Prokaryotic vs. Eukaryotic Cells – Vocabulary Review

Vocabulary flashcards summarizing key terms and definitions related to similarities and differences between prokaryotic and eukaryotic cells.

Prokaryotic Cell

Simple cell type lacking a nucleus and membrane-bound organelles; DNA resides in a nucleoid.

Eukaryotic Cell

Complex cell type containing a true nucleus and membrane-bound organelles such as mitochondria.

Ribosome

Organelle where protein synthesis occurs; present in both prokaryotes and eukaryotes.

70S Ribosome

Smaller ribosome found in prokaryotic cells; target of many antibiotic drugs.

80S Ribosome

Larger ribosome found in eukaryotic cells.

Svedberg Unit (S)

Unit of sedimentation rate used to describe ribosome size during ultracentrifugation.

Selective Toxicity

Drug property that exploits differences (e.g., 70S vs. 80S ribosomes) to harm microbes without harming host cells.

Protein Synthesis

Process of building proteins on ribosomes using mRNA templates.

Nucleus

Membrane-bound structure in eukaryotes that houses DNA.

Nucleoid

Irregular region in prokaryotes where the bacterial chromosome is located.

Mitochondria

Eukaryotic organelle known as the “powerhouse of the cell” where ATP is produced.

ATP (Adenosine Triphosphate)

Primary energy currency of the cell, generated in mitochondria or via other pathways in prokaryotes.

Membrane-Bound Organelles

Structures enclosed by membranes (e.g., ER, Golgi) found only in eukaryotic cells.

Endoplasmic Reticulum (ER)

Network of membranous sacs involved in protein and lipid processing in eukaryotes.

Rough ER

Endoplasmic reticulum studded with ribosomes; site of protein synthesis.

Smooth ER

Endoplasmic reticulum lacking ribosomes; involved in lipid synthesis and detoxification.

Golgi Apparatus

Eukaryotic organelle that modifies, packages, and sorts proteins for secretion or internal use.

Flagella

Long whip-like structures used for cell movement; found in some prokaryotes and eukaryotes (e.g., sperm).

Cell Wall

Rigid outer layer present in many cells; composition differs—peptidoglycan in bacteria, other materials in algae/fungi.

Peptidoglycan

Polymer forming the main component of most bacterial cell walls.

Cytoplasm

Gel-like interior of the cell composed mainly of water, salts, and organic molecules.

Plasma Membrane

Phospholipid bilayer surrounding all cells, controlling entry and exit of substances.

Phospholipid Bilayer

Two-layered arrangement of phospholipids forming the basic structure of plasma membranes.

Transmembrane Protein

Protein that spans the plasma membrane, facilitating communication or transport.

Protein Channel

Transmembrane protein forming a pore to allow ions or molecules to cross the membrane.

Pili

Hair-like appendages on prokaryotes aiding in attachment to host cells.

Fimbriae

Short, numerous prokaryotic structures that promote adhesion to surfaces or host cells.

Endospore

Highly resistant, dormant structure formed by some bacteria during unfavorable conditions.

Sporulation

Process by which a bacterial cell forms an endospore to protect its genetic material.

Germination

Return of an endospore to a metabolically active, growing bacterial cell once conditions improve.

Glycocalyx

Sticky polysaccharide layer secreted outside some prokaryotic cells; may form a capsule.

Capsule

Well-organized, thick glycocalyx that aids bacterial attachment and evasion of phagocytosis.

Phagocytosis

Immune process of engulfing and destroying pathogens; capsules help bacteria evade it.