Biochemistry & Chemistry Review: Water, Reactions, Organic Molecules, and Bonding

Water

Main source of fluids: beverages + some foods.

Functions of Water

Maintains body temperature, cushions joints, removes waste (urination, perspiration, bowel movements).

Cells water content

~70% water → water is polar and central to cellular reactions.

Hydrophilic

Water-loving (polar).

Hydrophobic

Water-fearing (nonpolar).

Amphiphilic

Both polar and nonpolar.

Monomer

Single unit.

Dimer

2 monomers.

Oligomer

Few monomers (~4-12).

Polymer

Many monomers → formed by polymerization.

Dehydration Synthesis (DSR)

Joins monomers → polymer; one molecule gives -OH, the other -H → forms H2O; forms -O- bond.

Hydrolysis (HR)

Breaks polymer → monomers; water added; -H attaches to one fragment, -OH to the other; breaks -O- bond.

Redox Reactions

Transfer of electrons between molecules; Oxidation = loss of electrons; Reduction = gain of electrons.

OIL RIG

OXIDATION IS LOSS, REDUCTION IS GAIN

Phosphorylation

Addition of phosphate group(s) to a molecule; done by enzymes called kinases.

Carbon

Backbone of organic compounds (4 bonds, very stable).

Hydrocarbons

Only C + H, basis of fuels; can form chains or rings.

MY ELEPHANT PREFERS BANANAS

Special Case for hydrocarbon naming for the first 4

MY = METHANE

ELEPHANT = ETHANE

PREFERS = PROPANE

BANANAS = BUTANE

Then its pent, hex, sept, oct, nona, deca

Hydrocarbon Formula

CnH(2n+2) where n is the number of carbons, eg. 5 carbons = C5H(2 x 5 + 2) = C5H10 Pentane

Double/triple bonds

Drawn as = or ≡.

Functional Groups

Reactive parts of molecules → define chemical behavior.

Hydrophilic Functional Groups

Polar → increases solubility.

Hydrophobic Functional Groups

Nonpolar → decreases solubility.

Electronegativity (EN)

Atom's ability to attract electrons.

∆EN determines bond type

0-0.5 → Nonpolar Covalent (NPC); 0.5-1.7 → Polar Covalent (PC); 1.7 → Ionic (I).

Dipole

Molecule with partial positive & negative ends.