Lecture 5: Organic Chemistry and Macromolecules

A collection of vocabulary terms from the Organic Chemistry lecture covering isomers, hydrocarbon naming, functional groups, and the four main biological macromolecules.

Structural isomers

Molecules that differ in the placement of their covalent bonds.

Geometric isomers

Molecules with similar placement of covalent bonds but that differ in how bonds are made to surrounding atoms.

Enantiomers

Molecules that share the same chemical structure and bonds but have different 3D placement of their atoms; they are non–superimposable mirror images.

Expanded formula

A way of writing molecules that shows every atom and every bond individually.

Condensed formula

A notation that represents the organic molecule structure by listing atoms in the order they are bonded, such as $CH_3-CH_2-CH_3$.

Skeletal structure

A simplified way of showing a hydrocarbon chain where there is a single carbon atom and necessary hydrogen atoms at each end of a line and at each angle.

Alkanes

Saturated hydrocarbons containing only single bonds, such as But-ane.

Alkenes

Unsaturated hydrocarbons containing at least one double bond ($C=C$), such as Eth-ene.

Alkynes

Unsaturated hydrocarbons containing at least one triple bond ($C \equiv C$), such as Prop-yne.

Monomers

Single building blocks that make up most macromolecules.

Polymers

Large molecules made of monomers held together by covalent bonds.

Dehydration synthesis

A reaction where a water molecule ($H_2O$) is formed when monomers join to become polymers.

Hydrolysis Reactions

A reaction where a water molecule is used to break down polymers into monomers.

Triglycerides

A molecule composed of a glycerol head and $3$ fatty acid chains used for long-term energy storage.

Phospholipids

Amphipathic molecules with a hydrophilic phosphate head and two hydrophobic fatty acid tails; they are a major component of the plasma membrane.

Steroids

Lipids composed of carbon rings, typically containing $17$ carbon atoms bonded in four fused rings.

Glycosidic bond

The specific type of covalent bond that links monosaccharides together into carbohydrates.

Peptide bonds

The type of covalent bond that links amino acids together to form proteins.

Primary structure

The first level of protein folding where amino acid monomers are joined into polypeptide chains via peptide bonds.

Secondary structure

The level of protein folding where polypeptide chains form $\alpha$ helices or $\beta$ pleated sheets, stabilized by hydrogen bonds.

Denaturation

A loss of protein function caused by a change in shape due to changes in temperature, pH, or chemical exposure.

Nucleoside

A component of a nucleic acid made of a pentose sugar and a nitrogen-containing base.

Nucleotides

The monomers of nucleic acids composed of a pentose sugar, a nitrogen-containing base, and a phosphate group.

Hydroxyl group

A functional group represented as R-OH, belonging to the class of alcohols like Ethanol.

Carboxyl group

A functional group represented as $R-COOH$; it is charged and acidic because it ionizes to release $H^+$.

Amino group

A functional group represented as $R-NH_2$; it is charged and basic because it accepts $H^+$ to form $NH_3^+$.

Phosphate group

A group involved in high energy bonds (like in ATP) that is charged and acidic because it ionizes to release $H^+$.

Sulfhydryl group

A functional group represented as R-SH, belonging to the class of compounds known as thiols.