Chapter 2: Chem-Is-Try
Elements and CompoundsChemical elements of life
Atoms and MoleculesAtomic structure and function
Bonding and chemical reactions
TOD: Methods box p.30
Fig 2.17 mimic molecules
TOD: Methods box p.30
Fig 2.17 mimic molecules
Elements and Life
• Define element:• Compound:• SPONCH CaK • ( ONCH 96% )• Trace elements (Fe, I) • anemia, goiter—iodized salt, sea
weed• Crops too—nitrogen, calcium
Atoms and Molecules
• Quick review: electrons, neutrons, protons, orbitals, nucleus
• Atomic number• Atomic mass (mass number)• Dalton
HeliumHelium
Electron orbitals
1s 2s 2p (x, y, z)
The major elements of life
Covalent bonds Fig 2.10 (share electrons)
Polar Covalent Fig 2.11Bonds
* electronegativity
Ionic bonds (electron transfer +/- ions)
Hydrogen Bonds fig 2.14
Structure / Function Examples
Mimic molecules
T.O.D: Radioactive Tracers in Bio.
• Label chemical substances within cells, are traceable
• Scientists can locate substances within an organism &/or follow metabolic processes.
Sources
• Campbell, Reece, Mitchell. Biology, 5th Ed. 1999, Chap-ter one. Pgs. 1-21.
• Campbell, Reece, Mitchell. Biology, 5th Ed. 1999, Presentations CD-ROM.
• Click art CD-ROM, Broderbund.
VIDEOS on the instructor’s disk
Molecular shape
Structure / Function
Examples
Fig 2.7 Energy Levels of
Electrons
• light• fluorescence
• photo-synthesis
Energy Absorbed
Energy Lost
Hierarchy of life
