Atoms, Molecules, & Polymers
Cells to Ecosystems
Hierarcy of Matter




Click on this image of Helium!

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Atoms

The Periodic Chart

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Life is made up almost entirely of six light elements (in order of importance):

C, H, O, N, P, S = 99%

trace elements: Fe, Mg, Ca, Na

elements apparently necessary for life but not understood: Se

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Molecules

Combinations of atoms held together by bonds to form molecules: H₂O, CH₂O

inorganic compounds

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Life is dependent on the molecules water & carbon dioxide (2 reactions) !

Photosynthesis

   H₂O + CO₂ => CH₂O + O₂ L C


Respiration

   H₂O + CO₂ <= CH₂O + O₂ K

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Organic compounds: building blocks, molecules of C, H, O
Polymers: complex molecules made up of the building blocks example

Building blocks	Polymers
Sugar	Starch
Fatty Acid	Fat
Amino Acid	Protein
Nucleic Acid	DNA RNA

organic molecules link

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In turn, the polymers make up parts of cells ^*

lipids	cell membranes	cells
amino acids	proteins	cells
DNA	chromosomes	cells



cells make up Tissues ^*
which make up Organs (hormones) ^*
which make up Organisms ^*

Levels of Organization

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Organisms make up Ecosystems

Ecosystems have structure (trophic levels)
cycle nutrients, transfer energy
• producers (plants - photosynthesis [light])
  • herbivores (plant eaters)
    • carnivores (herbivore eaters)
      • decomposers (bacteria +)

LINK: Understanding Lake Ecology
LINK: Ecosystem Description (NOAA)

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What is life? (6-7 Characteristics)
        E.T.: (1) Reproduction (2) Evolution

1. Cells organized structure and function: single-celled organisms, muscle cells
2. DNA RNA self-replication
3. Energy capture & transformation = Photosynthesis & Respiration
4. Maintenance of favorable internal conditions = Homeostasis
5. Reproduction
6. Evolution (Antibiotic resistance)