochondrial matrix
Inner Mitochondrial Membrane
2 ATP
2 ATP
32 ATP
Chemiosmosis couples the electron transport chain to ATP synthesis
Chemiosmosis
Ubiquinone &
Cytochrome proteins
carry e- through ETC,
while proton pumps
pump H+ from matrix to
intermembrane space
+
 H ions create gradient
+
 H ions pass back
through the enzyme ATP
synthase into matrix and
ATP is made

ETC animation
Fate of pyruvate determined by O2
Glucose
CYTOSOL
O2 present:
• Pyruvate enters aerobic pathway:
Kreb’s, ETC
Pyruvate
No O2 present
Fermentation
O2 present
Cellular respiration
O2 absent:
• Pyruvate enters anaerobic
pathway: alcohol fermentation or
lactic acid fermentation
MITOCHONDRION
Ethanol
or
lactate
Acetyl CoA
Citric
acid
cycle
Aerobic respiration, Anaerobic respiration, Fermentation
Anaerobic Respiration
Aerobic Respiration
O2
 Mitochondria
 e acceptor is O2
 ~36-38 ATP (depends on
amount of O2 available to
the cell)





No O2
Cytosol
ETC has alternative e- acceptors
ATP production variable
Fermentation
•
•
•
•
No O2
Cytosol
e- acceptors are ethanol or lactate
2 ATP
PHOTOSYNTHESIS:
1. Chloroplast structure

Leaf
Mesophyll
Mesophyll cells
 Stomata – pores in leaf






Granum (Grana) Stacks of
thylakoids
Stroma – fluid filled space
Lumen – Inside thylakoids
Thylakoid – individual
membranes w/ folds for
increased surface area
Chlorophyll – pigment that
reflects green light
Chloroplast
5 µm
Outer
membrane
Thylakoid
Stroma
Granum
Intermembrane
space
Thylakoid
space
Inner
membrane
1 µm
2. Pigments in leaves


Chlorophyll a – primary
pigment absorbs violet,
blue and red
Accessory Pigments –
assist chlorophyll a in
capturing light energy
Chlorophyll b – absorbs
blue and orange
 Carotenoids – absorbs
blues

3. Photosynthesis Overview




Light energy  chemical
energy for food
6 CO2 + 6 H2O + Light Energy
 C6H12O6 + 6 O2
2 steps
1. Light Reactions



Occurs in Thylakoid membrane
photo
2. Calvin Cycle – Light
independent reaction or dark
reactions


Occurs in the stroma
synthesis
H2O
CO2
Light
NADP 
ADP
+ P
CALVIN
CYCLE
LIGHT REACTIONS
ATP
NADPH
Chloroplast
Figure 10.5
O2
[CH2O]
(sugar)
Light Reactions
Light Reactions
3. Water is split into oxygen
 Water
is used to supply the electrons that were
previously passed on in the electron transport chain.
Chemiosmosis: The process in which energy stored in
the form of a hydrogen ion gradient across a
membrane is used to do cellular work.
Calvin Cycle – Light independent
reactions
Occurs in the Stroma
1. Carbon from CO2 is used
through a series of
reactions to create G3P

A sugar molecule used to
create glucose
2. Uses ATP and NADPH to
make sugar.
Alternative Pathways




Hot dry climates
Conserve H2O
Problem – closing stomata
(stoma) to conserve water
loss also cuts off CO2
which limits sugar
production
Sends the plant into
photorespiration
C4 Plants




Sugar cane, corn, and
some grasses
Contains another
enzyme in addition to
rubisco- ONLY binds
CO2 (not O2) making
photosynthesis more
efficient.
Bundle sheath cells
Minimizes
photorespiration
C4 vs. CAM Plants
Pineapple
Sugarcane
C4
Mesophyll Cell
Organic acid
Bundlesheath
cell
(a) Spatial separation
of steps. In C4
plants, carbon fixation
and the Calvin cycle
occur in different
types of cells.
CALVIN
CYCLE
Sugar
CAM
CO2
CO2
1 CO2 incorporated Organic acid
into four-carbon
organic acids
(carbon fixation)
2 Organic acids
release CO2 to
Calvin cycle
CALVIN
CYCLE
Sugar
Night
Day
(b) Temporal separation
of steps. In CAM
plants, carbon fixation
and the Calvin cycle
occur in the same cells
at different times.
ECOLOGY, CH 52: You Must Know



