Fermentation Flashcards
Fermentation and anaerobic respiration enables
cells to produce ATP without the use of oxygen
most cellular respiration depends on
electronegative oxygen to pull electron down the transport chain
Without oxygen the electron Transport chain will
cease to operate
Anaerobic respiration uses
an electron transport chain with a final electron other than oxygen like a sulfate ion
glycolysis oxidizes
glucose to pyruvate without the involvement of O2 or an electron transport chain
NAD+ is the
oxidizing agent used in glycolysis
Glycolysis produces
2 ATP (net) by substrate-level phosphorylation whether O2 is present or not
Fermentation is an extension of glycolysis that oxidizes
NADH by transferring electrons to pyruvate or its derivatives
two types of common fermentation are
alcohol fermentation and lactic acid fermentation
In alcohol fermentation, pyruvate is converted to ethanol in two steps
- release CO2 from pyruvate
- produce NAD+ and ethanol
Alcohol fermentation by yeast is used
in brewing, winemaking and baking
Lactic acid fermentation, pyruvate is reduced directly by NADH to form
lactate and there is no release of CO2 in lactic acid fermentation
lactic acid fermentation by fungi and bacteria is used
to make cheese and yogurt
Skeletal muscle (red cells) oxidizes
glucose completely to CO2
White cells produces
lactate even under aerobic conditions
Fermentation, anaerobic, and aerobic respiration use
glycolysis to oxidize glucose and harvest the chemical energy of food. NAD+ is the oxidizing agent that accepts electrons during glycolysis
In fermentation, an organic molecule (pyruvate or acetaldehyde) acts as
a final electron receptor
In cellular respiration, electrons are transfered to
the electron transport chain
Fermentation produces 2 ATP by
substrate-level phosphorylation
Cellular respiration harvest up to 32 ATP by
oxidative phosphorylation
Obligate anaerobes carry out
fermentation or anaerobic respiration and can’t survive in the presence of CO2
Yeast and many bacteria are faculative anaerobes meaning that
they survive using either fermentation or cellular respiration
For facultative anaerobes, pyruvate is a
fork in the metabolic road leading to alternative catabolic routes
the mitochondria is not needed
for fermentation because it takes place in the cytosol
