Give examples of structural arrangements for prokaryotic cells.
single or individual
pairs - diplo
chains - strep
clusters - staphylo
tetrads - group of 4 cells
Sarcinae - group of 8 cells
single molecule of DNA
peptidoglycan in cell wall
DNA discrete packages (chromosomes)
no peptidoglycan in cell wall
What are the four main functions of the bacteria cell wall?
Maintains cell shape
Protects cell from adverse conditions
Protects cell from osmotic lysis
Provides anchorage for flagella
Give three reasons why the bacterial cell wall is clinicaly important.
It's ability to cause disease
Site of action of some antibiotics
Chemical composition helps in bacterial identification
What are three things that make up the bacterial cell wall?
What key items make up the Gram Positive cell wall?
Many layers of peptidoglycan (thick and rigid) 20 layers
What is are the functions of teichoic acid?
Bind and regulate the movement of positive ions
prevents cell lysis during growth
What are the two items that a gram negative cell wall is composed of?
Thin layer of peptidoglycan in periplasm
What is the gram negative cell wall outermembrane composed of?
What are two types of lipopolysaccharides that make up the gram negative cell wall?
What are 4 features of a glycocalyx?
Viscous gelatinous consistence (sticky)
Made of polsaccharide or polypeptide
Made inside and excreted outside the CW
Name the two types of glycocalyx.
What are 4 functions of the glycocalyx?
Protects organism from phagocytosis
allows adherence to surfaces
may be used as nutrient by some bacteria
protects against dehydration
What is flagella?
Long filamentous appendages providing motility on their own.
Name the four types of flagellar arrangements.
Monotrichous - single, polar flagellum
Amphitrichous - tuft at each end
Lophotrichous - 2 or more flagella at one pole
Peritrichous - around entire cell
What is the purpose of axial filaments, and how do they work?
Bundles of fibrin arising at the ends of the cell beneath the outer sheat
Wrap around the whole cell
rotation of outer sheath propels the cell in spiral motion
What are cells that have axial filaments called?
What is fimbria composed of and what is it's overall function?
Fimbriae is composed of hairlike appendages made of pilin(protein).
Fimbriae's overall function is attachment (adherence to surfaces)
What is the function of pilus?
Used to join bacterial cells to transfer DNA
What are two features of O polysaccharide?
Is antigenic (A substance that when introduced into the body stimulates the production of an antibody)
Basis for serotyping
What are two features of Lipid A?
Releases endotoxins that cause fever and shock.
What are traits of an acid fast cell wall?
Gram positive cell wall
Waxy layer which is more resistant to antibiotics and is composed of glycolipids and fatty acids
Identify the cell structure:
Made up of phospholipid bilayer with proteins
What are the two main functions of the plasma membrane?
Metabolic functions (enzymes)
*synthesis of ATP
*photosynthesis (in plant cell)
What are 3 agents that affect the plasma membrane?
What is the cytoplasm and what is it composed of?
Substance inside the plasma membrane
Houses the organelles
Composed of 80% water with proteins, CHO, lipids etc.
What is number 2 pointing at:
No need for survival
Provide advantages such as resistance to antibiotics and toxins
Name this organelle:
Site of protein synthesis
Composed of 2 subunits: 50s & 30s = 70s
Each subunit consists of rRNA and proteins
Target for certain antibiotics
When the evironmental conditions become adverse some bacteria create these.
What is the function of cilia?
Moving substances along the surface of the cell and locomotion.
What are the 3 functions of the cytoplasmic membrance? (eukaryotic)
Passive and active transport processes for the movement of substances
Endocytosis to include phagocytosis and pincocytosis
What is the nucleus composed of?
Majority of DNA
What are the different types of bacterial stains?
Lactophenal Cotton blue
What are the four components that make up the gram stain?
What are the 3 major needs for microbial growth?
What are the two main catergories in microbial growth?
physical - temperature, pH
chemical - H2O, C & N
What are the 3 primary groups based on temperature range?
Psychophiles - cold loving - 10 – 20◦
Mesophiles - moderate temperature loving - 20 – 40◦
Thermophiles - heat loving - 50 – 60◦
Most bacteria grow best in what pH range?
6.5 - 7.5
What pH range do yeasts and molds prefer?
5 - 6
The force with which a solvent moves from an area of lower solute concentration to a solution of higher solute concentration
Shrinkage of the cell in hypertonic solutions.
Require high salt concentration for growth
Do not require high salt concentration but can tolerate up to 2%
What is needed for all organic compounds in cell
What are other chemical requirements needed for microbial growth aside from carbon?
Nitrogen, sulfure, phosphorus, oxygen and trace elements of iron, copper etc.
How is oxygen handled by cells?
combining O2 with H atoms that were removed from organic compounds to form H2O
Process yeilds energy
Oxygen required for growth
Can grow with or without oxygen
Unable to use molecular oxygen
Tolerate to oxygen but do not use it for growth
Decreased oxygen concentration
What are 4 examples of essential compounds the organism is not able to synthesize on it's own?
What are 3 bacterial culture requirements?
proper culture media to support growth of desired microorganisms
What are 4 types of media?
Nutritive - basic components to support most bacterial growth
Enriched - extra nutrients added that encourages growth
Selective - inhibits growth of unwanted organisms through, salts, dyes, other chemicals
Differential - contain compounds that allow differentiation based on metabolic differences
What are four types of bacterial division?
Binary fission - most
Time for a cell to divide and it's population to double
Little or no cell division
growth rate = death rate
Death is greater than growth
Death phase or Log decline
What are 4 methods for measuring microbial growth?
density measurment (turbidity)
direct microscopic count
What is a bacterial colony?
Population of cells arising from a single bacterium
Visible with the naked eye on culture medium
Sum of all chemical reactions that occur in an organism.
Either require or release enegery
What are the two classes of chemical reactions?
Identify the chemical reaction class:
breakdown complex organic compounds
usually hydrolytic reactions
Identify the chemical reaction class:
Reactions that require (E) to create new bonds
Synthesis of complex organic compounds
involve dehydration rxns
generate materials for cell growth
The following steps are included in what process:
Bacteriophage attaches to bacterial cell wall
Injects DNA into cell
Synthesizes new phage DNA and protein coats
Donor cell lysed and phage released
Phage infects new bacterial cell
Donor bacterial DNA recombines with reipient
Organisms that colonize a host with causing disease
Organism that does not normally cause disease but can become pathogenic under certain conditions
A disease causing organism
Manner in which a disease develops
Ability of organism to cause disease
Degree of pathogenicity
disease constantly present in a certain population
Disease aquired by many people in a given area in a short time
Incidence of a specific disease
# of deaths associated with a specific disease
Organismm that lives at the expense of the host
Organism that benefits from the host
Organism that has a neutral affect on the host
host infected with a pathogenic organism with manifesting disease
infection aquired during hospitilization.
Aquired as an infant
competes with pathogens for nutrient space
sythesize nutrients in intestinal tract
contributes to overall health of the host
use CO2 also called lithotrophs
Feed on others
Require an organic C source
also called organotrophs
Nutrients from dead organic matter.
Gene has gone through translation and produced a functional protein