Natural Systems that Sustain Life

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Natural Systems that Sustain Life

• Life, ecosystems, photosynthesis, food chains,
  food webs, biogeochemical cycles

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Life

• Life is the ability of a system to maintain
  itself in a highly organized state and to grow
  and multiply with the help of a continual flux of
  energy and matter supplied by the environment.

http//fig.cox.miami.edu/cmallery/255/255life/top
ic_properties.htm
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Cells

• The fundamental organizational unit of life is
  called a cell
• Consists of a highly organized collection of
  interacting molecules encased in a suitable
  membrane
• Central core of a cell contains hereditary DNA
  which contains the information to make the whole
  organism

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An Idealized Animal Cell
Hill/Feigl/Baum, General, Organic, and Biological
Chemistry, MacMillan, NY,1993,516
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An Idealized Plant Cell
Hill/Feigl/Baum, General, Organic, and Biological
Chemistry, MacMillan, NY,1993,516
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Components of Cells and their Functions
Chicos/Garin/Rouse, "Chemistry Its Role in
Society",Heath, MA, 1973, 227
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Summary of the Characteristics of a Living
Organism
1. Living organisms all have a complex and highly
organized internal structure that they are able
to maintain throughout their lives.
2. To maintain their complex organization, living
organisms must be able to extract and transform
matter and energy from their environment. Metaboli
sm is the ingesting of certain materials (foods)
subjecting them to chemical reactions involving
the release of energy, and secreting some of the
products of the reactions. Plants get energy from
sunlight while animals obtain their energy from
the food they eat and digest.
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3. Living organisms respond to their surrounding
environment. To be able to maintain the chemical
reactions that keep the organism alive, the human
has the ability to maintain a relatively constant
internal environment (homeostasis) even when
external conditions (such as temperature) change
dramatically
4. A living organism is capable of growth by
using energy and raw materials from the
environment to increase in size, and to change as
it grows.
5. Living organisms are capable of reproduction -
producing offsprings that have attributes similar
to the parents.
Bloomfield, M.M., Stephens, L.J., Chemistry and
the Living Organism, 6th ed, NY, Wiley, 1996, pp
1-2. Miller, G.T., Jr., Energetics, Kinetics,
and Life An ecological Approach, Belmont, CA,
Wadsworth Publishing Company, Inc., 1971, p 237.
Pauling, L., College Chemistry , 3rd, Freeman,
San Francisco, 1964, p. 722.
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Flux of Energy and Matter that Sustain Life
http//wine1.sb.fsu.edu/bch4053/Lecture01/Lecture0
1.htm
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Biosphere

• The biosphere (Mass 4.2 x 10 15 kg) is the thin
  zone where life exists on Earth
• About 95 of all life forms are found in the
  region from about 300 ft below sea level up to
  about 9,500 ft above sea level

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Four "Spheres"

Keenan et al, General College Chemistry, 5th,
Harper and Row, NY, 1957, 3
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Symbolic World
Represent-ation of the Four "Spheres" as
intersecting circles
Biosphere
Miller, Chemistry, Wadsworth, CA,1976, 231
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Components of Biosphere

• The biosphere is made up of ecosystems- groups of
  different living species (biotic matter) that are
  interacting with one another and with their
  non-living (abiotic) environment

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General Diagram of an Ecosystem
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Biotic Cycle Producers

• Producers- organisms that produce their own food
  plants make their food by using energy from the
  sun and inorganic chemicals to do photosynthesis
  and some bacteria can get energy from inorganic
  molecules without using the sun's energy and make
  their own food from these chemicals

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Photosynthesis
DH 680 kcal for the above reaction
http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookPS.html
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Source of Energy Required for Photosynthesis
http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookPS.html
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Catalyst for Photosynthesis
Mg2
http//www.emc.maricopa.edu/faculty/farabee/BIOBK/
BioBookPS.html
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Energies Utilized in Photosynthesis
http//scifun.chem.wisc.edu/chemweek/chlrphyl/chlr
phyl.html
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Biotic Cycle Consumers

• Consumers- organisms that cannot make their own
  food they must eat and digest other organisms in
  order to get energy
• There are four types of consumers herbivores
  (plants only), carnivores (animals only),
  omnivores (plants and animals), scavengers (dead
  matter)

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Food Chains and Webs

• Food chain- sequence of organisms, each of which
  is the source of food for the next in an
  ecosystem
• Trophic level - the feeding order in a food chain
• Food web - interconnected food chains in an
  ecosystem

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Model of a Food Chain
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 83
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Simplified Food Web
Miller, Chemistry, Wadsworth, CA,1976, 242
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Importance of Biodiversity

• Healthy ecosystems have high bio-diversity,
  contain many different species of animals and
  plants in one area
• Implies that are a number of alternative food
  sources in the food web making the ecosystem more
  able to survive the loss of a species

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Biotic Cycle Decomposers

• Decomposers- consume the dead organisms and their
  waste, thus recycling nutrients from organisms'
  bodies back to the environment
• Without decomposers, the producers would run out
  of nutrients

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Summary of Ecosystem
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 82
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Chemical Cycles

• Producers are provided each of the major elements
  vital to a living system (C, O, H, N, and P) by
  biogeochemical cycles in which the elements move
  in cycles from the living world (biotic) to the
  nonliving physical environment (abiotic) and back
  again

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One way flow of energy through the biosphere
causes cycling of crucial elements
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 75
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Water Cycle
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 90
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Distribution of Water on Earth
Nebel/Wright, Environmental Science, 7th,
Prentice Hall, NJ, 2000, 415
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Carbon-Oxygen Cycle
Cunningham/Saigo, Environmental Science,
6th,McGraw-Hilll, NY, 2001, 68
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Nitrogen Cycle
Miller, Living in Environment, 12th,
Brooks/Cole,CA, 2002, 94
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Phosphorous Cycle
Turk/Turk, Environmental Science, 4th,Saunders,
PA, 198878