1. Standard
d. Explain the impact of water on life processes (i.e., osmosis, diffusion).

2. Before we get to the standard, you need to understand the basics of…..

3. BIOCHEMISTRY

4. Biochemistry is…. The Chemistry of Life
Cell (skin cell)
basic building block of living organisms (life)
Atom
basic building block of matter

5. Atom: the basic unit of matter Elements: simplest form of a substance
CHEMISTRY OF LIFE
Atom: the basic unit of matter
composed of protons, neutrons, and electrons
Elements: simplest form of a substance

6. Parts of an atom Subatomic particles: parts of an atom
Neutrons and Protons (+) are located in the nucleus of an atom.
Electrons (-) orbit around the nucleus

7. What is an Isotope? Iso means same
Atoms of the same element that HAVE A DIFFERENT NUMBER OF NEUTRONS   

8. ISOTOPES (iso- = same)
Some isotopes are radioactive. This means that their nuclei is unstable and will break down at a CONSTANT RATE over time.
There are several practical uses for radioactive isotopes:
CARBON DATING
TRACERS
KILL BACTERIA / CANCER CELLS

9. Quick check Fill in the blanks below as a class:
The smallest unit of matter is called an __________.
An atom is made up of protons, ____________ and _____________.
The simplest form of a substance is called an ____________.
If an isotope is radioactive, then the nucleus will ________________ over time.

10. So, what elements are essential for life?

11. These are!!! Carbon, Hydrogen, Oxygen, Phosphorous, Nitrogen, Sulfur

12. Um….. Question!
How do elements combine to make up everything on Earth!

13. Answer!
Through chemical bonding
This makes molecules and compound!

14. MOLECULES and COMPOUNDS
A molecule is formed when two or more atoms join together chemically.
A compound is a molecule that contains at least two different elements.
All compounds are molecules but not all molecules are compounds.
Ex: water, salt, glucose, carbon dioxide

16. CHEMICAL BONDS
Chemical bonds hold the atoms in a compound (aka molecule) together.
There are 2 types of chemical bonds IONIC and COVALENT

17. IONIC BONDS (think magnets)
Occur when 1 or more electrons are TRANSFERRED from one atom to another.
Loss of electron=positive.
Gain of electron=negative
These newly charged atoms are now called IONS
Example: Na+ ion bonds to a Cl- to make NaCl (salt)
THIS MAKES COMPOUNDS!

19. COVALENT BONDS Occur when electrons are SHARED by atoms.
**These new structures that result from covalent bonds are called MOLECULES
SHARING IS CARING!

20. Quick Check Are all molecules compounds? (yes or no)
The transfer of electrons is __________ bonding
The sharing of electrons is _____________ bonding

21. Now what is the deal with water? Why is it important for life?

22. Water is special! Water is made up of 2 hydrogens and 1 oxygen
The oxygen is negative and unequally shares the electrons from the hydrogen, thus making hydrogen positive

23. So what’s the big deal?
Because oxygen is “electronegative” it creates poles on the water molecule.
Makes it act like a magnet
This property is called POLARITY.

24. Hydrogen bonds
The bond formed between water molecules is called a hydrogen bond.
Hydrogen bonds are very weak bonds

25. Properties of water Water has 4 main properties Cohesion Adhesion
High specific heat
High heat of vaporization

26. Properties of water: Cohesion
Cohesion: attraction between particles of the same substance
This is why water sticks to itself
Creates surface tension

27. Properties of water: Adhesion
Adhesion: Attraction between two different substances
Allows water to stick to objects
Enables transpiration in plants

28. Properties of water: High Specific Heat
High specific heat: amount of heat needed to change a substance 1 degree Celsius
Water resists change
Water can absorb and release heat with little change in overall temperature

29. Properties of water: High heat of vaporization
Heat of vaporization: amount of energy needed to change a substance from a liquid to a gas
Hydrogen bonds must break
This breaking removes a lot of heat
Causes a global “blanket”; helps cool earth!!!! 