why chemistry, why again?

You are made up of biomolecules! Your biomolecules are built from food you eat Your body breaks them down and rearranges

them to give you:Energy and

Building blocks for proteins, carbohydrates, lipids and

Nucleic acids (DNA, RNA)

Carbohydrates (sugar and starch) Protein Lipids – (fats, oils, cholesterol) Vitamins Minerals (Ca, PO4

-2, Se, Fe, Ni, Zn, etc)

H2O

and Energy (stored in chemical bonds)

elemenelementt

CarbohydrateCarbohydrate LipidsLipids Protein Protein Nucleic Nucleic acidsacids

CC

HH

OO

NN

PP **

SS ****

* phospholipids** some proteins

• Protons• Electrons• Neutrons

• Protons• Electrons• Neutrons

• What are they?

• How do I figure out how many an atom has?

• How do I figure out how many an ion has?

Intermolecular Forces

Intramolecular Forces

Molecular Forces

Dispersion Forces Hydrogen

Bonds

Covalent Bonds

Ionic Bonds

DipoleForces

Ionic

Covalent

Nonpolar Covalent bonds – equal sharing

0.0 < Electronegativity difference ≤ 0.4

Polar Covalent Bond – unequal sharing

0.4 < Electronegativity difference < 1.5

Line becomes arrow from positive to negative

Insulin

Molecular Polarity

CH4

CO2

NH3

H2O

Inter molecular Forces

Intramolecular Forces

Molecular Forces

Dispersion Forces

Hydrogen Bonds

Covalent Bonds

Ionic Bonds

DipoleForces

Bond typeRelative Strength

Covalent 400x

Hydrogen bonds 10x

Dispersion Forces

<1x

Weakest intermolecular force

Caused by the motion of electrons

More electrons per molecule, more attraction between molecules; i.e. halogens

e.g. bromine is a liquid, whereas iodine is a solid at STP

Electrons momentarily gang up on one side of the molecule

Strongest of the intermolecular forces

Only molecules with hydrogen in them

BIG role in living organisms!!!

Hydrogen Bonds

H2O What’s the H, what’s the O? Why the 2? Hydrogen Bonding – a big deal!

solubility (water is the universal solvent)

cohesion adhesion heat retention

Solubility Capillary Action Heat of Vaporization Heat of Fusion Surface Tension Density Differences

Solubility Capillary Action Heat of Vaporization Heat of Fusion Surface Tension Density Differences

Life’s necessity

Paper Towels and Redwood Trees

425 ft

Intermolecular Forces

Intramolecular Forces

Molecular Forces

Dispersion Forces

Hydrogen Bonds

Covalent Bonds

Ionic Bonds

DipoleForces