Micro Final Exam Flashcards
(50 cards)
What is microbiology?
Microbiology is the study of organisms which are usually seen by a microscope, not the unaided eye.
Prokaryotic vs. Eukaryotic
Prokaryotic cells came into existence before the eukaryote. They do not have membrane bound organelles or a nucleus. Eukaryotic cells have a nucleus and membrane bound organelles
Carl Woese
He created Domain, which is used as a classification system. It showed 2 distinct types of groups, Bacteria and Archaea
Prokaryotes
Majority have cell wall with peptidoglycan. Reproduce by binary fission. About 0.3-5 nanometers.
Significance of Cyanobacteria
produces significant amounts of oxygen; photosynthetic
Are virus’ considered organisms
No, they are considered infectious agents
Viroid and Virusoids
Consist of only RNA; no protein coat
Prions
consists only of protein, no DNA or RNA ex: Mad cow disease
Why did RNA exist before DNA?
RNA was first because it could store information and was catalytic and DNA is NOT catalytic, only a storage molecule
The Endosymbiotic Theory
The theory that states that mitochondria and chloroplasts were acquired to the eukaryotic cell by endosymbiosis from a prokaryotic cell.
Antony Van Leeuwenhoek
improved microscopy Increased magnification 50-300x
Who challenged spontaneous generation and what did he do?
Fransesco Redi challenged spontaneous generation and he did this with the meat and maggots experiment
What is Koch’s Postulate?
- Present in every case of the disease. absent in healthy organisms 2. Must be isolated and grown in pure culture 3.Same disease must result upon infection of healthy organism 4.Same microorganism must be isolated again
What are some application of microbiology?
Sewage Treatment Bioremediation (ex. oil) Produce useful products (ex. insulin, ethanol, amino acids, pesticides) Genetic Engineering Food (lactic acid, fermentation reactions)
Rank microorganisms smallest to largest
virus, bacteria, protist, eurkaryote
Resolution
the ability to distinguish between separate objects
Contrast
light intensity difference between a sample and its background
Relationship between oil and glass
They have the refractive index
Wavelengths relation to resolution
Short wavelengths increase resolution because they can fit where longer wavelengths cant
What are stains composed of?
A chromophore Charged salt- negative dye = acidic pH positive dye = basic pH
Which type of dye is used as a negative stain?
Acidic
Differential Stains
Distinguishes between different types of bacteria Gram stain and Acid Fast stain
What makes something Gram+ or Gram-
Gram positive indicates a thick cell wall, the crystal violet and iodine mixture is not able to escape from the thick peptidoglycan layer. The opposite is true for Gram-
What is the composition of the cytoplasmic membrane?
It is made up of a bilayer of phospholipids. It is amphipathic- there is a different chemical feature on both sides. There is also a lipid bilayer with hydrophilic heads and hydrophobic tails