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