Chapter_4_Cell_Structures

Prokaryote

A unicellular organism that lacks a nucleus and membrane-bound organelles, typically classified into two domains: Bacteria and Archaea.

Eukaryote

An organism with complex cells that contain a nucleus and membrane-bound organelles; can be unicellular or multicellular.

Binary fission

The process by which prokaryotic cells divide, resulting in two identical daughter cells.

Capsule

A protective outer layer of some prokaryotic cells that helps them evade the host's immune system.

Cell wall

The rigid structure that surrounds the plasma membrane in some cells, providing support and protection.

Plasma membrane

The semi-permeable membrane that encloses a cell, controlling the movement of substances in and out.

Cytoplasm

The gel-like substance within a cell, between the plasma membrane and nuclear envelope, where many metabolic reactions occur.

Ribosomes

Molecular machines within the cell that synthesize proteins.

Nucleus

An organelle that houses the cell's genetic material (DNA) in eukaryotic cells.

Endoplasmic reticulum

An organelle involved in the synthesis, folding, modification, and transport of proteins and lipids.

Golgi apparatus

An organelle responsible for modifying, sorting, and packaging proteins and lipids for transport.

Lysosomes

Organelles that contain digestive enzymes to break down waste materials and cellular debris.

Vesicles

Small membrane-bound sacs that transport substances within and outside the cell.

Chloroplast

An organelle in plant cells responsible for photosynthesis, converting light energy into chemical energy.

Mitochondria

The powerhouse of the cell, organelles which produce adenosine triphosphate (ATP) through cellular respiration.

Cytoskeleton

A network of protein fibers in the cytoplasm that provides structural support and aids in cell movement.

Peroxisomes

Small organelles not part of the endomembrane system, involved in fatty acid metabolism and detoxification.

Eubacteria

A domain of prokaryotic organisms known for their diverse metabolic abilities.

Archaebacteria

Prokaryotic organisms that often live in extreme environments and have unique biochemical and genetic features.

Microtubules

Filaments that provide structural support, shape, and transport within eukaryotic cells.

Plasmid

A small, circular DNA molecule found in prokaryotes that can replicate independently of chromosomal DNA.

Phospholipid bilayer

The fundamental structure of the plasma membrane, composed of two layers of phospholipids.

Nucleoid region

The area in prokaryotic cells where the circular DNA resides, not separated by a membrane.

Asexual reproduction

A mode of reproduction that does not involve the fusion of gametes, commonly through processes like binary fission in prokaryotes.