Warm Up List the levels of organization. (already covered) Why do you need an understanding of chemistry to understand biology.

Life is a series of chemical processes. The Chemistry of Life Life is a series of chemical processes.

The Nature of Matter Parts of the Atom atom - building blocks of matter subatomic particles within the nucleus protons + charge neutrons no charge around nucleus - cloud of – charged electrons

in most atoms, + and - are equal # of protons = # of electrons Neutral atoms do not have a charge.

if an atom gains or loses an electron an ion is formed loses electron → pos. ion gains electron → neg. ion

Elements are substances made of only 1 kind of atom. ex: carbon, oxygen The six most common elements found in living things are C, H, O, N, P, and S.

Elements are arranged in a periodic table by atomic # = # of protons Elements are arranged in a periodic table by atomic # = # of protons. This is unique to each element. ex: oxygen - 8, carbon – 6 Atomic mass is = to protons + neutrons. # of electrons = # of protons

Molecular formulas show the specific ratios of atoms in a compound. ex: H2O - made up of 2 hydrogen atoms and 1 oxygen atom Water H2O Carbon dioxide CO2 Oxygen O2 Glucose C6H12O6 Know these formulas.

Name the subatomic particles found in the nucleus of an atom and their charge. Where are electrons found? What makes an atom natural? How are ions formed? Why are they charged? List the most common elements found in living things. What does the atomic number represent? What does the atomic mass number represent? How do you determine the number of electrons in an atom? Write the molecular formula for glucose. What type of atoms does it have? How many of each? Review

Chemical Bonds In an attempt to fill their levels to become stable, atoms will interact with each other: covalent bonds share electrons

2. ionic bonds transfer electrons

What do these represent? 1. 2. 3.

Since carbon has 4 electrons in its outer level it can share an electron with 4 other atoms. This makes it easier to “build” large molecules that have a “backbone” of C.

C – C – C – C – C – C – - C – C – C – C – C – C – C – C – C – C

For this reason carbon is found in all organic compounds For this reason carbon is found in all organic compounds. (macromolecules) When atoms form bonds, energy is stored in the bonds.

When atoms break bonds, energy is released.

Review Why do chemical bonds form between atoms? How are covalent bonds formed? How are ionic bonds formed? Use the periodic table in your book and draw a carbon atom. Color protons red, electrons blue, and neutrons black. Explain why carbon can form the backbone of hundreds of molecules. In chemistry, what does “organic” mean? What is a macromolecule? What happens when chemical bonds break? What happens when chemical bonds form? Review