Download 1. Atoms & Molecules

Chapter 2: Biochemistry
Part 1: Review of
Atoms &
Molecules
1. Atoms & Molecules
Atomic structure
Protons: (+) charge
Neutrons: No charge
Electrons: (-) charge
1. Atoms & Molecules
Element: pure substance that consist entirely of
one atom.
1. Atoms & Molecules
CHON- most common
elements in organisms.
-Carbon
-Hydrogen
-Oxygen
-Nitrogen
1. Atoms & Molecules
Molecules = bonded atoms
Chemical reactions: when molecules are
formed or broken.
E.
Metabolism= sum of all chemical reactions
in the body necessary to support life
(remember homeostasis?)
Mixture= molecules together with no change in
their physical properties (ex. sand + sugar)
Solution= one substance dissolved in another
(ex. Kool Aid)
i. pH
A.
B.
C.
D.
acid vs. base
7 is neutral, water
Below 7 = ACID
Above 7 = BASE
2. H2O and Diffusion
A.
B.
Water is crucial to life. 70-95% of all
organisms.
Water is a polar molecule (unequal
charges)
_
+
+
C.
D.
Molecules want to move from an area of
HIGH concentration to an area of LOW
concentration. This is DIFFUSION.
Rate of diffusion is affected by
1.
2.
3.
E.
Concentration
Temperature
Pressure
Final result is DYNAMIC EQUILIBRIUM.
F. Biological examples of diffusion
1.
2.
3.
4.
5.
Nutrients enter blood in the intestines
O2 enters blood in the lungs
CO2 leaves blood in the lungs
Materials move in & out of cells
H2O moves into plant roots