1. All life functions are driven by chemical reactions.
Biochemistry
All life functions are driven by chemical reactions.
Why do we need to know chemistry in biology?

2. A. Levels of Organization
I. Introduction
A. Levels of Organization
Organism
Organ System
Organ
Tissue
(group of similar cells)
Cell
Organelle
Molecule
Atom

3. B. Elements Substance made up of only one type of atom
Most of living matter is made of C, H, O, and N
Familiarize yourself with:
C, H, O, N, S, P, Mg, Ca, Na, Cl, K, I, Al, Fe

5. C. The Atom
1. smallest unit of matter that retains the properties of an element
2. Subatomic Parts:
Charge
Mass
Location
Protons
Neutron
Electrons
Atomic nucleus
1.7 x g ≈ 1 dalton
Atomic nucleus
1.7 x g ≈ 1 dalton
1/1840 dalton
Orbitals

6. Proton _ _ _ _ _ _ + + + _ _ _
Neutron
Electron

7. 3.Atoms of different elements differ in their number of subatomic particles
a) Atomic Number = the number of protons (and # of electrons)
 protons and electrons are equal to maintain a neutral charge
b) Mass Number = sum of protons + neutrons
*Used as an approximation of atomic weight

8. Mass Number
Atomic Number
# Protons + Neutrons = 9
# Protons =
# Electrons = 4 4

9. *To calculate # of neutrons:
Subtract Atomic # from the Mass # 9
- 4
Atomic Number
Mass Number
# Protons + Neutrons =
# Protons =
# Electrons = 4 9 4 5
# of neutrons

10. atomic number
# protons =
# electrons =
# neutrons = 2 2 2
mass number / atomic weight

12. c) Isotopes
Atoms of the same element with the same number of protons but a different number of neutrons

13. (Place 1 electron per orbital before doubling up)
4. Electron Orbitals
3-D space in which electrons move around the nucleus
Maximum of 2 electrons per orbital
b) Orbitals are organized into energy shells that surround the atomic nucleus.
*First Shell = 1 orbital = max 2 electrons
**Each Shell After = 4 orbitals =max 8 electrons
(Place 1 electron per orbital before doubling up)
c) Valence Electrons: found in the outermost shell

15. 5. Bohr Diagrams
2nd Shell (and higher)
4 Orbitals
1st Shell
1 Orbital

16. 11 electrons total
1 valence electron

17. How many valence electrons?4

18. Carbon:
Oxygen:

19. 6. Lewis Structure (dot diagram)
Only shows atomic symbol and valence electrons
*Use periodic table column trick
Sodium:
Aluminum:
Nitrogen: Na Al N
Carbon:
Oxygen: C O