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LFCC Bio 150
Chapter 4
18
Microbiology
Not Applicable
09/12/2010

Additional Microbiology Flashcards

 


 

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Term
Prokaryotic
Definition
no nucleus, lack most organelles, are single cells
Term
Eukaryotic
Definition
nucleated, larger, have organelles, single & multicellular
Term
Prokaryotic cell arrangement
Definition
cell division along one plane:
-cells in pairs = diplo
-cells in chains = strepto
- cells in grapelike clusters = staphylo
-cell division occurs by binary fission, not mitosis or meiosis
Term
Bacterial cells consist of the following
Definition
1. A cell membrane, usually surrounded by a cell wall
2. An internal cytoplasm with ribosomes, a nuclear region [nucleoid], and sometimes vesicles/vacuoles [storage].
3. External structures: capsule/slime layer, flagella/cilia, and pili
Term
Cell Wall Properties
Definition
-Maintains ther characteristic shape of the cell
- prevents cell from bursting when fluids flow into cell [osmosis]
- Very porous, not responsible for selective permeability
Term
Components of Cell Walls
Definition
1. Peptidoglycan - most important component in bacterial cell walls.
*Can be thought of as one huge covalently linked polymer, looks like 3D chain-linked fence.
2. Teichoic acid molecules project out of the cell wall in Gram-positive (G+) bacteria.
G+ bacteria have a thick cell wall
Term
Periplasmic Space
Definition
Contains digestive enzymes and transport proteins.
-Food and potentially harmful substances are digested then transported into the cytoplasm.
Term
Lipoproteins
Definition
lipid + protein.
- usually found in G- bacteria.
Term
Lipopolycassharides [endotoxin]
Definition
pieces of the membrane are released when cells die (lyse), & during cell division.
- Causes fever and dialates blood vessels [causing low blood pressure]
*Antibiotics given late in an infection may cause a worsening of symptions, even death.
Term
Gram Positive Bacteria
Definition
-Up to 90% Peptidoglycan [PTG]
- Lack an outer membrane and periplasmic space
-Thick cell wall holds Gram stain, leaving cells purple [crystal violet]
Term
Gram Negative Bacteria
Definition
- Up to 20% PTG
- Have outer membrane and periplasmic space
-Thin cell wall doesn't hold crystam violet.
Term
Bacteria that do not have cell walls
Definition
1. Mycoplasma
2. L-forms
Term
Lysozyme
Definition
enzyme found in tears, digests PTG and is primary defense against bacteria in human eye
Term
Phospholipid bylayer
Definition
-hydrophilic head [polar]
-hydrophobic tail [nonpolar]
Term
Cell Recognition Protein
Definition
Act as receptors for chemicals
Term
Carrier Protein
Definition
Selectively transport materials across cell membrane
Term
Enzymatic Protein
Definition
Help synthesize cell wall, replicate DNA, and generate ATP
Term
Channel Protein
Definition
Protein form channels through cell membrane
2 major classes:
1. Lead-open all teh time
2. Gated-open in response to specific environmental stimuli
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