1. General Chemistry
Review for the biological sciences

2. Why Chemistry???????
Hey…this is Biology! Why do we need to know about chemistry??
All living things are made up of
Atoms
Molecules
Chemicals
We need to know how chemicals interact to be able to understand biology!

3. Chemical Elements Each element consists of unique atoms
Represented by symbols—H, Na, Au, etc.
A total of 118 named elements
(what are they?)
1-92 are naturally-occurring
93+ are synthetic

4. Chemical Elements 92 naturally occurring elements
About 25 are considered essential to life
4 make up > 95% of living matter
Carbon
Hydrogen
Oxygen
Nitrogen

5. Chemical Elements Other significant elements
Ca—nerve impulse transmission, muscle action, blood clotting and cell permeability
P—in DNA & RNA, building bones & teeth, energy transfer & storage
K—fluid & electrolyte balance, normalizes heartbeat
S—a key component in most proteins

6. Chemical Elements Other significant elements
Na—flow of water in cells, blood, nerves
Cl—electrolytes, nerves, digestion
Mg—breakage of glucose and fat molecules, production of enzymes, proteins and regulation of cholesterol

7. Chemical Elements Trace elements
Fe—blood & oxygen transfer, protein metabolism, and energy production
I—thyroid hormones, growth/development
Cu—maintaining the strength of the skin, blood vessels, epithelial and connective tissue
Zn—absorption of Ca, growth, immune system
Co—function of red blood cells and nervous system

8. Atoms
The smallest particle of an element that has the qualities of that element
Made up of smaller sub-atomic particles
Cannot be broken down into simpler substances by ordinary means

9. Sub-atomic particles Neutrons nucleus Electrons Protons + +
neutral (no) charge
symbol n0
mass = 1+ amu + +
nucleus
Electrons
negative charge
symbol e-
located in electron cloud
Mass = 1/1840th amu
Protons
positive charge
symbol p+
mass = 1 amu

10. The atom (He)
The attractions between the positive charges in the nucleus and the negative charges of the electrons keep the electrons in the vicinity of the nucleus.

11. molecules Atoms of two or more different types chemically combined
Chemically different than the atoms that make them up
Molecules combine to form compounds

12. a water molecule H2O Hydrogen: a colorless, odorless gas; explosive!
water: a colorless, odorless liquid (at ordinary temps); necessary for life
H2O
Hydrogen: a colorless, odorless gas; explosive!
oxygen: a colorless, odorless gas; supports combustion

13. So…how are atoms held together in a molecule?
CHEMICAL BONDS!
Ionic: the giving and taking of electrons
Covalent: the sharing of electrons
Hydrogen: the attraction of + and -

14. Ionic Bonds Exchange of electrons Forms charged particles called ions
One atom takes electrons & the other donates them
Forms charged particles called ions
ex—sodium chloride

15. Covalent Bonds Sharing of electrons Between nonmetals Cl + Cl CH4
Non-polar
Polar

16. Covalent Bonds non-polar polar
Equal sharing of electrons between two or more atoms
Carbon, Hydrogen
CH4
C2H6
Unequal sharing of electrons between atoms
Forms polar molecules
Water, sugar, alcohol

17. Hydrogen bonds
The attraction between the +charged portion of one polar molecule and the –charged portion of another molecule
Found in water, proteins, DNA

18. Carbon and Macromolecules
Moving on to the chemistry of living things…
Carbon and Macromolecules

20. Carbon is the backbone Carbon has 4 valence electrons =Versatility
Chains (straight or branched)
Rings
Single, double and triple bonds
Isomers

21. Functional Groups
Certain groups of atoms that may be attached to a carbon skeleton and give organic compounds distinctive features.
Attachments that replace one or more of the hydrogens bonded to the carbon skeleton

23. Biomolecules or Macromolecules
Polymers produced by living things
Polymers are
Large molecules
made up of smaller, repeating units called monomers

24. Monomer + monomer + monomer + ….. creates the polymer
Condensation reaction/dehydration synthesis/ polymerization

25. Reverse reaction is hydrolysis

26. Polymer Carbohydrates Lipids Proteins Nucleic acids monomers examples
Starches, cellulose,
Pasta, potatoes, etc.
Fats, oils, waxes
Meat, muscle tissue, enzymes, hair, etc.
DNA & RNA
Simple sugars
Glycerol & fatty acids
Amino acids
nucleotides
Carbohydrates
Lipids
Proteins
Nucleic acids

27. THE END