Chapter 3.1- Prokaryotic Cell Anatomy

DNA

Singular genetic material that is not enclosed within membrane, is circular, and is not associated with histone proteins

Morphology

Appearance of individual cells (shape), maintained by cell wall and cytoskeleton

Arrangement

How cells are grouped together

Coccus

Round cell shape

Single Coccus

One round cell

Diplococci

2 round cells

Streptococci

Chain of round cells

Tetrad Coccus

4 round cells in a square

Sarcina Coccus

8 round cells in a cube

Staphylococci

Clusters of round cells

Bacillus

Rod shaped cells

Single Bacillus

One rod shaped cell

Diplobacilli

Two rod shaped cells

Streptobacilli

Chain of rod shaped cells

Coccobacillus

Squished rod shaped cell

Spiral

Curved shaped cell, all single arrangements

Vibrio

Comma shaped cell

Spirillum

Short, thick rod shaped cell

Spirochete

Thin, long, flexible rod shaped cell

Pleomorphic

Cell that changes shape

Plasmid

Extrachromosomal DNA, replicates independently

Bacteria Phospholipid

Phospholipid with unbranched fatty acid tail + ester linkage + glycerol + phosphate

Archaea Phospholipid

Phospholipid with branched fatty acid tails + ether linkage + glycerol + phosphate

Osmotic Pressure

Pressure caused by differences in solute concentration on opposite sides of a semipermeable membrane

Peptidoglycan

Component of cell wall, repeating subunits of carbs (NAM/NAG) joined by peptide crosslinks (D)

Penicillin Binding Protein

Enzyme that binds the 2 D-alanines in the peptide side chain to create peptide crosslinks, also called PBP and transpeptidase

Gram Positive Cell Wall

Cell wall with single plasma membrane and a thick, multilayered peptidoglycan with teichoic acid strands throughout, has a purple stain

Gram Negative Cell Wall

Cell wall with an inner and outer membrane, a thin peptidoglycan, porin channels, and lipopolysaccharide, has a pink stain

Lipopolysaccharide

Molecule found in outer membrane of G- cell walls, provides structural integrity and protection, made of an o-antigen, core polysaccharide, and a lipid A

Acid-Fast Cell Walls

Cell wall unique to Mycobacterium and certain members of Nocardia, same structure as G+ except it has a waxy outer layer of mycolic acid, doesn’t retain staining well

Pseudomurein

Main component of archaea cell walls

Glycocalyx

Proteins/polysaccharides that surround the cell, resists stains, provides protection, aids attachments, aids biofilm formation, and aids pathogenicity

Capsule

Organized, firmly attached glycocalyx

Slime Layer

Unorganized, loosely attached glycocalyx

Fimbriae/Pili

Thin, hair-like appendages made of pilin, used for attachment, biofilm formation, motility, and DNA transfer

Flagella

Tail/tails that move the cell by rotating, made of flagellin with a hook and a basal body, moves in a series of runs and tumbles

Monotrichous

Single flagella at one pole

Lophotrichous

Multiple flagella at one pole

Amphitrichous

One flagella at each pole

Peritrichous

Even distribution of flagella across surface

Taxis

Movement towards/away from stimuli

Chemotaxis

Movement to/away from chemicals

Phototaxis

Movement to/away from light

Magnetotaxis

Movement along magnetic fields

Axial Filaments

Filament that wraps around spirochetes that allows it to move, similar structure to flagella, also called endoflagella

Endospores

Specialized dormant cells formed by G+ bacteria under stress

Sporulation

Process of endospore formation, also called sporogenesis