Chp 17 Microbial Life Flashcards
How are bacteria essential to human life?
Makes vitamins and prevents fungal growth
What is a photoautotroph?
harnesses light energy to drive synth of organic compound from CO2.
Unlike eukaryotes, prokaryotes are able to metabolize most forms of nitrogen. Whats dinitrfication?
conversion of NO2 or NO3 to atmospheric gas
what is an obligate aerobe?
Use oxygen for cell resp. and cannot grow without it
whats a facultative anaerobe?
will use oxygen if present, but can grow by fermentation
what is an obligate anaerobe?
oxygen is poison.
A bacterium living in an underground septic tank thriveds by absorbing organic compounds from decomposing wastes. what is it?
Chemoheterotroph
How to prokaryotes reprouce?
Binary Fission: chromosome replication, splitting of cell into two daughter cells
What is a flagella?
Rotating whip like structure aids in locomotion
what is pili?
hair like appendage aids in clinging to surfaces. common in gram negative. longer and thinner than flagellum. used for bacterial conjugation
What is an endospore?
thick protective coat used in extreme conditions. cell is metabolically inactive
What are the characteristics of gram negative bacteria?
Resistant to antibiotics more than gram positive because of the outer membrane- which is unique to gram negative
explain chemotaxis
organisms direct their movement according to chemicals in environment to swim towards food or away from poisons
whats phototaxis
moves in response to light stimulus
magnetotaxis?
organisms contain internal structures called magnetosomes which orient to earths magnetic field.
