Prokaryotic vs. Eukaryotic Cells – Key Vocabulary

Vocabulary flashcards summarizing the distinguishing structures, components, and characteristics of prokaryotic and eukaryotic cells.

Prokaryotic Cell

Simple, small cell type lacking a nucleus and membrane-bound organelles; always unicellular; domains Bacteria and Archaea

pro- before
karyon- nucleus

Eukaryotic Cell

Larger, more complex cell containing a membrane-bound nucleus and organelles; may be unicellular or multicellular; includes animals, plants, fungi, and protists

eu- true

Nucleus

Double-membrane compartment in eukaryotes that houses linear DNA and controls cellular activities

Membrane-Bound Organelles

Specialized internal compartments surrounded by membranes (e.g., mitochondria, ER, Golgi) found only in eukaryotic cells

Plasma Membrane

Phospholipid bilayer forming the outer boundary of all cells, regulating entry and exit of substances

Cytoplasm

Cellular region between the plasma membrane and nuclear envelope; consists of cytosol and suspended structures

Ribosome

Protein-synthesizing particle; 70S size in prokaryotes, 80S in eukaryotes

DNA

Genetic material of all cells; typically circular in prokaryotes and linear in eukaryotes

Cell Wall

Rigid protective layer outside the plasma membrane; peptidoglycan in bacteria, cellulose in plants, chitin in fungi

Flagellum

Long whip-like appendage used for movement; simple protein filament in prokaryotes, microtubule-based in eukaryotes

Cytoskeleton

Network of protein filaments that maintains cell shape and enables movement; prominent in eukaryotes, absent in prokaryotes

Domain Bacteria

One of the two prokaryotic domains; includes true bacteria with peptidoglycan cell walls

Domain Archaea

Prokaryotic domain with unique lipids and RNA polymerase; often inhabits extreme environments

Protist

Diverse group of mostly unicellular eukaryotes such as amoebae and algae

Fungi

Kingdom of eukaryotic organisms with chitinous cell walls; includes molds, yeasts, and mushrooms

Chloroplast

Photosynthetic, double-membrane organelle in plants and algae that converts light energy to chemical energy

Mitochondrion

ATP-producing, double-membrane organelle responsible for aerobic respiration in eukaryotes

Endoplasmic Reticulum (ER)

Extensive membranous network; rough ER synthesizes proteins, smooth ER synthesizes lipids and detoxifies

Golgi Apparatus

Stack of flattened sacs that modifies, sorts, and packages proteins and lipids for secretion or internal use

Lysosome

Membrane-bound vesicle containing hydrolytic enzymes for intracellular digestion in eukaryotes

Capsule

Sticky polysaccharide layer outside some bacterial cell walls that offers protection and aids in adhesion

Pilus (Pili)

Hair-like surface appendage in bacteria used for attachment or DNA transfer during conjugation

Nucleoid

Region of the prokaryotic cytoplasm where circular DNA is concentrated

Prokaryotic Cell Size

Typically 0.1–5.0 µm in diameter, much smaller than eukaryotic cells

Eukaryotic Cell Size

Typically 10–100 µm in diameter, allowing compartmentalization and greater complexity