anaerobic respiration and fermentation

obligate aerobes

use oxygen as final electron acceptor

obligate anaerobes

use co2, No2, so4 or fe as final electron acceptors, will die in presence of oxygen AKA anaerobic respiration

faculative anaerobes

tolerate oxygen or no oxygen environment

anoxic environment 

oxygen free

what can happen when NAD is limited

in glycolysis NAD→ NADH, but cells have limited supply, so step six will be blocked when none left, and glycolysis will end

if aerobic, ETC will oxidize NADH- NAD+

fermentation

cellular respiration pathway that transfers electrons from NADH to an organic acceptor molecule

less efficient at supplying energy, since it only produces ATP generates in glycolysis

Lactate fermentation

some single cells and animal muscles cells functions temporarily without oxygen

• lactate in muscle cells must be deoxidized to protect tissues

• oxygen is ultimately later needed to allow lactate to metabolize

• it is moved into blood and taken up by resting muscle cells to be converted into pyruvate or glycogenethano

ethanol fermentation

Yeast and bacteria are facultative anaerobes when no O2 available, they cover pyruvate into ethanol and CO2  , NADH passes hydrogen ions to acetaldehyde 

• alcohol