Diversity of microbes Flashcards
What were the first forms of life on earth?
Prokaryotes
What were some of the extreme conditions they adapted to?
Heat, high geologic activities, no oxygen, and high mutagenic radiation from the sun.
What are microbial mats?
Multi-layered sheets of prokaryotes that secrete a sticky substance.
What are microbial mats?
Multi-layered sheets of prokaryotes that secrete a sticky substance.
What are stromatolites?
Microbial mats with minerals precipitated out of water.
How did the first prokaryotes get their energy?
They would eat each other, or organic molecules.
What is anaerobic respiration?
Early respiration without oxygen.
When did photosynthesis begin? and through what?
About three billion years ago, through autotrophic organisms.
What happened as a result of photosynthesis?
The phototrophs would produce oxygen via photosynthesis and the environment became enriched with oxygen, paving the way for other life forms.
When did eukaryotic organisms first appear?
Between 2 and 2.5 billion years ago.
Oxygen in the atmosphere led to what?
Ozone, which protects organisms against mutagenic radiation from the sun.
What are extremophiles?
Prokaryotes that can live under extreme conditions.
How are prokaryotes studied?
They are cultured on agar in petri dishes.
Who discovered the prokaryote culture method?
Richard Koch
What are biofilms?
Bacteria that stick together and to a surface by a sticky layer of polysaccharides or proteins.
What’s an example of a biofilm?
Dental plaque
What is capsule?
Sticky mesh around the cell.
What are the three cell shapes of prokaryotes?
Coccus, bacillus, and spiral-shaped.
What are coccus?
Spherical cells.
What are bacillus?
Rod-shaped cells.
What are spiral-shaped cells?
cells shaped like spiral you idiot.
What are the two domains in prokaryotes?
Archaea and bacteria.
What are the two main groups bacteria is divided into?
Gram-positive and gram-negative.
In gram-positive bacteria, the wall is?
Thick!
In gram-negative bacteria, the wall is?
Thin!
What are porins?
Proteins in the cell membrane of gram-negative bacteria that allow substances to enter the outer membrane.
Where is chlorophyll located?
In the membrane of the cell.
What is nitrogen fixation?
The transformation of gaseous nitrogen into ammonia NH3 and ammonium NH4+
What is ammonification?
Release of ammonia from decomposition.
What is nitrification?
Conversion of ammonium to nitrite and nitrate.
What is dentrification?
Reduction of nitrate to N2
