Cells: The Fundamental Unit of Life

Vocabulary flashcards summarizing key terms and definitions related to cell biology and the fundamental unit of life.

Cell

The simplest collection of matter that can be alive; can be single cellular or multicellular.

Eukaryotic Cells

Cells with internal membranes that compartmentalize functions; include protists, fungi, animals, and plants.

Prokaryotic Cells

Cells without a nucleus and membrane-bound organelles; include bacteria and archaea.

Plasma Membrane

A selective barrier that allows sufficient passage of oxygen, nutrients, and waste.

Endomembrane System

A system of membranes that includes the nuclear envelope, endoplasmic reticulum, Golgi apparatus, lysosomes, vacuoles, and plasma membrane.

Rough Endoplasmic Reticulum (Rough ER)

Synthesizes proteins and packages them in vesicles; has bound ribosomes.

Smooth Endoplasmic Reticulum (Smooth ER)

Synthesizes lipids, metabolizes carbohydrates, detoxifies drugs and poisons, and stores calcium ions.

Golgi Apparatus

Flattened membranous sacs that modify, manufacture, and package materials from the endoplasmic reticulum.

Lysosomes

Membranous sacs of hydrolytic enzymes that digest macromolecules and break down worn-out cell parts.

Mitochondria

Organelles that are the sites of cellular respiration, converting chemical energy into ATP.

Chloroplasts

Organelles that capture light energy and are the sites of photosynthesis.

Endosymbiont Theory

Theory that suggests mitochondria and chloroplasts originated as prokaryotic cells engulfed by ancestral eukaryotic cells.

Peroxisomes

Specialized metabolic compartments that remove hydrogens from molecules and convert hydrogen peroxide to water.