Microbiology Lesson 5 Flashcards
A group of microbes that are single celled prokaryotes such as bacteria and archaea. It is a unicellular that does not contain a membrane bound nucleus or organelles.
Prokaryotes
a Region of cytoplasm where prokaryote’s genome (DNA) is located. Usually a singular, circular chromosome.
Nucleoid
Small extra piece of chromosome/genetic material.
Plasmid
cytoplasm is also known as _______?
proto-plasm
It is a gel-like matrix of water, enzymes, nutrients, wastes, and gases and contains cell structure.
Cytoplasm
Bacteria’s way of storing nutrients & Staining of some granules aids identification.
Granules
Cellular “scaffolding” or “skeleton” within the cytoplasm. A major advance in prokaryotic cell biology over the last decade has been the discovery of the prokaryotic cytoskeleton.
Cytoskeleton
Found within the cytoplasm or attached to plasma membrane; Made of protein & rRNA; Composed of two subunits; Cell may contain thousands.
Ribosomes
Separates the cell from its environment.
Phospholipid molecules oriented so that hydrophilic water-loving heads directed outward and hydrophobic water-hating tails directed inward.
Plasma Membrane
Is the diffusion of water across a semi-permeable membrane.
Osmosis
equal concentrations of a solute inside and outside of cell.
Isotonic
a higher concentration of solute.
Hypertonic
a lower concentration of solute.
Hypotonic
2 major classes of the bacterial world
Gram positive (+) & Gram negative (-)
A huge polymer of interlocking chains of alternating monomers & Provides rigid support while freely permeable to solutes.
Peptidoglycan
Backbone of peptidoglycan molecule composed of two amino sugar derivatives of glucose. The “glycan” part of peptidoglycan are ________?
N-acetylglucosamine (NAG) & N-acetylmuramic acid (NAM)
NAG / NAM strands are
connected by interlocking peptide bridges.
The “peptid part of peptidoglycan.
Some bacteria have an additional layer outside of the cell wall called the ______?
glycocalyx
2 forms of glycocalyx?
Slime Layer & Capsule
Glycoproteins loosely associated with the cell wall & Slime layer causes bacteria to adhere to solid surfaces and helps prevent the cell from drying out.
Slime Layer
The slime layer of Gram+ Streptococcus mutans allows it to accumulate on tooth enamel (yuck mouth and one of the causes of cavities).
Streptococcus
Polysaccharides firmly attached to the cell wall.
Capsule
Dormant, tough, non-reproductive structure produced by small number of bacteria.
Resistant to radiation, desiccation, lysozyme, temperature, starvation, and chemical disinfectants.
Endospores
obligate or facultative anaerobes,
endospore producers
bacillus-shaped
Gram Positive
