Chapter III Prokaryotic Cells Flashcards
Prokaryotes or Eukaryotes
Bacteria, cyanobacteria, archaea
Prokaryotes
Prokaryotes or Eukaryotes
Protozoans, algae, fungi, plants, & animals
Eukaryotes
Prokaryotes or Eukaryotes
Generally 1-10μm in linear dimension
Prokaryotes
Prokaryotes or Eukaryotes
Generally 5-100μm in linear dimension
Eukaryotes
Prokaryotes or Eukaryotes
Anaerobic or aerobic
Prokaryotes
Prokaryotes or Eukaryotes
Aerobic
Eukaryotes
Prokaryotes or Eukaryotes
Few or none; no nucleus
Prokaryotes
Prokaryotes or Eukaryotes
Nucleus, mitochondrion, chloroplast, ER, Golgi
complex, etc. present
Eukaryotes
Prokaryotes or Eukaryotes
Circular DNA in cytoplasm
Prokaryotes
Prokaryotes or Eukaryotes
Linear DNA with noncoding regions in nucleus
Eukaryotes
Prokaryotes or Eukaryotes
RNA and protein synthesized in the same
compartment
Prokaryotes
Prokaryotes or Eukaryotes
RNA in nucleus; protein in cytoplasm
Eukaryotes
Prokaryotes or Eukaryotes
No cytoskeleton
Prokaryotes
Prokaryotes or Eukaryotes
With cytoskeleton
Eukaryotes
Prokaryotes or Eukaryotes
Chromosomes pulled apart by membrane
attachments
Prokaryotes
Prokaryotes or Eukaryotes
Uses cytoskeletal spindle apparatus
Eukaryotes
Prokaryotes or Eukaryotes
Mainly unicellular
Prokaryotes
Prokaryotes or Eukaryotes
Mainly multicellular ,with differentiation in cell types
Eukaryotes
- similar in structure and function to the eukaryotic cell membrane
- consists of membrane proteins and phospholipids
- a flexible, semi-permeable membrane
Prokaryotic Cells
Cell Membrane
• About 80% water proteins (enzymes), carbohydrates, lipids, inorganic ions • Major structures: – Ribosomes – Nucleoid - contains a single long, continuous, and frequently circularly arranged thread of double-stranded DNA called the bacterial chromosome
Prokaryotic Cells
Cytoplasm
• With the exception of mycoplasmas, all bacteria have a
semirigid cell wall
– component: peptidoglycan, a large polymer composed of Nacetylglucosamine and N-acetylmuramic acid
– Gram-positive bacteria have more peptidoglycan account
for their ability to retain the stain in the Gram stain procedure
– Gram-negative bacteria have more lipids in their cell wall
Prokaryotic Cells
Cell Wall
Have more peptidoglycan account
for their ability to retain the stain in the Gram stain procedure
Gram-positive bacteria
Have more lipids in their cell wall
Gram-negative bacteria
_____ stains both Gram-positive
and Gram-negative cells purple
– Iodine as mordant forms large complexes
that cannot escape the cell wall easily
Crystal violet
_____ dehydrates the peptidoglycan
of Gram-positive bacteria, but dissolves
the outer membrane of the Gram - negative so they become colorless
Alcohol
___ colors the Gram-negative cells
red or pink
Safranin
• slimy, gelatinous material
produced by cell membrane and
secreted outside the cell wall
• serves as a reservoir for nutrients
and protects the organism from
changes in the environment
• when the glycocalyx is a tightly bound structure, it is known as a capsule and slime layer when it is a poorly bound structure that flows easily
Glycocalyx
• thread-like, protein appendages used for locomotion • made up of the protein flagellin. • its shape is a 20 nanometer-thick hollow tube • it is helical and has a sharp bend just outside the outer membrane; this "hook" allows the helix to point directly away from the cell.
Flagellum
• can occur at the poles of bacterial cells and they can be evenly distributed over the entire surface of the cell • enables the cells to adhere to surfaces, including those of the other cells; helps the cell to colonize mucus membranes
Fimbriae
• Hair-like structures most often observed on Gram-negative bacteria • Composed of polymerized protein called pilin • They arise from the cytoplasm and extends to cell membrane, cell wall, and capsule (if present) • Two types: adhering pili and sex pilus
Pili (sing., pili)
• Specialized “resting cells” formed by some Gram-positive bacteria such as Clostridium and Bacillus • Formed when nutrients are depleted
Endospores
• process results in the reproduction of a living prokaryotic cell by division into two parts which each have the potential to grow to the size of the original cell
Binary fission
• formation of a new organism by
the protrusion of part of another
organism
Budding
