Cell Biology: Key Vocabulary

Vocabulary flashcards covering fundamental terms, scientists, organelles, and cell structures referenced in the lecture notes on cell biology.

Cell

The basic structural and functional unit of all living organisms.

Cytology

The scientific study of cells.

Robert Hooke

Scientist who first described cells in 1665.

Anton van Leeuwenhoek

Discovered protozoa and bacteria with his microscopes (1670s).

Robert Brown

Identified the cell nucleus (1831).

Albert von Kölliker

Credited with discovering mitochondria.

Prokaryotic Cell

Simple cell type lacking a nucleus and membrane-bound organelles (bacteria, archaea).

Eukaryotic Cell

Complex cell type with a nucleus and membrane-bound organelles (plants, animals, fungi, protists).

Nucleoid

Region in a prokaryote where DNA is concentrated.

Peptidoglycan

Structural polysaccharide forming most bacterial cell walls.

Capsule (Bacterial)

Polysaccharide layer outside the cell wall that aids attachment and protection.

Flagellum

Long whip-like structure used for cell motility.

Pilus (plural: Pili)

Hair-like appendage used by bacteria for conjugation (DNA transfer).

Fimbria

Short bacterial projection that helps cells adhere to host surfaces.

Organelle

Specialized membrane-bound structure within a eukaryotic cell.

Golgi Apparatus

Organelle that modifies, packages, and ships proteins and lipids.

Mitochondrion

Organelle that produces ATP; the “powerhouse” of the cell.

Endoplasmic Reticulum

Membranous network for protein (rough ER) and lipid (smooth ER) synthesis.

Chloroplast

Plant plastid containing chlorophyll; site of photosynthesis.

Nucleus

Organelle that houses eukaryotic DNA and directs cell activities.

Cell Theory

Principle stating all organisms are made of cells, the cell is life’s basic unit, and cells arise from pre-existing cells.

Zacharias Janssen

Early microscope maker (c. 1590) who aided in cell discovery.

Theodor Schwann

Zoologist who concluded all animals are made of cells.

Matthias Schleiden

Botanist who concluded all plants are made of cells.

Rudolph Virchow

Proposed that cells arise only from pre-existing cells (1855).

Cell Wall

Rigid outer layer in plants, fungi, and many prokaryotes that provides support and protection.

Plastid

Plant organelle involved in storage or pigmentation (e.g., chloroplast, chromoplast).

Chromoplast

Plastid containing colored pigments that give fruits and flowers their hues.

Leukoplast

Colorless plastid specialized for storage (e.g., starch, lipids, proteins).

Amyloplast

Type of leukoplast that stores starch (e.g., in potatoes).

Elaioplast

Leukoplast that stores lipids.

Proteinoplast

Leukoplast that stores proteins.

Nuclear Envelope

Double membrane surrounding the nucleus; contains nuclear pores.

Chromatin

DNA-protein complex forming chromosomes within the nucleus.

Nucleoplasm

Gel-like fluid inside the nucleus.

Nucleolus

Dense nuclear region where ribosomal RNA is synthesized.

Centrosome

Animal-cell organelle containing centrioles; organizes microtubules.

Lysosome

Vesicle containing hydrolytic enzymes for intracellular digestion.

Phospholipid Bilayer

Double layer of phospholipids forming the fundamental structure of cell membranes.

Integral Protein

Membrane protein embedded within the lipid bilayer; often functions as transporter or receptor.

Peripheral Protein

Membrane protein loosely attached to the bilayer surface; involved in signaling and support.

Cholesterol (Membrane)

Steroid that modulates membrane fluidity and stability.

Carbohydrate (Cell Membrane)

Sugar chain attached to lipids or proteins; functions in cell recognition and adhesion.

Stem Cell

Undifferentiated cell capable of giving rise to specialized cell types.

Osteocyte

Mature bone cell maintaining bone tissue.

Erythrocyte

Red blood cell specialized for oxygen transport.

Myocyte

Muscle cell that contracts to produce movement.

Adipocyte

Fat cell specialized for lipid storage.

Neuron

Nerve cell that transmits electrical and chemical signals.

Endothelial Cell

Cell lining blood and lymphatic vessels.

Gamete

Sex cell (sperm or egg) carrying half the genetic information.

Beta Cell (Pancreatic)

Pancreatic cell type that secretes insulin.

Cancer Cell

Cell that divides uncontrollably and can invade other tissues.