General Biology 1 – The Cell (Vocabulary Review)

A comprehensive set of vocabulary flashcards covering fundamental cell biology terms, scientists, organelles, and processes from the General Biology 1 lecture.

Cell

The basic unit of life; the smallest structure capable of performing all activities required for life.

Cell Theory

Biological principle stating that (1) all organisms are composed of cells, (2) the cell is the basic unit of life, and (3) all cells arise from pre-existing cells.

Robert Hooke

British scientist who, in 1665, coined the term “cells” after observing cork under a microscope.

Anton van Leeuwenhoek

Dutch scientist who improved the microscope and discovered living “animalcules,” including protists and sperm, in the late 1600s.

Matthias Schleiden

German botanist who concluded in 1838 that all plants are composed of cells.

Theodor Schwann

German zoologist who declared in 1839 that all animals are made of cells.

Rudolf Virchow

German scientist who added “Omnis cellula e cellula” (cells arise from cells) to cell theory in 1858.

Plasma Membrane

The selectively permeable outer boundary of the cell that regulates substance exchange and protects internal components.

Fluid Mosaic Model

Description of the plasma membrane as a dynamic, fluid layer of phospholipids with embedded proteins and cholesterol.

Phospholipid Bilayer

Two layers of phospholipids with hydrophobic tails inward and hydrophilic heads outward, forming the membrane’s foundation.

Cholesterol

Ring-shaped lipid interspersed in animal membranes that modulates fluidity and stability.

Integral Protein

Membrane protein embedded through the bilayer; often functions in transport or signaling.

Peripheral Protein

Membrane protein attached to the inner or outer surface of the bilayer; aids in support or enzymatic activity.

Cytoplasm

Region between the plasma membrane and nucleus containing cytosol, organelles, and cytoskeleton.

Cytosol

Gel-like aqueous portion of cytoplasm where metabolic reactions occur; ~70 % of cell volume.

Nucleus

Membrane-bound control center of eukaryotic cells that houses DNA and regulates activities.

Nuclear Envelope

Double membrane surrounding the nucleus, separating it from cytoplasm.

Nucleolus

Dense nuclear region where ribosomal RNA is synthesized and ribosome subunits assemble.

Endomembrane System

Interconnected group of eukaryotic organelles (ER, Golgi, lysosomes, etc.) that modify, package, and transport lipids and proteins.

Endoplasmic Reticulum (ER)

Network of membranous tubules; rough ER bears ribosomes for protein modification, smooth ER synthesizes lipids and detoxifies chemicals.

Rough ER

ER segment studded with ribosomes; synthesizes and folds proteins destined for membranes or secretion.

Smooth ER

ER segment lacking ribosomes; synthesizes lipids, detoxifies drugs, and stores Ca²⁺.

Ribosome

Macromolecular complex of rRNA and protein that translates mRNA into polypeptides; site of protein synthesis.

Golgi Apparatus

Stack of flattened cisternae that modifies, sorts, and packages ER products into vesicles for transport.

Vacuole

Membrane-bound vesicle for storage, waste breakdown, and maintaining turgor in plant cells.

Lysosome

Acidic, enzyme-filled vesicle that digests macromolecules, old organelles, or pathogens; nicknamed “suicide bag.”

Autophagy

Lysosome-mediated process of degrading the cell’s own damaged organelles or proteins.

Peroxisome

Small oxidative organelle that breaks down fatty acids, detoxifies poisons, and neutralizes reactive oxygen species.

Reactive Oxygen Species (ROS)

Highly reactive oxygen-containing molecules that can damage cellular components; detoxified by peroxisomes.

Centrosome

Microtubule-organizing center containing a pair of centrioles; crucial for spindle formation during mitosis.

Centriole

Cylinder of microtubule triplets within centrosomes that aids in cell division.

Cytoskeleton

Network of protein filaments (microtubules, microfilaments, intermediate filaments) providing structure, transport, and movement.

Mitochondrion

Double-membrane organelle, site of aerobic respiration and ATP generation; called the cell’s powerhouse.

Cristae

Infoldings of the mitochondrial inner membrane that increase surface area for electron transport and ATP synthesis.

Adenosine Triphosphate (ATP)

Main energy currency of the cell; releases energy when its third phosphate is hydrolyzed.

ATP-ADP Cycle

Reversible phosphorylation cycle in which ATP loses a phosphate to become ADP, releasing energy, and is regenerated by cellular respiration.

Cellular Respiration

Metabolic pathway (glycolysis, Krebs cycle, electron transport) that converts glucose and O₂ into ATP, CO₂, and H₂O.

Chloroplast

Plant and algal organelle where photosynthesis converts solar energy into chemical energy (glucose).

Thylakoid

Membranous sac inside chloroplasts containing chlorophyll; site of light reactions.

Granum

Stack of thylakoids within a chloroplast.

Stroma

Protein-rich fluid inside chloroplasts surrounding thylakoids; site of Calvin cycle.

Simple Diffusion

Passive movement of small, non-polar molecules across a membrane down their concentration gradient.

Facilitated Diffusion

Passive transport of molecules across a membrane via channel or carrier proteins.

Active Transport

Energy-requiring movement of substances against their concentration gradient through membrane proteins.

Bulk (Vesicular) Transport

Energy-dependent process (endocytosis or exocytosis) that moves large particles or volumes via vesicles.

Phagocytosis

Form of endocytosis where a cell engulfs large particles or microorganisms, forming a food vacuole.