Micrbones And Energy Flow Flashcards
Outline the characteristics of traditional pure culture microbiology
Tens of thousands of microbes cultured and characterised
Mostly identified pathogens or fast growing organisms
Ignores complex interactions and the fact most organisms live in communities (auxotrophs)
Outline “the unseen majority” of natural environments
20-50% of earths biomass is prokaryotes
Most organisms cannot or have not been isolated in pure culture
Identifications ow done using genetic fingerprints
Currently, there are millions of unique 16S rRNA sequences available in database
Majority of these genes are from uncultivated bacteria
Define a population
Individual microbial cells of a species proliferate to form a population
Define a communities
Populations interact/communicate to form communities
What Is microbial ecology
The study of interrelationships among microorganisms and their environment
What is a microbiome
All microorganisms and their genes writhing a particular environment
What is enrichment culture
Providing temperature and chemical conditions in the laboratory that encourage the growth of specific groups of microbes
What is a mesocosm
An experimental system that simulates real life conditions as closely as possible
Outline one process having two potential goals
Harvesting of building blocks
Harvesting of energy
Process can run in reverse. Need energy to both create a bond, and a building block to attach that bond too
Outline reduction oxidation in bacteria
No free moving electrons in cell, would cause large damage, thus they need energy carriers (NAD+, NADP+).
When H is present = good proton/electron donor=will be oxidised
For every action (eg oxidation) there is an equal and opposite reaction (ie reduction)
Outline NADH/NADPH use in bacteria redox reactions
NADH/NADPH serve as intermediates to transfer energy inside cell
NAD+ and NADH facilitate redox reactions without being consumed - they are recycled
Redox reactions are shuttled through NADH/NADPH
Differentiate between autotrophs and heterotrophs
Autotrophs are primary producers, fix CO2, self sufficient, do not require carbon
Heterotrophs are decomposes, need fixed carbon, cannot use CO2 directly, dependant on primary producers
Differentiate between chemotrophs and phototrophs
Chemotrophs use chemical energy from either organic or in organic compounds
Phototrophs use solar energy
How can many microbial species exist in the same environment using the same light resources
Light is the common resource. Competition avoided by tuning their antenna to different wavelengths of light. Each species requires different wavelengths of light thus is avoiding competition
How do oxygen dependant organisms live in anoxic environments
Bacteria live in anoxic environments, create cables to shuttle electrons from anoxic to oxidation zone (allowing O2 to be reduced). Cables allow breathing of oxygen while living in anoxic conditions
