Isomers, Enantiomers, Functional Groups, and ATP - Vocabulary Flashcards

A set of vocabulary flashcards covering key concepts from the notes on isomers (structural, cis-trans, enantiomers), chirality, pharmacology examples (ibuprofen, albuterol, L-/D-/R-/S- enantiomers, L-DOPA), functional groups (hydroxyl, carbonyl, aldehyde, ketone, carboxyl, amino, sulfhydryl, phosphate, methyl), and ATP-related chemistry (hydrolysis, phosphorylation, central dogma).

Isomer

A compound that has the same molecular formula as another compound but a different arrangement of atoms, resulting in different properties.

Structural isomer

Isomers that differ in how atoms are covalently connected (connectivity); same formula but different structure.

Cis-trans isomer

Geometric isomers differing in spatial arrangement around a double bond or ring; cis = same side, trans = opposite sides.

Enantiomer

One of a pair of molecules that are non-superimposable mirror images of each other; same formula and connectivity but different 3D orientation.

Chirality

Property of a molecule that makes it non-superimposable on its mirror image, leading to enantiomers.

L-enantiomer

The left-handed form of a chiral molecule (L-); often biologically relevant in enzymes and receptors.

D-enantiomer

The right-handed form of a chiral molecule (D-); the mirror counterpart to the L-enantiomer.

R-enantiomer

Configuration where CIP priorities give a clockwise arrangement around the chiral center.

S-enantiomer

Configuration where CIP priorities give a counterclockwise arrangement around the chiral center.

Ibuprofen S-enantiomer

The S-enantiomer is the pharmacologically active form of ibuprofen; the R-enantiomer is less active or inactive.

Albuterol enantiomers

Enantiomers of albuterol can have different pharmacological activity; one form may be more effective at bronchodilation.

L-DOPA

The L-enantiomer of DOPA that reduces Parkinson's disease symptoms; the D-enantiomer has little or no effect.

Functional group

A recognizable group of atoms attached to a carbon skeleton that largely determines chemical behavior; examples include hydroxyl, carbonyl, carboxyl, amino, phosphate, and methyl groups.

Hydroxyl group

–OH; polar; forms hydrogen bonds; found in alcohols (e.g., ethanol) and contributes to solubility.

Carbonyl group

C=O group; can be an aldehyde (at the end) or a ketone (in the middle) depending on position.

Aldehyde

A carbonyl group at the end of a carbon chain; sugars with aldehydes are aldoses.

Ketone

A carbonyl group within the carbon skeleton; sugars with ketones are ketoses (e.g., acetone as a simple example).

Carboxyl group

–COOH; acts as an acid by donating a hydrogen ion (H+) in solution; forms carboxylic acids.

Amino group

–NH2; acts as a base by accepting protons; common in amino acids.

Sulfhydryl group

–SH; forms disulfide cross-links that help stabilize proteins; known as thiols.

Phosphate group

–PO4H2; organic phosphate; energy-rich in molecules like ATP and involved in energy transfer.

Methyl group

–CH3; methylation can affect DNA, proteins, and hormones; influences shape, function, and gene expression.

ATP

Adenosine triphosphate; the energy currency of the cell, consisting of adenosine and three phosphate groups; hydrolysis releases energy.

ATP hydrolysis

Reaction of ATP with water that yields ADP and inorganic phosphate (Pi) and releases usable energy for cellular work.

Phosphorylation

Addition of a phosphate group to a molecule; can store energy and drive cellular processes; the reverse is dephosphorylation.

Central dogma

The flow of genetic information: DNA → RNA → Protein; RNA serves as an intermediate between DNA and protein.

Isomers

Compounds with the same molecular formula but different three-dimensional structures, leading to different properties and behaviors.

Structural (constitutional) isomers

Isomers that differ in covalent connectivity or arrangement of atoms (e.g., branched versus linear skeletons).

Stereoisomers

Isomers with the same connectivity but different spatial arrangement.

Enantiomers

Non-superposable mirror images of each other, often having different biological effects.

Cis–trans isomers

Isomers that differ in spatial arrangement around a double bond or rigid ring.

Chiral center

A carbon atom bonded to four different groups, leading to the possibility of enantiomers (L and D forms).

Functional groups

Specific groups of atoms attached to a carbon skeleton that largely determine the behavior and reactivity of a molecule.

Hydroxyl group

A functional group (-OH) that is polar and forms hydrogen bonds due to electronegative oxygen (e.g., in ethanol).

Carbonyl group

A functional group (C=O) that can be an aldehyde (at the end of a chain) or a ketone (within the chain).

Carboxyl group

A functional group (-COOH) consisting of a carbonyl attached to a hydroxyl on the same carbon, acts as an acid by donating a proton.

Amino group

A functional group (-NH₂) containing nitrogen, acts as a base by accepting a proton (found in amino acids).

Sulfhydryl group

A functional group (-SH) that can form disulfide cross-links, stabilizing protein structures.

Phosphate group

A functional group (-PO₄H₂ or -PO₄) that is highly electronegative and important in energy-releasing reactions and energy transfer (e.g., in ATP).

Methyl group

A functional group (-CH₃) that can influence gene expression through DNA methylation or alter molecule shape and function (e.g., in steroids).

Central Dogma

The flow of genetic information from DNA to RNA to Protein (\text{DNA} \rightarrow \text{RNA} \rightarrow \text{Protein}).

DNA Methylation

The addition of methyl groups to DNA (e.g., 5-methylcytosine) which can turn genes on or off, affecting transcription and protein production.

ATP (Adenosine Triphosphate)

The energy currency of the cell, consisting of adenosine + three phosphate groups linked by high-energy bonds. Releases energy via hydrolysis (\mathrm{ATP} + ext{H}2 ext{O} \rightarrow ext{ADP} + ext{P}i + \text{energy}).

L-DOPA

An enantiomer that reduces Parkinson’s symptoms, illustrating how subtle stereochemical variations can have dramatically different clinical outcomes.