Bacteria

The Cell is chemical system that is able to maintain its structure and reproduce. Cells are the fundamental unit of life. All living things are cells or composed of cells.

CELL PROKARYOTIC EUKARYOTIC

EUKARYOTIC Organisms whose cells normally contain a nucleus. PROKARYOTIC Organisms whose cells lack a nucleus and have no membrane-bound organelles.

EUKARYOTIC

PROKARYOTIC

The bacteria (singular bacterium) are amongst the smallest organisms. They are most primitive, simple, unicellular and microscopic organisms. Bacteria occur almost everywhere : in air, water, soil and inside other organisms

Forms of bacteria Bacilli Spirilla Vibrios Cocci

Classification of Bacteria Classification is based on stainability with the Gram stain 1-Gram positive bacteria 2-Gram negative bacteria

Gram-negative Gram-positive property 10 nm 20-80 nm Thickness of wall 2 1 Number of layersin wall 10-20% >50% Peptidoglycan content - + Teichoic acid in wall 58% 0-3% Lipid and lipoprotein content 9% 0% Protein content 13% Lipopolysaccharide Less sensitive Yes Sensitive to pencillin Weakly Digested by lysozyme