1. Chemistry of Life
Exploring Life Chapter 4
By M. Donohue

2. Chemistry in Biology???
-Biology isand all living things are made up of.MATTER!
The study of matter and the changes it under goesAre living things changing?
Chemistry
Anything that takes up space (V) and has mass (g)
Composed of one or more elements
Matter
Pure substance that cannot be broken down into other substances by chemical meansbasic ingredients of matter; examples gold, helium, oxygen, nitrogen
Element
Substance containing two OR MORE elements chemically combined in a fixed ratioexample: water, sodium chloride (aka table salt)
Compound
Smallest possible particle of an element; building block of matter
-derived from Greek word atomos which means indivisible
Atom
An alternate form of an element; same # of protons, different number of electrons
Isotope
3. Elements
Pure substances
About 25 essential elements to life
Trace elements
Make up less than 0.01% of body mass but are critical
-Over 10092 naturally occurring and the rest are synthetic/man-made
-made up of 1 type of atom
Iodine
Iron
4. 5. Some Terminology

Chemical Symbol

One, two or three letters that represent an element on the periodic table (H, Al, Uuu)
First letter always capitalized, second (and third) ALWAYS lowercase
Doesnt always have to be the first letter of the name (ex. Fe for Iron, K for Potassium)

Chemical Formula

Used to represent a COMPOUND (2 or more elements bonded together)
Subscripts indicate the # of atoms of the preceding element inthat compound
If there is no subscript, it is 1 atom
Ex. H2O, NaCl, C6H12O6

Chemical Equation

Representation of a chemical reaction
Reactantsgo in and products come out
2H2 + O2 2 H2O
H2CO3(aq) -> H2O(l) + CO2(g)
6. Physical Change/properties
Color, shape, texture, amount
The actual make-up of matter/substance does NOT change
Examples
Ripping a piece of paper
Painting a wall
When two substances are combined to create a new substance with new properties different from those that made it upCombo of different elements
Examples
Water H2O
Sodium chloride NaCl
Chemical change/properties
Compounds
When 2 or more elements are chemically combined in fixed ratios making a new substance with new properties
7. Atomic Theory
Daltons Atomic Theory
1) All matter is made of atoms that are indivisible and indestructible.
2) All atoms of a given element are identical in mass and properties
3) Compounds are formed by a combination of two or more different kinds of atoms.
4) A chemical reaction is a rearrangement of atoms.
8. Structure of an Atom
-smallest unit of matter that retains properties of element
-Atom has an electric charge of zero (all positives equal negatives)
9.

Atomic Number= Number of protons

10. You can find this on the periodic table 11. (smaller # by the elementgoes in numerical order) 12. In a neutral atom: (charge of 0)# of p+=# of e--

Mass Number = the number of protons and neutrons in the nucleus of an atom

13. (bigger # on PT) 14. # of neutrons= mass# - atomic#