Miller-Urey and Biochemistry Vocabulary Flashcards

52 vocabulary flashcards covering key terms and concepts from the lecture notes.

Miller-Urey experiment

A classic experiment showing abiotic synthesis of organic molecules (e.g., amino acids) under primitive Earth–like conditions.

Abiotic compound

A chemical not produced by living systems; non-living origin.

Biotic molecule

A molecule typically found in living systems.

Abiotic vs biotic

Difference between non-living (abiotic) and life-associated (biotic) molecules.

Organic compound

A carbon-containing molecule; can be non-living or living.

Amino acid

Building block of proteins; can be formed abiotically in some experiments.

Protein

Polymers of amino acids that perform most cellular functions.

Nucleic acid

Polymers such as DNA/RNA that store genetic information.

Urea

The first biotic molecule synthesized in the lab; historically significant.

Ammonia

A simple abiotic molecule cited as an example of non-living chemistry.

Hydrocarbon

Molecule composed only of hydrogen and carbon; nonpolar and energy-rich.

Hydrophobic

Water-fearing; nonpolar; tends to separate from water.

Nonpolar

Lacks significant charge separation; not attracted to water.

Planar

Flat geometry; often due to carbon–carbon double bonds.

Tetrahedral

Three-dimensional geometry around carbon in single-bonded structures.

Double bond

A bond between two carbons (or atoms) that creates planarity and restricts rotation.

Cis isomer

Substituents on the same side of a carbon–carbon double bond.

Trans isomer

Substituents on opposite sides of a carbon–carbon double bond.

Enantiomer

A non-superimposable mirror-image form of a molecule.

Chiral

Molecule with a non-superimposable mirror image (often due to a stereocenter).

Isomer

Compounds with the same formula but different arrangement of atoms.

Estradiol

Female sex hormone; a steroid.

Testosterone

Male sex hormone; a steroid.

Steroid

Lipid with a four-ring core structure; highly hydrophobic.

Four-ring core

The central four fused hydrocarbon rings found in steroids.

Methyl group

CH3 group; nonpolar and hydrophobic.

Hydroxyl group

OH group; polar and capable of hydrogen bonding.

Carbonyl group

C=O group; polar and hydrogen-bond accepting.

Carboxyl group

COOH group; acidic; can donate a proton and form hydrogen bonds.

Amine (amino) group

NH2 group; basic; accepts a proton.

Sulfhydryl group

SH group; sulfur-containing; can participate in bonding.

Phosphate group

PO4 group; highly polar and negatively charged at physiological pH.

ATP

Adenosine triphosphate; high-energy molecule releasing energy when a phosphate is removed.

Hydrogen bond

Bond between a hydrogen atom and a highly electronegative atom; crucial for structure and solubility.

Hydrophilic

Water-loving; polar or charged; dissolves in water.

Amphipathic

Molecule with both hydrophobic and hydrophilic parts.

Emulsifier

Molecule that helps mix oil and water by presenting both polar and nonpolar parts.

Membrane

Lipid bilayer forming cell boundaries; interior is hydrophobic.

Physiological pH

Typical cellular pH around 7.4 where many groups carry charge.

Titratable group

Group that can gain or lose a proton to become charged.

Carboxyl as acid

Carboxyl group behaves as an acid, donating a proton.

Amino as base

Amine group behaves as a base, accepting a proton.

Protonation

Gain of a proton by a molecule, increasing its positive charge.

Deprotonation

Loss of a proton by a molecule, increasing its negative charge.

Charge states in biology

Possible charges: plus/minus 1 or 2; zero; partial charges are not counted as charged.

Partial charge

Small, non-integer charge distribution due to polarity; not a full charge.

Phosphate in biology

Phosphate groups are generally negatively charged in DNA/RNA and ATP.

Energy-rich fats

Fats store a lot of chemical energy due to long hydrocarbon chains.

Gasoline

A hydrocarbon mixture used as fuel; energy-dense.

Long hydrocarbon chains

Extended C–H chains that store substantial energy in fats and fuels.

Decorating rings

Moving functional groups around a steroid ring to change its function.

Cis fats and trans fats

Fats defined by whether the arrangement around a double bond is on the same (cis) or opposite (trans) side.

Nucleic acids (overview)

Biomolecules like DNA/RNA that encode genetic information; can be produced abiotically in some experiments.

Amino acids (overview)

Building blocks of proteins; can be synthesized in lab simulations of early Earth.

Proteins (overview)

Biomolecules composed of amino acids; perform most cellular functions.

Nucleic acids in biology

Backbone typically contains phosphate groups; often negatively charged.

Amino group as base

Amino group accepts protons to become positively charged.

Carboxyl as acid

Carboxyl group donates a proton to become negatively charged.

Protonation

Gain of a proton by a molecule, altering its charge.

Deprotonation

Loss of a proton by a molecule, altering its charge.

Hydrogen bond donors/acceptors

Groups that can donate or accept hydrogen bonds influence solubility.

Planar vs nonplanar in rings

Double bonds favor planarity; single bonds allow more 3D flexibility.

Fats as energy source

Fatty acids and triglycerides provide concentrated energy store.