AP Biology Unit 1.1 - 1.3

AP Biology Unit 1.1 - 1.3

Hydrogen Bonding

Weak attraction between a partially positive hydrogen and a nearby electronegative atom

Cohesion

Attraction between water molecules caused by hydrogen bonds

Adhesion

Attraction between water molecules and other polar or charged substances

Surface Tension

Resistance of a liquid surface to breaking caused by strong cohesion among surface molecules

Evaporative Cooling

Evaporation removes the highest-energy molecules lowering the temperature of the remaining liquid

Hydrophilic and Hydrophobic Substances

Hydrophilic substances interact with water

hydrophobic substances are nonpolar and avoid mixing with water

Water as a Solvent

Its polarity allows it to surround and dissolve many ionic and polar substances

Water Polarity and Polar Covalent Bonds

Unequal electron sharing in O-H bonds gives oxygen a partial negative charge and hydrogens partial positive charges

High Specific Heat of Water

It resists temperature change because much energy is needed to disrupt hydrogen bonds

High Heat of Vaporization of Water

A large amount of energy is required for evaporation because many hydrogen bonds must break

CHNOPS

"Carbon

Carbon

Hydrogen

Macromolecule Element Composition

"Carbohydrates: CHO

proteins: CHONS

lipids: mostly CHO

phospholipids include P

nucleic acids: CHONP"

Carbon Tetravalence

Carbon has four valence electrons and can form four covalent bonds

Carbon Skeleton

A chain or ring of bonded carbon atoms that forms an organic molecule's framework

Nitrogen in Biological Molecules

Nitrogen is found in amino groups and is required in proteins and nucleic acids

Phosphorus in Biological Molecules

Phosphorus is part of phosphate groups in nucleic acids and phospholipids

Sulfur in Biological Molecules

Sulfur occurs in some amino acids and is used in building proteins

Functional Groups

"Specific atom groups attached to carbon skeletons that determine molecular properties and include hydroxyl

Dehydration Synthesis / Condensation Reaction

Joins monomers by removing H and OH to form water and a covalent bond

Hydrolysis

Breaks covalent bonds by adding water splitting polymers into smaller molecules or monomers

Covalent Bond

A chemical bond formed when atoms share one or more pairs of electrons

Lipids

Hydrophobic molecules such as fats and phospholipids that usually are not true polymers

Structure Determines Function

A molecule's shape and bonding pattern determine what it can do in cells

Monomer

Polymer

Carbohydrates

Monosaccharides

Proteins

Amino Acids

Nucleic Acids

Nucleotides