Prokaryotes & Cell Theory – Lecture Notes

Vocabulary flashcards covering key terms about prokaryotic structure, reproduction, cell theory, and basic biological principles from the lecture notes.

Binary fission

A form of asexual reproduction in which one prokaryotic cell divides into two genetically identical cells, sometimes every 15 minutes.

Scientific theory

An explanation of a natural phenomenon supported by repeated experiments and observations.

Cell theory

States that all living things are made of cells, the cell is the basic structural and functional unit of life, and all cells arise from pre-existing cells through division.

Three domains of life

Bacteria, Archaea, and Eukarya (the latter being more complex than bacteria).

Prokaryote

A unicellular organism lacking a membrane-bound nucleus and organelles; includes Bacteria and Archaea.

Nucleoid

The non-membrane-bound region in a prokaryotic cell where the circular chromosome is tightly clumped.

Plasmid

A small, circular, double-stranded DNA molecule in prokaryotes that carries non-essential genes and replicates independently of the chromosome.

Cytoplasm

The jelly-like interior of a cell (mainly cytosol) where metabolic reactions occur; contains DNA, ribosomes, and other components.

Ribosome

A molecular machine composed of RNA and protein that synthesizes proteins in prokaryotic and eukaryotic cells.

Plasma membrane

The phospholipid bilayer that controls what enters and exits the cell.

Cell wall (prokaryotic)

Rigid layer outside the plasma membrane; often contains peptidoglycan and provides shape and protection.

Peptidoglycan

A polymer of sugars and amino acids that forms a mesh-like layer in many bacterial cell walls.

Capsule

A sticky outer layer some prokaryotes possess; aids in adherence to surfaces and prevents desiccation.

Flagellum

A long, whip-like appendage used by many prokaryotes for movement.

Fimbriae (pili)

Hair-like surface structures that help prokaryotes adhere to surfaces and to each other.

Bacterial shapes

Common forms include rods (bacilli), spheres (cocci), and spirals (spirilla).

Respiration equation

Glucose + O₂ → CO₂ + H₂O + energy (ATP).