oxygen - need cardinal groups

Question 1

obligate aerobes

Answer 1

require O2 as a terminal electron acceptor for aerobic respiration

require oxygen to obtain energy from nutrients

Question 2

facultative anaerobes

Answer 2

prefer O2 as a terminal electron acceptor for aerobic respiration can undergo fermentation

uses oxygen when present, but can survive by using fermentation when oxygen is not available

Question 3

obligate anaerobes

Answer 3

O2 is toxic!!

use inorganic electron acceptors for anaerobic respiration

unable to use oxygen for energy producing processes, many are harmed by the presence of oxygen

Question 4

aerotolerant anaerobes

Answer 4

O2 is ignored

they use inorganic electron acceptors for anaerobic respiration

can tolerate oxygen but do not use it for growth

Question 5

microaerophiles

Answer 5

require O2 as a terminal electron acceptor for aerobic respiration but too much O2 is toxic

2-10% only!!!

require oxygen but can only grow in low concentration, lower than air concentrations

Question 6

Describe the difference between chemically defined and complex media.

Answer 6

In chemically defined media the exact chemical composition is known. In complex media contains extracts and digests of yeasts, meat, or plants. This makes it difficult to calculate elemental ratios.