Prokaryotic cells share a basic set of life-supporting structures, yet vary in shape and organization. This lesson introduces the features that distinguish prokaryotes and explains how cell shape and the cell wall relate to water movement.
All cells have cytoplasm, a water-based substance containing chemicals needed for growth, enclosed by a plasma membrane. Cells also contain genetic material organized into chromosomes and ribosomes, which synthesize proteins.
All flashcards
What basic structures are present in all cells?
All cells have cytoplasm enclosed by a plasma membrane, genetic material organized into chromosomes, and ribosomes for protein synthesis.
What is the main distinction between prokaryotic and eukaryotic cells?
Prokaryotes lack a membrane-bound nucleus and generally have a chromosome in a nucleoid. Eukaryotes have a membrane-bound nucleus containing chromosomes.
How do morphology and arrangement differ?
Morphology is the shape of an individual cell. Arrangement is the way cells are grouped after division.
What is osmosis?
Osmosis is the net movement of water across a semipermeable membrane toward the side with the higher solute concentration.
How does a cell wall help a prokaryote?
The wall supports cell shape and protects against osmotic pressure, helping the cell resist swelling and lysis.
Quiz questions
Which description best distinguishes a plasmid from a typical prokaryotic chromosome?Answer: A plasmid is separate DNA that can carry useful genes.
Which membrane feature is characteristic of Archaea compared with Bacteria?Answer: Archaeal lipids have branched chains joined by ether linkages.
Which feature is characteristic of a gram-negative bacterial envelope?Answer: A thin peptidoglycan layer and an outer membrane containing LPS.
What is the primary role of a bacterial endospore?Answer: To protect the bacterial genome during unfavorable conditions.
How does an attractant affect the movement pattern of many bacteria?Answer: It lengthens runs and shortens tumbles on average.
Based on Microbiology by Nina Parker, Mark Schneegurt, Anh-Hue Thi Tu, Philip Lister, Brian M. Forster (OpenStax), licensed CC BY 4.0. Adapted into a summary, flashcards and quizzes.