Microbiology: Unit 1 Module B Prokaryote structure and function
Biochemical and synthetic activities
The cytoplasmic membrane is the site for ______________ and ______________ activities.
Strephtococcus
The genus _______________ is characteristically seen in pairs (diplococci) and chains.
Tetrads
groups of four
Cell Envelope
-Hans Christian Gram who developed staining technique based upon cell envelopes Two basic types of "typical" cell walls: -Gram Positive -Gram Negative
Pili (sex pili)
A rigid tubular appendage with a specialized function, ex. transfer of genes during bacterial conjugation Found only in gram-negative bacteria
Mycolic acid Mycobacterium and Nocardia
Bacteria that contain __________________ (a long chain fatty acid) have a waxy consistency and are resistant to certain dyes. They require a special stain and are considered "acid fast". Two bacterial genera that are "acid fast" are __________________ and ___________________.
L Forms
Bacterial variants that lose a cell wall at a certain point during the life cycle
Actin Cytoskeleton
Certain bacteria have developed a way to deal with unfavorable living conditions. When nutrients are unavailable, or atmospheric conditions are not favorable, an organism can produce __________________, a small dormant resistant structure. These structures provide a way for the organism to survive, sometimes indefinitely.
Plasmids are "nonessential" pieces of DNA. What kind of information is carried within the plasmids?
Contain information for drug resistance, toxins, enzymes, etc Exist separate from the chromosome, but can be incorporated Duplicated and passed on during reproduction
Spirochete
Flexible, resembles a spring Borrelia burgdorferi; causes Lyme disease
Cell Wall
Gram +: 1 layer, thicker (purple) Gram -: 2 layers, thinner (red/pink)
"O" somatic antigen
Gram negative cell walls contain polysaccharides that give rise to the ______________________ , which can be useful for identification purposes.
Spirillium
Rigid helix Twisted like a corkscrew Spirillium minor; causes rat bite fever
Vibrio
Rod that is gently curved Vibrio cholerae; causes cholera
Ribosome
Site of Protein Synthesis
shape of a cocci
Spherical, ball shaped Variations can be oval, bean-shaped or pointed Staphylococcus, Streptococcus, Micrococcus
What is the definition of sterile as it applies to microbiology?
Sterility can be defined as "the absence of all viable microorganisms."
Sugars Amino Acids Organic Molecules Salt
The cytoplasm (liquid portion) is made up of 70-80% ___________ and acts as a solvent for nutrients.
Gram -
The outer membrane is only found in gram ________________ cell walls.
3 unctions of cell membrane
Transport - passage of nutrients into cell, discharge of wastes Respiration - enzymes for energy reactions Selectively permeable - special mechanisms for transport
Fimbriae
Used for attachment, to stick to each other or surfaces
Flagella
Used for locomotion toward or away from a chemical or light signal Polar: attached at one or both ends of the cell
circular chromosomal DNA
What is the name of the chemical substance that carries the hereditary information of the cell?
Inclusions?
Where do bacteria store food and other nutrients until they are needed?
Monotrichous
a single flagellum
Iodine
acts as the mordant, a substance that will make the dye stain more intensely.
Lipopolysaccharides (LPS)
are found in gram NEGATIVE cell walls.
Teichoic acid and lipoteichoic acid
are found in gram POSITVE cell walls.
Bacteria
are single-celled, prokaryotic microorganisms that exist in abundance in both living hosts and in all areas of the planet (e.g., soil, water). By their nature, they can be either "good" (beneficial) or "bad" (harmful) for the health of plants, humans, and other animals that come into contact with them.
mycoplasma
bacteria that do not have a fixed shape
Glycocalyx
coating of macromolecules to protect the cell
Peritrichous
flagella are dispersed over the surface of the cell
Amphitrichous
flagella at both poles of the cell
How does an endospore cause disease in humans? (hint: what happens if we accidentally ingest them?)
food poisoning
spheroplast
gram-negative that loses cell wall, LESS fragile (retains outer membrane)
protoplast
gram-positive that loses cell wall, very fragile
Clusters
irregular arrangement
Viruses
is acellular (has no cell structure) and requires a living host to survive; it causes illness in its host, which causes an immune response. Infections caused by harmful bacteria can almost always be cured with antibiotics. While some viruses can be vaccinated against, most, such as HIV and the viruses which cause the common cold, are incurable, even if their symptoms can be treated, meaning the living host must have a strong enough immune system to survive the infection.
Bacillus
is an AEROBIC sporeformer (lives in environments with oxygen)
Clostridium
is an ANAEROBIC sporeformer (lives in oxygen-free environments).
Peptidoglycan
is found in both gram positives and gram negatives, and is composed of alternating strands of N-acetyl glucosamine (NAG) and N-acetyl muramic acid (NAM). The adjacent molecules are bound by cross linkages of peptides. Gram +: thicker Gram -: thinner
Slime Layer
loose shield that protects from dehydration and loss of nutrients, adhesion (example attachment to surfaces of teeth)
Diplococci
pairs
Capsule
repeating polysaccharide units an/or proteins, bound more tightly, sticky, makes it difficult for our cells to phagocytize
Lophotrichous
small bunches or tufts of flagella emerging from the same site
how might we use or manipulate the information in plasmids?
tools to clone, transfer, and manipulate genes