Chemistry Notes

BIOL 2010, Anatomy and Physiology I

Outline of Notes: Chapter 2: The Chemistry of Life, VAP

Preview: This is not a chemistry course, but your understanding of A&P requires some background knowledge of chemistry. The chemical level of organization sets the stage for everything that follows.

Part 1: Basic Chemistry Concepts

I. Atoms, Molecules and Bonds (Modules 2.1-2.5)

A. Chemistry: The Study of Matter

Matter: has mass and occupies space

3 States of Matter: Solid, Liquid and Gas

B. Atoms and Elements

1. Atomic Structure:

-Nucleus -Protons (p+), positively charged

-Neutrons (no), neutral, no charge

-Electron Cloud- mostly empty space with scattered e-

-Electrons (e-), negatively charged

-Electron shell = energy level

2. Elements = types of matter -each has its own symbol (1 or 2 letters)

-each has its own atomic number (# of p+)

13 most common elements in human body: CHOPKINS Ca Fe Mg Na Cl

(see table 2-1)

3. Isotopes-same element, different mass (diff # of no)

Most isotopes are stable, unstable isotopes are radioactive (radioisotopes)

Radiation is easily detected and is useful for diagnosis and imaging.

* B. Chemical Bonds –methods of obtaining stable electron shells

* -Electron Shells typically are more stable with 8 electrons (octet rule)

* -Two major types of bonds between atoms:

1. Ionic- loss/gain of e- to form charged particles (ions), Ionic Crystals

2. Covalent-sharing of electrons, atoms held together tightly (molecules)

* Polar/Nonpolar- e- are not always shared equally

* -unequal sharing leads to polarity (water, sugar, etc)=Hydrophilic

* -equal sharing/symmetry leads to non-polar (oils, fats)=Hydrophobic

* Note: ions are attracted to polar, but not nonpolar compounds (p.32 & p.39)

* 3. Hydrogen bonds are weak attractions between certain polar compounds

* Water, sugars, alcohols, proteins, nucleic acids...