The role of abiotic factors in the formation of
biomes.
How biotic and abiotic factors affect the distribution
of biomes.
How changes in these factors may alter ecosystems
Ecology: study of the interactions between organisms
and the environment

The ecological study of species involves biotic and
abiotic influences.
 Biotic
= living (organisms: behaviors & interactions
between organisms)
 Abiotic = nonliving (temp, water, salinity, sunlight, soil)
Levels of Organization
 Biosphere
 Biome
 Ecosystem
 Community
 Population
 Organism
 BBECPO
Heirarchy






Organisms- one living individual
Population: group of individuals of same species
living in a particular geographic area
Community: group of populations of different
species in an area
Ecosystem: community of organisms + physical
factors
Biome: group of ecosystems that have the same
climate and similar dominant communities (rain
forest , etc.)
BECPO
BIOSPHERE

portion of planet in which all life exists
(includes land, water, atmosphere)
Extends from:
8 km above the
Earth’s surface to 11
km below the ocean’s
surface
BIOME
• the world’s ecosystems classified according
to dominant vegetation & rainfall
Biomes
Aquatic
• Marine
•
•
•
•
Intertidal zones
Oceanic Pelagic
Coral reefs
Marine benthic zone
• Freshwater
•
•
•
•
Lakes
Wetlands
Streams and rivers
Estuaries
Terrestrial
Tropical
Desert
Savanna
Chaparral
Grassland
Coniferous forest
(taiga)
• Broadleaf forest
(deciduous)
• Tundra (arctic)
•
•
•
•
•
•
ECOSYSTEM

All the organisms in a community plus abiotic
factors


ecosystems are transformers of energy
& processors of matter
Ecosystems are self-sustaining

what is needed?
 capture energy
 transfer energy
 cycle nutrients
COMMUNITY
• All the organisms that inhabit an area
POPULATION

individuals of the same species living in an area.

capable of interbreeding and producing fertile offspring)
Biogeographic Realms
Organism’s Habitat
habitat: place where an
organism lives
 dispersal: movement of
individuals from areas of
high population density (or
their area of origin)

•
disruption of existing
communities and ecosystems
usually occurs
Organism’s Tolerance
tolerance: range of
conditions an
organism can
withstand
 acclimation:
changing in response
to environmental
factors

Responses to Change in Biotic &
Abiotic Environment




Migration
Hibernation / Dormancy
Conformers: change with
the environments
Regulators: maintain
homeostasis regardless of
external environment
Organism’s Niche



Niche: organism’s role in the environment
• includes ALL biotic & abiotic factors an organism
needs or uses
fundamental niche: range or resources the organism
can potentially use
realized niche: resources the organism actually uses
• if niches overlap  competition for resources
• Natural Selection
Climate: long-term prevailing weather conditions in
a particular area


Climate = temperature + precipitation + sunlight +
wind
Climate patterns described on 2 scales:
macroclimate or microclimate.
 Macro:
at global, regional or local level
 Micro: small-scale environmental variation (eg. under a
log)


Climate change: some species may not survive
shifting ranges
Climate and elevation determine biomes
Global Climate Patterns:
Sunlight intensity
Global Climate Patterns:
Air Circulation & Precipitation Patterns
Global Climate Patterns:
Ocean Currents
Global Climate Patterns:
Mountains affect rainfall
What is the rain shadow effect?
Biomes: major types of ecosystems that occupy
very broad geographic regions
Climate and elevation determine biomes
Figure 34.12
Climograph: plot of temperature & precipitation in a
particular region
Tropical Rain Forest
Desert
Savanna
Chaparral
Temperate Grassland
Northern Coniferous Forest
Temperate Broadleaf Forest
Tundra
Lakes
Wetlands
Streams & Rivers
Estuaries
Intertidal Zones
Oceanic Pelagic Zone
(Open Water)
Coral Reefs
Marine Benthic Zone
In your notebook copy:

Biogeochemical Cycle Definition:

CHNOPS – Why is each needed? Be Specific!

C (4)

H (2)

O (2)

N (2)

P (3)

S (1)

Nutrients vs. Energy

Biosphere

Cycles – For Each Cycle

Reservoir (Stored)

Plants get it?

Animals get it?

Returned to Reservoir
ECOLOGY PROJECT



Get in groups of 4 (no more) and begin researching
biome.
YOU MUST by today have a biome selected
(specific name of area you’re studying) and have
questions answered for part 1
Use the pogil diagrams to aid in this process. For
example, if you’re researching a tundra, google
“nitrifying bacteria in tundra” to get bacteria name