Polar; oxygen is more electronegative

Can form hydrogen bonds with water molecules, helping dissolve organic compounds.

are either keytones (in carbon skeleton) or aldehydes (at end of carbon skeleton); thes may be structural isomers

found in sugars; allows for aldoses and ketoses sugars to exist

forms carboxylic acids, or organic acids

has acidic properties because the oxygen-hydrogen bond is so polar

found in cells in the ionized form with a charge of -1 and is called a carboxylate ion

called amines

acts as a base; can pick up H⁺

+1 charge in cells

called Thiols

two sulfhydryl groups can react, forming a covalent bond in a process called "cross-linking", which helps stabilize protein strucure

cross-linking of cysteines in hair maintains curliness or straightness

contributes negative charge of 2- at the end of a molecule and a charge of 1- in the middle

can react with water, releasing energy

addition of a methyl group to DNA, or to molecules bound to DNA, affects gene expression

methyl group arrangement in male and female sex hormones affects their shape and function