Biochemistry and the Organization of Cells

Vocabulary flashcards covering key terms and definitions from Chapter 1: Biochemistry and the Organization of Cells.

Organic Chemistry

The study of the compounds of carbon, which form the cellular apparatus and biomolecules of living organisms.

Friedrich Wöhler's Experiment (1828)

An experiment demonstrating that an organic compound, urea ($\text{H}_2\text{NCONH}_2$), could be synthesized from an inorganic compound, ammonium cyanate ($\text{NH}_4\text{OCN}$).

Functional Group

An atom or group of atoms that shows characteristic physical and chemical properties.

Big Bang Theory

A cosmological theory stating that all matter was originally confined in a very small space and expanded with great force at an initial temperature of approximately $15 \times 10^9\,K$.

Prebiotic Soup

The early Earth ocean environment ($4.0 - 4.5 \times 10^9$ years ago) containing simple compounds like $\text{NH}_3$, $\text{H}_2\text{S}$, $\text{CO}$, $\text{CO}_2$, $\text{CH}_4$, $\text{N}_2$, $\text{H}_2$, and $\text{H}_2\text{O}$, but almost no oxygen ($\text{O}_2$).

Miller-Urey Experiment

An experiment demonstrating that biomolecules could arise under abiotic conditions using electric discharge and simple gases ($\text{H}_2\text{O}$, $\text{CH}_4$, $\text{NH}_3$, $\text{H}_2$) without oxygen present.

Polymer

A large molecule formed by linking together smaller repeating units called monomers (from Greek poly + meros, meaning many parts).

Monomer

A simple building-block molecule (from Greek mono + meros, meaning single part) that joins with others to form a polymer.

Enzymes

A class of proteins that act as biocatalysts, whose catalytic effectiveness depends on their specific amino acid sequence.

Genetic Code

The relationship between the nucleotide sequence in nucleic acids and the amino acid sequence in proteins.

RNA World

A hypothesis proposing that an early form of RNA capable of coding for and catalyzing its own replication was the pivotal stage in the origin of life.

Double-Origin Theory

A theory on the origin of life proposing that the development of a coding system and the development of catalysis occurred separately before combining.

Prokaryote

A single-celled organism (from Greek meaning "before the nucleus") lacking a definite nucleus surrounded by a nuclear membrane, such as bacteria and cyanobacteria.

Eukaryote

An organism (from Greek meaning "true nucleus") composed of single or multiple cells containing a well-defined nucleus surrounded by a nuclear membrane.

Nucleus

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

Mitochondrion

The site of energy-yielding oxidation reactions within eukaryotic cells, containing its own DNA.

Chloroplast

The site of photosynthesis in green plants and algae, containing grana, a double membrane, and its own DNA.

Endoplasmic Reticulum

A continuous membrane network throughout the cell, whose rough portion is studded with ribosomes for protein synthesis.

Golgi Apparatus

A series of flattened membranous vesicles involved in the secretion of proteins from cells and in reactions linking sugars to other cellular components.

Lysosomes

Membrane-enclosed sacs containing hydrolytic enzymes.

Peroxisomes

Sacs containing enzymes involved in the metabolism of hydrogen peroxide.

Cytoskeleton

A microtrabecular lattice or network of filaments (including microtubules) that maintains cell structure and holds organelles in place within the cytosol.

Five-Kingdom Classification Scheme

A classification scheme dividing organisms into Monera, Protista, Fungi, Plantae, and Animalia based on prokaryotic versus eukaryotic structural differences.

Three-Domain System

A biological classification system based on biochemical traits that categorizes life into Archaea (Archaebacteria), Bacteria (Eubacteria), and Eukarya.

Endosymbiosis

The theory that eukaryotic organelles evolved from symbiotic prokaryotes, such as chloroplasts from cyanobacteria and mitochondria from aerobic bacteria like E. coli.

Exergonic Reaction

A spontaneous chemical reaction that releases energy, characterized by a negative change in free energy ($\Delta G < 0$).

Endergonic Reaction

A nonspontaneous chemical reaction requiring external energy input, characterized by a positive change in free energy ($\Delta G > 0$).

Gibbs Free Energy Equation

The equation $\Delta G = \Delta H - T\Delta S$, where $\Delta G$ is the change in free energy, $\Delta H$ is enthalpy change, $T$ is absolute temperature in Kelvin ($K$), and $\Delta S$ is entropy change.

Entropy ($S$)

A thermodynamic measure of disorder in the universe, described statistically by Boltzmann's equation $S = k \ln(W)$.

monera

prokaryotes, such as bacteria

protista

Mostly single-celled eukaryotes, such as amoebas

fungi

Absorb nutrients, such as mushrooms and yeast

plantae

Multicellular photosynthetic organisms

Animaila

multicellular organsims that consume food

Bacteria

common prokaryotic organism

Areachea

Prolarytes genetically and chemically distinct from bacteria

Eukarya

all eukaryotes, including protists, fungi, plants, and anmials

What is a ribozyme

is an RNA molecules that acts like an enzyme and catalyzes a chemical reaction