Chapter 4 - Prokaryotic Cell Structure & Function I Flashcards
The prokaryotic cell is ______ and structurally ____________.
Small
Structurally simple
You must be familiar with all of the structures listed in the following image.
Identify the labeled parts of the basic prokaryotic cell.

A. Pilus
B. Ribosome
BB. Storage granule
C. Flagellum
E. Cytoplasm
F. Cell membrane
G. Murein layer
GG. Outer membrane
T. Nucleoid
Prokaryotic organisms are in many ways the dominant life on earth. In terms of total protoplasmic volume, they make up about ___%.
90%
Why are prokaryotic organisms so successful from an evolutionary perspective?
They have very simple cell structures
What is the typical volume of a prokaryotic cell?
1 µm3
Structural simplicity does not mean ____________ simplicity.
Molecular simplicity
There is a range of sizes for prokaryotic cells. What are the ranges?
0.25 µm to 120 µm in diameter
Most prokaryotes are unicellular. True or false?
True
What are the three common cell shapes of prokaryotes?
- Cylindrical rods (bacillus)
- Spheres (cocci)
- Helical (spirilla)
Some prokaryotes are multicellular and are commonly _________________, made of a chain of identical cells attached end to end. Some are __________, meaning they are branching tubes of cytoplasm contained within walls.
Filamentous
Mycelial
Multicellular prokaryotes generally lack cell differentation. If they do, they usually are ____________, which merely have a different function, or in the case of cyanobacteria, _______________, which fix nitrogen and have a different metabolism.
Spores
Heterocysts
True of false: almost all prokaryotic cells have a cell envelope.
True
True or false: cell envelope structure and chemistry are the same among different groups of prokaryotes.
False - cell envelope strucutre and chemistry can differ among different groups of prokaryotes
True or false: the cell envelope is composed of a single layer.
False. The cell envelope can be a single homogeneous layer or a complex, multilayered structure.
What is the difference between a cell envelope and a cell wall?
The cell envelope comprizes the cell membrane, the cell wall and an outer membrane if present
How do prokaryotic cells protect themselves against osmotic lysis?
Via a cell envelope
Why do prokaryotic cells require protection against osmotic lysis?
Most of them live in environments in which solute concentration is less than their highly concentrated cytoplasm
Why strategy do prokaryotic cells use to protect against osmotic lysis?
The strategy is to contain the cell’s turgor pressure with a layer external to the cell membrane that resists expansion of the cell volume
Who developed the Gram stain process?
Hans Christian Gram in 1884
What is the Gram stain useful for?
Distinguishing some prokaryotic envelopes from each other
Outline the general steps of the Gram stain process.
- Stain with crystal violet (purple)
- Add iodine
- Add decolorizer, either ethanol or acetone
- Stain with safranin (pink)

Gram-positive cells stain _______________.
Purple
Gram-negative cells stain ___________.
Pink






