bio 203

prokaryotic cell characteristics

• found in bacteria and archaea

• one circular chromosome without a membrane

• no histones or organelles

• petidoglycan cell walls

• binary fission

characteristics of life

• heredity

• reproduction

• growth

• development

• metabolism

• responsiveness

• transport

essential prokaryotic structures

• cell membrane

• cytoplasm

• ribosomes

• at least one chromosome

cytoskeleton

internal network of protein polymers associated with cell walls; help with cell division, protein localization, and cell shape

proteins in cytoskeleton

• FtsZ (cell division)/ tubulin

• MreB (cell shape)/ actin

• Crescentin (cell shape)/ filament proteins

ribosomes

• site of protein synthesis

• made of 60% protein and 40% RNA

nucleioid characteristics

• not membrane bound

• location of chromosome

Plasmid DNA

• replicate autonomously

• used in genetic engineering

episomes definition

integrate into chromosome

curing definition

loss of plasmid

types of plasmid DNA

• resistance factor

• bacteriocins

• col

• virulence

• metabolic

• conjugative

peptidoglycan structure

• meshlike polymer composed of identical subunits

• contains amino acids

• chains are crosslinked by peptides

gram-positive cell walls

• made of peptidoglycan

• has teichoic acids (for cell wall and division)

  • has periplasmic space secreting exoenzymes

gram-negative cell walls

• have a wall of peptidoglycan and outer membrane

• outer membrane made of lipids, lipoproteins, and lipopolysaccharides

  • periplasmic space makes up 20-40% of cell volume

lipopolysaccharides

• consists of lipid a, core polysaccharide, o antigen

  • important for protection, negative charge, stabilizes membrane structure, and endotoxins

osmotic lysis

movement of water into cell causes swelling and lysis

evidence of cell wall protection

• lysozyme breaks n bonds

• penicillin inhibits peptidoglycan synthesis

protoplast

cell lacking wallsp

spheroplast

cell with cell wall

appendages for motility

flagella and axial filaments

appendages for attachment

fimbriae and pili

glycocalyx purpose

surface coating

s-layer

• consists of a protein linked together

• distressed layer (made in distress)

glycocalyx

• repeating polysaccharides or proteins

• helps bacteria stick to surfaces

• capsules made of polysaccharides

• slime layers easily removed

flagella

made of filament, hook, basal body

endospores are resistant because of:

• calcium

• acid-soluble, dna-binding proteins

• dehydrated core

• spore coat

• dna repair enzymes