The Cell: An Overview and Eukaryotic Organelles

Vocabulary flashcards covering the fundamental concepts of cell biology, evolutionary origins, biochemical principles, and eukaryotic organelle structures and functions.

Cell

The fundamental unit of life that embodies repeated concepts of modularity, polarity, and sequencing, and serves as the vehicle for hereditary information.

Physics

The natural science of matter, involving its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force.

Chemistry

A physical science that studies the properties and behavior of matter, covering elements and compounds made of atoms, molecules, and ions: their composition, structure, properties, behavior, and the changes they undergo during reactions.

Evolution

The change in heritable characteristics of biological populations over successive generations, driven by processes such as natural selection and genetic drift acting on genetic variation.

Natural Selection

The differential survival and reproduction of individuals due to differences in phenotype, serving as a primary mechanism of evolution.

Prokaryotic Cell

A cell type that contains neither a nucleus nor membrane-bound organelles, derived from "pro" meaning before and "karyon" meaning nucleus.

Eukaryotic Cell

A cell type characterized by membrane-bound organelles and a central nuclear organelle, derived from "eu" meaning true and "karyon" meaning nucleus.

Bacterial Morphologies

The morphological classifications of bacteria, including spherical cells (e.g., Streptococcus), rod-shaped cells (e.g., Escherichia coli, Vibrio cholerae), the smallest cells (e.g., Mycoplasma, Spiroplasma), and spiral cells (e.g., Treponema pallidum).

Taxonomic Ranking

The hierarchical biological classification system ordered from broadest to most specific: Domain, Kingdom, Phylum, Class, Order, Family, Genus, and Species (exemplified by Vulpes vulpes).

Symbiogenesis

The evolutionary theory (or serial endosymbiotic theory) stating that eukaryotic organelles such as mitochondria and chloroplasts originated from formerly free-living prokaryotes engulfed in endosymbiosis.

Artery Tissue Architecture

The complex structural layers of an artery wall consisting of the tunica adventitia (TA), tunica media (TM), tunica intima (TI), endothelial cells (EC), and the central lumen (Lu).

Glycocalyx

A carbohydrate-rich zone located on the external surface of the plasma membrane of eukaryotic cells.

Amino Acid

The modular building block of proteins consisting of a central $\alpha$-carbon bonded to an amino group ($-NH_3^+$), a carboxyl group ($-COO^-$), a hydrogen atom, and a variable side chain ($R$).

Peptide Bond

A covalent linkage formed between the carboxyl carbon of one amino acid and the amino nitrogen of another via a condensation reaction that releases a molecule of $H_2O$.

Hydrolysis

A chemical cleavage reaction in which a covalent bond in a polymer is broken by the addition of water ($H^+$ and $OH^-$), releasing free monomer subunits.

Autocatalytic Process

The cycle of life in which polynucleotides provide sequence information to specify proteins, and proteins provide the catalytic function required to replicate and transcribe polynucleotides.

Adenosine Triphosphate (ATP)

The primary energy currency generated by photosynthesis or respiration that fuels macromolecule synthesis, molecular transport against concentration gradients, cellular movements, and electric potential generation.

Lysosome

A single-membrane organelle with an internal lumen pH of approximately $5.0$ containing acid hydrolases (such as nucleases, proteases, and lipases) that degrade cellular components and endocytosed material.

Peroxisome

A single-membrane eukaryotic organelle containing oxidases and catalase that is responsible for degrading fatty acids and toxic compounds.

Mitochondrion

A double-membraned organelle consisting of an outer membrane, intermembrane space, inner membrane folded into cristae, and a matrix, serving as the site of ATP generation via aerobic metabolism.

Chloroplast

The photosynthetic organelle of plants and green algae, bounded by a double membrane and containing stroma, thylakoid membranes stacked into grana, and a thylakoid lumen.

Endoplasmic Reticulum (ER)

A network of interconnected closed membrane tubules and vesicles partitioned into rough and smooth regions, responsible for lipid synthesis, membrane protein synthesis, $Ca^{2+}$ ion storage, and detoxification.

Golgi Complex

A stack of flattened membrane-bound cisternae organized into cis (entry), medial, and trans (exit) regions that modifies, sorts, and packages macromolecules received from the endoplasmic reticulum.

Nucleus

The organelle enclosed by a double membrane with nuclear pores that houses the genome, separates DNA from the cytosol, and uncouples transcription from translation.

Cytosol

The compartment of the cell enclosed by the plasma membrane that is not part of any organelle, containing the cytoskeleton, polyribosomes, and metabolic enzymes.