Concept 9.2: Glycolysis harvests chemical energy by oxidizing glucose to pyruvate Flashcards
The word glycolysis means
“sugar splitting,”
Glucose, a six-carbon sugar, is split into
two three-carbon sugars
These smaller sugars are then oxidized and their remaining atoms rearranged to form
two molecules of pyruvate
glycolysis can be divided into two phases: the energy investment
phase and the energy payoff phase
During the energy investment phase, the cell actually spends
ATP.
this investment is repaid with interest during the energy payoff phase, when ATP is produced by substrate-level phosphorylation and is
reduced to NADH by electrons released from the oxidation of glucose.
The net energy yield from glycolysis, per glucose molecule, is
2 ATP plus 2 NADH
ATP is produced from a molecule of
glucose, our fuel
the first step called glycolysis and takes place outside the
mitochondria
to begin the process some energy
has to be invested
next the molecule is split in
half
now the molecule, NAD+ an electron carrier picks up electrons and a hydrogen atom from the carbon molecule becoming
NADH
the electron carriers play an important role by
transporting electrons to the mitochondria
in the final steps of glycolysis some
ATP is produced but not much
for every glucose molecule only two net ATPs are produced outside the
mitochondrion
