Cheat Sheet 1: Biochemistry

Atoms

Single unit made up of neutrons, protons, and electrons

Ionic Bonds

Transfer of e- from one atom to another atom of very different electronegativity

Hydrolysis

Uses water to break polymers into monomers

Dehydration Reaction

Links monomers to form polymers, forming H2O in the process

Covalent Bonds

Sharing of e- between atoms of similar electronegativities

Molecule

Groups of 2+ atoms held together by chemical bonds due to electron interactions

Nonpolar

Equal e- sharing

Polar

Unequal e- sharing, forms dipole

Macromolecules

Large molecules (polymers) formed from the bonding of smaller molecules (monomers)

Hydrogen Bonds

Weak bond between a hydrogen atom and an electronegative atom (F, O, or N)

Monomer (Amino acid)

Building block of proteins

Monomer (Monosaccharide)

Building block of carbohydrates

Monomer (Nucleotide)

Building block of nucleic acids

Polymer (Peptide)

Chain of amino acids linked by peptide bonds

Polymer (Polysaccharide)

Chain of monosaccharides linked by glycosidic bonds

Polymer (Nucleic acid)

Chain of nucleotides linked by phosphodiester bonds

Polymer (Hydrocarbon chain)

Chain of hydrocarbons linked by covalent carbon-carbon bonds

Function of Lipids

Store energy

Function of Nucleic Acids

Encode, express, and store genetic info

Function of Proteins

Structure, transport, defense, storage, enzymes

Function of Lipids

Insulation, energy storage, endocrine signaling, cell structure

Triglycerides

Glycerol + 3 fatty acids

Phospholipids

2 fatty acids + phosphate group attached to glycerol backbone

Steroids

Three 6-membered rings + one 5-membered ring

DNA Structure

Bases are A, T, C, G. Contains deoxyribose sugar and 2 complementary antiparallel (5' to 3') strands of double helix.

RNA Structure

Has bases A, U, C, and G, with a ribose sugar and is single stranded.

Chargaff's Rule

A & T, and G & C are always present in equal amounts (i.e., if DNA is 20% A, it is also 20% T).