1. Chapter 2: Introductory Chemistry
ANATOMY & PHYSIOLOGY
Chapter 2: Introductory Chemistry

2. Objectives Define ion, molecule, and compound.
Explain how chemical bonds form.
Describe what happens in a chemical reaction and explain why it is important to the human body.

3. Intro to Chemistry Ions, Molecules, and Compounds ions
if an atom either gives up or gains electrons, it becomes an ion
symbolized by writing its chemical symbol followed by pos.(+) or neg.(-)
list ions in the body and their important functions

4. Ions, Molecules, and Compounds
when two or more atoms share electrons
may consist of two or more atoms of the same element or two or more atoms of different elements
(give an example of each above) O2
H2O

5. Ions, Molecules, and Compounds
a molecule containing atoms of two or more different elements
most atoms in the body are joined into compounds
(give two examples)
H2O
NaCl

6. Ions, Molecules, and Compounds
free radical
an electrically charged ion or molecule having unpaired electron in its outermost shell
i.e.) superoxide; formed by the addition of an electron to an oxygen molecule
is unstable and destructive to nearby molecules

7. ??Questions?? Lesson 2 What can generate free radicals in our bodies?
Exposure to ultraviolet radiation, sunlight, x-rays

8. ??Questions?? Lesson 2
2. List disorders and diseases linked to oxygen-derived free radicals? Cancer, atherosclerosis, Alzheimer's, emphysema, diabetes, cataracts, macular degeneration, rheumatoid arthritis, increase deterioration with aging

9. ??Questions?? Lesson 2
3. What substances can help minimize damage from free radicals? Consuming antioxidants

10. ??Questions?? Lesson 2
4. What forms can be taken as dietary supplements of these? Selenium, beta-carotene, vitamins C & E

11. Intro to Chemistry Chemical bonds
forces that bind the atoms of molecules and compounds
valence shell
outermost energy level of an atom that contains electrons
determines bonding behavior of the atom

12. Chemical bonds octet rule (“Rule of 8’s”)
The chance that an atom will form a chemical bond with another atom depends on the number of electrons in its valence shell
atoms interact in such a way so they will have 8 electrons in their valence shell; they will interact or bond

13. Chemical bonds 3 Types of Bonds ionic bond
attraction between ions of opposite charges
bond formed when electrons are completely transferred from one atom to another
cation – positive charged ions; protons exceed electrons
anion – negative charged ions; electrons exceed protons

14. Types of bonds ionic bonds
ionic bonds are found mainly in teeth and bones; provides strength
others are dissolved in body fluids
electrolyte – a compound that separates into ions when dissolved in water and can conduct an electric current

15. Types of bonds covalent bonds
a bond involving the sharing of electrons of two atoms
neither of the combining atoms loses or gains electrons
the greater the number of electron pairs shared, the stronger the bond
two atoms share one, two , or three pairs of electrons

16. Types of bonds covalent bonds
the most common chemical bonds in the body; form most of body structures
do not break apart when the molecule is dissolved in water

17. Types of bonds covalent bonds
nonpolar covalent bonds: share electrons equally
polar covalent bonds: share unequally; one atom attracts stronger than the other

18. Types of bonds hydrogen bond
weak bond in which a hydrogen atom forms a bridge between two electron-hungry atoms
result from attraction of oppositely charged parts of molecules rather than sharing of electrons – as in covalent bonds

19. Types of bonds hydrogen bond
are weak; cannot bond atoms into molecules
provide important links i.e.) DNA

20. Intro to Chemistry Chemical reactions
occur when new bonds are formed and/or old bonds break between atoms

21. Chemical Reactions Types of chemical reactions synthesis reaction
larger molecules are formed from simpler ones; A + B  AB
anabolism

22. Chemical Reactions Types of chemical reactions decomposition reaction
complex substances are broken down into simpler ones; AB  A + B
catabolism

23. Chemical Reactions Types of chemical reactions exchange reaction
bonds are both made and broken
atoms become combined with different atoms
AB + C  AC + B ;
AB + CD  AD + CB

24. Chemical Reactions Factors that influence the rate of reactions
temperature
particle size
concentration
catalysts

26. ?Questions?
5. Identify the energy form in use in each of the following examples:
Chewing food.
Vision (two types) i.
ii.
mechanical energy
light energy
electrical energy (nerve impulse)

27. ?Questions?
Identify the energy form in use in each of the following examples:
Bending the fingers to make a fist.
Breaking the bonds of ATP molecules to energize your muscle cells to make that fist.
mechanical energy
chemical energy

28. ??Questions?? 6. Define molecule.
A molecule is a combination of two or more atoms held together by chemical bonds.

29. ??Questions?? 7. Explain the basis of ionic bonding.
Ionic bonds form when electrons are transferred from one atom to another.

30. ??Questions?? 8. How do ionic bonds differ from covalent bonds?
In covalent bonds, electrons are shared among the atoms of the molecule; in ionic bonds, electrons are transferred.

31. ??Questions?? 9. What are the hydrogen bonds, and how
are they important to the body?
Hydrogen bonds are fragile bonds formed when hydrogen atoms bonded to one molecule (or one part of a single molecule) are attracted by electron-hungry atoms of other molecules (or other atoms of the same molecule).

32. ??Questions?? 10. The two oxygen atoms forming
molecules of oxygen gas that you breathe are joined by a polar covalent bond. Explain why this statement is true or false.
A polar molecule is formed only when the atoms of the molecule are different and have different electron-attracting abilities. Oxygen gas contains two oxygen atoms and is therefore nonpolar.

33. ??Questions??
Identify each of the following reactions as a synthesis, decomposition, or exchange reaction:
2 Hg + O2  2 HgO
Fe CuSO4  FeSO4 + Cu 2+
HCl + NaOH  NaCl + H2O
HNO3  H+ + NO3-