DO NOW: Write 2 Level Two Questions for Chemistry NTK

SEPTEMBER 17 PROPERTIES OF WATER DO NOW: Homework Check in Learning Target: Explain the properties of water that make life on Earth possible Lesson: Notes on Water Homework: Bozeman Video on water (see Link) and complete water and the fitness of the environment.

Acids, Bases and pH One water molecule in 550 million naturally dissociates into a Hydrogen Ion (H+) and a Hydroxide Ion (OH-) Hydrogen Ion Hydroxide Ion Acid Base Acid Base H 2 O  H + + OH -

The pH Scale concentration of H + ionsIndicates the concentration of H + ions 0 – 14Ranges from 0 – 14 7 is neutralpH of 7 is neutral 0 up to 7 is acidpH 0 up to 7 is acid … H + above 7 – 14 is bpH above 7 – 14 is basic… OH - 10XEach pH unit represents a factor of 10X change in concentration pH 3 is 10 x 10 x 10 (1000) stronger than a pH of 6pH 3 is 10 x 10 x 10 (1000) stronger than a pH of 6

Acids Strong Acids have a pH of 1-3Strong Acids have a pH of 1-3 Produce lots of H + ionsProduce lots of H + ions

Bases Strong Bases 11 to 14Strong Bases have a pH of 11 to 14 lots of OH - ionsContain lots of OH - ions and fewer H+ ions

Buffers Weak acids or bases that react with strong acids or bases to prevent sharp, sudden changes in pH (neutralization).Weak acids or bases that react with strong acids or bases to prevent sharp, sudden changes in pH (neutralization). Produced naturally by the body to maintain homeostasisProduced naturally by the body to maintain homeostasis Weak Acid Weak Base

Chapter 4~ Carbon & the Molecular Diversity of Life Slide shows combined and modified from:

Organic chemistry is the study of CARBON compounds Can form FOUR stable covalent bonds at same time (=tetravalence) Common partners = O, H, N

4 covalent CARBON BONDS form a shape called a TETRAHEDRON Tetrahedron modified from:

Images from: TETRAVALENCE makes large complex molecules with a variety of shapes possible

AP Biology by Campbell and Reese; ©Benjamin Cummings 2005

Hydrocarbons Only carbon & hydrogen (Ex: petroleum; lipid ‘tails’) Covalent bonding; nonpolar High energy storage

Carbon compounds Skeleton may have single or double bonds

AP Biology by Campbell and Reese; ©Benjamin Cummings 2005

ISOMERS- compounds that have the same number of atoms but different structures

STRUCTURAL isomers differing covalent bonding arrangement C 6 H 12 O 6

GEOMETRIC isomers - differ in arrangement around a DOUBLE BOND trans- form cis- form

Be Careful! Single bonds can rotate!... it’s still the same stuff

ENANTIOMER isomers - differ in arrangement around a ASYMMETRIC carbon... Mirror images AP Biology by Campbell and Reese; ©Benjamin Cummings 2005

Functional Groups Hydroxyl Group Ex: alcohols polar (oxygen); soluble in water Names typically end in -ol Ex: Ethanol

Functional Groups Carbonyl Group KETONE: within carbon skeleton ALDEHYDE: at end of carbon skeleton

GLUCOSE is an ALDEHYDE FRUCTOSE is a KETONE GLUCOSE FRUCTOSE

Functional Groups Carboxyl Group Ex: carboxylic acids; polar

Functional Groups Amino Group Called: amines Ex: amino acids (have both amino & carboxyl groups)

H | R -C -COO- | +NH 3 Functional Groups Amino Group Can act as a base and pick up a H + ion Carboxyl Group can act as an acid and give up a H + ion

Functional Groups Sulfhydral Group Called: thiols

DISULFIDE BRIDGES Disulfide bridges stabilize protein structure LYSOZYME

Functional Groups Phosphate Group phosphate ion Makes molecule negatively charged Can store & transfer energy ~ ATP

Functional Groups METHYL Group Makes molecule more NON-POLAR METHYLATION: Adding methyl groups to DNA “turns off” genes

BUILDING BIOMOLECULES tml