Prokaryotic and Eukaryotic Cells

These flashcards cover key terms and concepts related to the structure and function of prokaryotic and eukaryotic cells, including definitions of important terms associated with cell biology.

Prokaryotic Cells

Cells that do not have a membrane-bound nucleus and are typically unicellular.

Eukaryotic Cells

Cells that contain a membrane-bound nucleus and organelles.

Biogenesis

The theory that new cells arise only from preexisting cells.

Spontaneous Generation

The discredited theory that living organisms can form from nonliving matter.

Nucleoid

The region within a prokaryotic cell where the DNA is located, not enclosed by a membrane.

Plasmid

A small, circular piece of DNA that can replicate independently of chromosomal DNA.

Ribosome

The cellular structure responsible for protein synthesis, composed of RNA and proteins.

Endoplasmic Reticulum (ER)

An organelle in eukaryotic cells involved in protein and lipid synthesis.

Cell Membrane

The semi-permeable barrier that surrounds the cell, regulating the movement of substances in and out.

Cell Wall

A rigid layer that provides structural support and protection to prokaryotic cells.

Chemotaxis

The movement of an organism in response to a chemical stimulus.

Flagella

Long, whip-like structures that aid in bacterial locomotion.

Fimbriae

Short hair-like projections on the surface of bacteria that help them attach to surfaces.

Glycocalyx

A sticky outer layer that surrounds bacterial cells, helping them evade the immune system.

Gram-positive Bacteria

Bacteria that have a thick peptidoglycan cell wall, retaining the crystal violet stain used in Gram staining.

Gram-negative Bacteria

Bacteria that have a thin peptidoglycan layer and an outer membrane, not retaining the crystal violet stain.

Endotoxin

A component of the outer membrane of gram-negative bacteria that can cause systemic effects when released into the bloodstream.

Exotoxin

A toxic substance secreted by bacteria into their surrounding environment.

Biofilm

A structured community of bacteria encased in a matrix that adheres to surfaces.

Selective Permeability

The ability of the cell membrane to allow certain substances to pass through while blocking others.

Facilitated Diffusion

The process of passive transport of molecules across the cell membrane via specific transmembrane proteins.

Active Transport

The movement of molecules across a cell membrane using energy, usually against a concentration gradient.

Oligosaccharides

Short chains of sugar molecules that are part of the structure of gram-negative bacteria's outer membrane.

Peptidoglycan

A polymer that makes up the cell wall of bacteria, providing structural integrity.