micro basics

• Half the size of rickettsia
• Can not be see with light microscope

• Smallest of bacteria
• No cell wall

• (“Blue-green algae”)
• share structural andbiochemical properties of bacteria
• Have light trapping

• Once considered plants, but plants do not have chitin
• Do not employ photosynthesis
• use performed organic matter from environment: very resilient, important decomposer's of organic material
• Eukaryotes that are divided into two major branches – they exhibit diamorphic growth (adaptability)
• :yeasts – unicellular
• :molds – long chains of cells

• Plant-like
• use photosynthesis
• differ structurally from mosses, ferns, and seed plants
• two types
• :diatoms(eukaryotic) – important food source in ocean (whales filter water to eat these
• :dinoflagellates – photosynthetic eukaryotescomposed of amoebae in hard shells

• no observable activity except replication
• only function inside living cells
• observed with electron microscope only
• consist basically of nucleic acid and protein
• nucleic acid packaged inside protein: released when virus penetrates cell
• takes over host cell’s structures and enzymes to replicate (cell often destroyed)
• as more cells involved, tissue disintegration occurs (common to all viral diseases)

sphere shape

• : diplococci and streptococci
• : tetrad
• : sarcina
• : staphylococc

• :rod shape
• Singlebacillus
• Diplobacilli
• Streptobacilli
• Coccobacillus

• Vibrio
• Spirillum-relatively thick
• Spirochete-more waves than spirillum and much thinner

• Happens when organism loses their cell wall (for whatever reason)
• Assumes shape based on the influential pressure of their environment

appendages that are short,straight hair-like fibers

transfer genetic material

• (attachment pili)
• adhesion to host tissue

adhearing layer of polysaccharides and small proteins

glycocalyx is thick and tightly bound to the cell

thin, flowing and less tightly bound

• Formed by various rods and cocci but NOT spiral bacteria
• Purpose: Buffer between cell and external environment
• Prevents nutrients from flowing away
• As a capsule or slime layer – inhibits phagocytosis

slime layers and capsule key elements in formation of a series of encased microcolonies of bacteria

• attach to such surfaces as body tissues and Prosthetic devices
• believed that most bacteria within nature live within biofilms

• prevents bacterial cells from rupturing when water pressure inside is greater than outside
• Responsible for shape of cell
• Serves as point of advantage for flagella

• Rotates clockwise until it finds what it is looking for
• Then goes to counterclockwise to move straight ahead
• Reverts back to clockwise rotation when it is looking for something again
• More flagella isn’t always better; the fastest mover happens to have only one flagellum

• (Plasma membrane)
• Nutrients are transported into cell
• Transports waste material out of cell
• Anchors the DNA during replication
• Site for enzymes used in energy metabolism
• Consists of 60% protein and 40% phospholipid

• Proteins(usually in the form of enzymes)
• Carbohydrates
• Lipids
• Nucleic acids
• Salts and inorganic ions

• Center for growth and metabolism
• Various organelles found here
• May have plasmids (small closed loops of DNA that are independent of the cell’s chromosome)
• :Relatively few genes
• :Carry genes for toxicity and drugresistance

• Gram positive rods such as Bacillus and Clostridium
• Purpose is for survival not reproduction
• (Give the bacteria an escape in harsh conditions by forming a protective wall around DNA while cell dies)

asexual process of replication

• (aka Doubling Time)
• Interval of time until the completion of the next cell division
• helps determine how long it will take before disease symptoms appear

• Psychrophiles: 0-20 C
• Mesophiles:20-40 C
• Thermophiles40-90 C