Chemistry for Biology

1
Chapter 2

• Chemistry for Biology

2
Getting to the Chemicals
3
Elements Can Not Be Broken Down to Another
Substance
Elements combined form compounds Sodium
chloride Water DNA
Humans
4
Atoms the smallest unit of matter that keeps the
properties of the element
Helium
Atomic 2 Mass Number 4
5
Isotopes changes in the number of Neutrons
6
Electron Arrangement
7
Chemical Bonds Ionic
Borrowing valuable electrons
8
Chemical Bonds CovalentSharing Valuable
Electrons
9
Chemical Reactions
10
Water it rules the world
Oxygen holds electrons more tightly than hydrogen
does . Therefore the oxygen part of water is
slightly negative, resulting in hydrogen bonds
11
Properties Cohesion
Water molecules stick together by hydrogen
bonds. Therefore they cohere and can be drawn
up a plant stem as water evaporates through the
leaves
12
Properties Evaporative Cooling
13
Properties Density
Water molecules in ice are farther apart than in
liquid water.. Therefore, ice floats in water
14
Properties The Universal Solvent
15
pH Acids and Bases
16
Acidification
Acid Rain
17
Summary

• Life down to the chemical level
• Matter elements and compounds
• Atoms
• Chemical Bonding and Molecules
• Chemical Reactions
• Water structure, properties, acidity