1. The Chemistry of Life

2. In your notebooks:
Today’s date: August 28th, 2017
Title: Unit: The Chemistry of Life
With a partner, think about this question: Why is chemistry important in biology? Make a list of 3 ways chemistry affects living things and/or chemical processes living things perform.

3. The Chemistry of Life Big Idea: Matter and Energy
Essential question: What are the basic chemical principles that affect living things?
Guiding questions:
What is the matter in organisms made of?
Why are the properties of water important to organisms?
How do organisms use different types of carbon compounds?
How do chemicals combine and break apart inside living organisms?

4. Basic Chemistry Atoms are the basic unit of matter
Elements are pure substances which consist of entirely one type of atom
Molecules and compounds are formed when elements bond together
All things (living and nonliving) on Earth are composed of atoms, molecules, and compounds

5. Subatomic Particles: What makes up an atom
Subatomic Particles: What makes up an atom? Electrons, Protons, Neutrons
The number of protons (+) determines chemical behavior
The number of electrons (-) determines how it will react with other atoms
The number of neutrons (no charge) determines radioactivity (*isotopes)

6. Element, molecule, or compound?
Ca (calcium)
OH- (hydroxide ion)
O2 (oxygen)
H20 (water)
C6H12O6 (glucose)
Are these examples of living things?

7. Elements of Life Carbon Hydrogen Nitrogen Oxygen Phosphorus Sulfur
Chlorine Cl
Potassium K
Calcium
Sodium Na

8. Ions
When an atom gains or loses an electron it also gains a charge (+ if loses an electron) or (- if gains an electron)
When an atom or groups of atoms has a (+) or (-) charge it is called an ion
Our heartbeat, taste, and nervous systems all utilize ions to function

9. How do elements form the molecules and compounds of life?

10. Types of Bonding: Covalent Bonds
When two atoms share electrons equally
The electrons move around the nucleus of both atoms in the bond
Examples: H2 O2
H20

11. Types of Bonds: Ionic Bonds
Formed when electrons are transferred from one atom to another; one atom gains e- and one atoms loses e-

12. Bonding

13. Chemical Formulas The chemical formula of a substance indicates:
The elements in the molecule
The number of atoms of each element in the substance
Example: 6H2S04
2 atoms of the element hydrogen; 1 atom of the element sulfur; 4 atoms of the element oxygen
A number in front of substance indicates how many molecules of that substance there are:
There are 6 molecules of H2S04 in the example

14. Chemical Reactions
Are changes which result in the formation of one or more new substances
The starting materials are called the reactants (what is reacting)
The ending materials are called products (what is being produced)

15. Chemical Reactions
During chemical reaction bonds between molecules can be broken (not always) and new bonds are formed
Example: A + B  C
Bond between A and B forms new compound C
Example: AB + CD  AC + BD
Bond between A and B broken
Bond between C and D broken
Bond between A and C forms
Bond between B and D forms

16. Chemical Reactions

17. Chemical Equations
Identify the reactants and products of a chemical reaction
Gives the chemical formula of each substance involved in the reaction (the reactants and the products)
Looks like this:
X + Y  XY
AB + CD  AC + BD
Reactants on LEFT of arrow
Products on RIGHT of arrow

18. Essential to life processes Transport materials
Water
Essential to life processes
Transport materials
Molecules can dissolve in it and react

19. Polar Molecule
Sometimes when atoms form covalent bonds, they do not share electrons equally
There is an unequal distribution of charge (since electrons have a negative charge)
In other words, one side of the molecule is “positive” and the other side of the SAME molecule is “negative”

20. Polar Molecule – H20

21. Polar Molecule – H20
For a water molecule, the negative side is the Oxygen and the positive side in the Hydrogen (the “ears”)

22. There is NO “negative” or “positive” side
Non-Polar Molecule
A non-polar molecule is one that the electrons are distributed more equally
There is NO “negative” or “positive” side

23. Non-Polar Molecule – CO2