Download Cellular respiration

Glycolysis and Respiration
A.
The Catabolism of Carbohydrates
1.
Glycolysis
 Partial oxidation of glucose to form pyruvic
acid.
 A small amount of ATP is made.
 Some NAD is reduced to form NADH.
 The major glycolytic pathway in cells is the
Embden-Meyerhoff-Parnas pathway
2.
Fermentation and Respiration: Two Possible
Fates of Pyruvic Acid
Examples of Fermentation: Lactic Acid Fermentation,
Ethanol Fermentation
2.
Fermentation & Respiration: Two Possible Fates for
Pyruvic Acid
Carbohydrate in Medium
Transport proteins in Cell Wall
or Plasma Membrane

Carbohydrate inside Cell
Various Enzymes

Glucose or other Glycolytic Intermediates
Glycolysis
Pyruvic Acid (Partially oxidized)

Two Possible Fates of Pyruvic Acid
Fermentation
Pyruvic acid is reduced to:
a reduced organic acid
(for example, lactic acid or
mixed acids)
or an alcohol
(for example, ethanol or
butanediol)
OR
Respiration
Pyruvic acid is oxidized
completely to CO2
Gases (CO2 or H2) may
be produced
Final electron acceptor is
the organic derivative
of pyruvic acid
Final electron acceptor is
an inorganic molecule,
almost always O2,
but some bacteria use
nitrate, sulfate, or sulfur
Oxygen is not required
Oxygen is usually required
No additional ATP are made
Additional ATP are made
3.
B.
Stages of Respiration
a.
Preliminary Reaction: Pyruvic Acid is
converted to Acetyl CoA and CO2
b.
The Citric Acid Cycle (Krebs Cycle):
The acetyl group is completely oxidized to
CO2, with the formation of NADH and
FADH
c.
The Respiratory Transport Chain:
The energy in NADH and FADH is
converted into ATP; NAD and FAD are
regenerated.
The Regulation of Glucose Metabolism
1.
Allosteric Regulation of Phosphofructokinase
2.
Glycogen Synthesis
3.
Fatty Acid Synthesis