Bio Chapter 4

Cell

The smallest unit of life.

Microscope

An instrument used to study cells that cannot be seen with the naked eye.

Unified Cell Theory

States that all organisms are made of one or more cells, the cell is the basic unit of life, and new cells arise from existing cells.

Prokaryotes

Single-celled organisms of the domains Bacteria and Archaea.

Peptidoglycan

The primary component of most prokaryotic cell walls.

Plasma Membrane

A lipid bilayer that surrounds the cell, regulating what enters and exits.

Eukaryotic Cell

A type of cell that is typically larger than prokaryotic cells and has a true nucleus and membrane-bound organelles.

Nucleus

The membrane-bound organelle that contains the cell's DNA.

Ribosomes

Cellular structures that perform protein synthesis.

Mitochondria

Organelles that participate in cellular respiration and produce ATP.

Peroxisomes

Organelles that hydrolyze fatty acids, amino acids, and some toxins.

Vesicles

Small membrane-bound compartments for storage and transport within the cell.

Lysosomes

Digestive organelles in animal cells that break down macromolecules.

Chloroplasts

Organelles where photosynthesis takes place in plant cells.

Golgi Apparatus

Cellular component that modifies, packages, tags, and transports proteins and lipids.

Endomembrane System

A system that includes the nuclear envelope, lysosomes, vesicles, ER, Golgi apparatus, and plasma membrane.

Cytoskeleton

A network of protein elements that provide structure and shape, and facilitate movement within the cell.

Microfilaments

The narrowest type of protein element in the cytoskeleton, associated with myosin.

Desmosomes

Cell structures that act like spot welds, anchoring cells together.

Tight Junctions

Watertight seals between adjacent cells.

Plasmodesmata

Channels that connect adjacent plant cells and facilitate communication.

Gap Junctions

Channels that connect adjacent animal cells, allowing for communication.

Central Vacuole

A large storage compartment in plant cells that can expand without producing more cytoplasm.