GRAM-POSITIVE and GRAM-NEGATIVE

	Gram-negative Bacteria	Gram-positive Bacteria
Gram reaction:	Can be decolourized to accept counter stain (Safranin or Fuchsine); stain red or pink, they don't retain the Gram stain when washed with absolute alcohol and acetone.	Retain crystal violet dye and stain dark violet or purple, they remain coloured blue or purple with gram stain when washed with absolute alcohol and water.
Peptidoglycan layer:	Thin (single-layered)	Thick (multilayered)
Teichoic acids:	Absent	Present in many
Periplasmic space:	present	Absent
Outer membrane:	Present	Absent
Lipopolysaccharide (LPS) content:	High	Virtually none
Lipid and lipoprotein content:	High (due to presence of outer membrane)	Low (acid-fast bacteria have lipids linked to peptidoglycan)
Flagellar structure:	4 rings in basal body	2 rings in basal body
Toxins produced:	Primarily Endotoxins	Primarily Exotoxins
Resistance to physical disruption:	High	Low
Inhibition by basic dyes:	High	Low
Susceptibility to anionic detergents:	High	Low
Resistance to sodium azide:	High	Low
Resistance to drying:	High	Low
Cell wall composition:	The cell wall is 70-120 Armstrong thick two layered.The lipid content is 20-30% (High), whereas Murein content is 10-20% (Low).	The cell wall is 100-120 Armstrong thick, single layered. The Lipid content of the cell wall is low , whereas Murein content is 70-80% (Higher).
Mesosome:	Mesosome is less prominent.	Mesosome is more prominent.
Antibiotic Resistance:	More Resistant to antibiotics.	More Susceptible to antibiotics

PROKARYOTIC - EUKARYOTIC CELL COMPARISION

	Eukaryotic Cell	Prokaryotic Cell
Nucleus:	Present	Absent
Number of chromosomes:	More than one	One--but not true chromosome: Plasmids
Cell Type:	Usually multicellular	Usually unicellular (some cyanobacteria may be multicellular)
True Membrane bound Nucleus:	Present	Absent
Example:	Animals and Plants	Bacteria and Archaea
Genetic Recombination:	Meiosis and fusion of gametes	Partial, undirectional transfers DNA
Lysosomes and peroxisomes:	Present	Absent
Microtubules:	Present	Absent or rare
Endoplasmic reticulum:	Present	Absent
Mitochondria:	Present	Absent
Cytoskeleton:	Present	May be absent
DNA wrapping on proteins.:	Eukaryotes wrap their DNA around proteins called histones.	Multiple proteins act together to fold and condense prokaryotic DNA. Folded DNA is then organized into a variety of conformations that are supercoiled and wound around tetramers of the HU protein.
Ribosomes:	larger	smaller
Golgi apparatus:	Present	Absent
Chloroplasts:	Present (in plants)	Absent; chlorophyll scattered in the cytoplasm
Flagella:	Microscopic in size; membrane bound; usually arranged as nine doublets surrounding two singlets	Submicroscopic in size, composed of only one fiber
Permeability of Nuclear Membrane:	Selective	not present
Plasma membrane with steroid:	Yes	Usually no
Cell wall:	Only in plant cells and fungi (chemically simpler)	Usually chemically complexed
Cell size:	10-100um	1-10um

ANIMAL - PLANT CELL COMPARISION

	Animal Cell	Plant Cell
Cell wall:	Absent	Present (made of cellulose)
Shape:	Round (irregular shape)	Rectangular (fixed shape)
Vacuole:	One or more small vacuoles (much smaller than plant cells).	One, large central vacuole taking up 90% of cell volume.
Centrioles:	Present in all animal cells	Only present in lower plant forms.
Chloroplast:	Animal cells don't have chloroplasts	Plant cells have chloroplasts because they make their own food
Cytoplasm:	Present	Present
Endoplasmic Reticulum (Smooth and Rough):	Present	Present
Ribosomes:	Present	Present
Mitochondria:	Present	Present
Plastids:	Absent	Present
Golgi Apparatus:	Present	Present
Plasma Membrane:	only cell membrane	cell wall and a cell membrane
Microtubules/ Microfilaments:	Present	Present
Flagella:	May be found in some cells	May be found in some cells
Lysosomes:	Lysosomes occur in cytoplasm.	Lysosomes usually not evident.
Nucleus:	Present	Present
Cilia:	Present	It is very rare