Biochemistry Lecture Review Flashcards

Vocabulary flashcards covering foundational concepts in biochemistry, early Earth biomolecule experiments, cellular structures and organelles, water chemistry, and acid/base behavior.

Biochemistry

The study, at the molecular level, of the chemical processes that occur in the cells of living organisms.

Miller-Urey Experiment

A 1952 experiment that mimicked early Earth atmosphere conditions (using gases like $NH_3$, $H_2S$, $CO$, $CO_2$, and $H_2O$ with electrical lightning) to demonstrate the spontaneous formation of biomolecules such as amino acids, formaldehyde, and hydrogen cyanide.

Stanley Lloyd Miller

American biologist at UCSD and Ph.D. graduate student of Harold Urey at the University of Chicago who co-conducted the 1952 Miller-Urey experiment.

Harold Clayton Urey

American physical chemist at the University of Chicago who won the 1934 Nobel Prize in Chemistry for the discovery of deuterium and co-conducted the 1952 Miller-Urey experiment.

Prokaryotes

Organisms whose cells lack a true nucleus ("before the nucleus"), such as Escherichia coli.

Eukaryotes

Complex organisms whose cells contain a true nucleus and membrane-bound organelles, such as plants, animals, fungi, and Arabidopsis thaliana.

Nucleus

The cellular organelle that serves as the location of genome storage and the site of DNA and RNA synthesis.

Endoplasmic Reticulum

A cellular transport system involved in the protein synthesis of membrane proteins.

Golgi Apparatus

A cellular organelle responsible for protein secretion, processing, and packaging.

Chloroplast

An organelle found in plant cells that serves as the location of photosynthesis.

Cytoskeleton

The structural scaffolding within cells, composed of components like microtubules, that provides cell shape.

Water Bond Angle

The angle formed by the $O-H$ bonds in a water molecule, measuring $104.3^\times$ (or $104.3^\text{o}$).

Dipole

A pair of equal and opposite electric charges separated by a distance within a molecule or bond.

Solvent

A liquid capable of dissolving a solid, liquid, or gaseous solute.

Hydrophilic

A term meaning "water-loving," describing polar or charged molecules that readily dissolve in water.

Hydrophobic

A term meaning "water-hating," describing nonpolar compounds (such as hydrocarbon chains or oils) that do not mix with water and form separate layers.

Amphipathic Molecule

A molecule containing both hydrophilic (polar) and hydrophobic (nonpolar) regions, such as sodium palmitate.

Micelles

Structures formed by amphipathic molecules in water where polar head groups face outward toward water and nonpolar tails cluster inward away from water.

Ion Product Constant for Water ($K_w$)

The equilibrium constant for the self-ionization of water, defined as $K_w = [H^+][OH^-]$.

Strong Acid

An acid that completely ionizes/dissociates in water, such as hydrochloric acid ($HCl$), sulfuric acid ($H_2SO_4$), hydrobromic acid ($HBr$), or nitric acid ($HNO_3$).

Weak Acid

An acid that undergoes limited or partial ionization in water, such as acetic acid ($CH_3COOH$), phosphoric acid ($H_3PO_4$), hydrofluoric acid ($HF$), or carbonic acid ($H_2CO_3$).

Strong Base

A base that ionizes completely in water, such as sodium hydroxide ($NaOH$), lithium hydroxide ($LiOH$), potassium hydroxide ($KOH$), or barium hydroxide ($Ba(OH)_2$).

Weak Base

A base that undergoes incomplete or partial ionization in water, such as ammonia ($NH_3$), trimethylamine ($N(CH_3)_3$), pyridine ($C_5H_5N$), or methylamine ($CH_3NH_2$).

Acid Dissociation Constant ($K_a$)

A equilibrium constant measuring acid strength; a large $K_a$ indicates a strong acid with higher dissociation, whereas a small $K_a$ indicates a weak acid with lower dissociation.