This document discusses carbohydrate metabolism, including glycolysis, gluconeogenesis, glycogenolysis, the pentose phosphate pathway, and blood sugar regulation. It explains that glycolysis breaks down glucose into pyruvate, producing a small amount of ATP. Gluconeogenesis converts non-carbohydrates into glucose when glycogen stores are depleted. The Cori cycle involves the liver converting lactate from muscles back into glucose. The TCA cycle further breaks down pyruvate from glycolysis to generate more ATP. Glycogenolysis breaks down glycogen into glucose as needed. The pentose phosphate pathway generates NADPH and pentoses from glucose-6-phosphate. Hormones like insulin regulate blood sugar levels.

1. GLYCOLYSIS AND
GLUCONEOGENESIS
CREATED BY: Dr. Pallavi
Pathania

2. Unit -III
• Composition and metabolism of carbohydrates
– Types, structure, compositions, and uses
• Monosaccharide
• Disaccharides
• Polysaccharides
• oligosaccharides
• Metabolism
• Pathways of glucose
• Glycolysis
• Glyconeogenesis : cori cycle, TCA cycle
• Glycogenolysis
• Pentose phosphate pathway
• Regulation of blood glucose level

4. • Carbohydrates are organic molecules.
• Carbohydrates are one of the main types of
nutrients. They are the most important source
of energy for your body. Your digestive system
changes carbohydrates into glucose (blood
sugar). Your body uses this sugar for energy
for your cells, tissues and organs.
• There are two types of carbohydrates:
– Simple
– Complex.

5. • Simple carbohydrates are smaller,
more easily processed molecules
known as mono- and disaccharides
since they contain either one sugar
molecule or two sugar molecules linked
together.
• Complex carbohydrates, are called
polysaccharides since they have more
than two sugar groups linked together.

9. STRUCTURES

10. • Carbohydrate function as bio fuel.
• Carbohydrate function as primary
source for energy.
• Carbohydrate function as storage of
food.
• Carbohydrate function as frame work
in body.
• Carbohydrate function as
anticoagulant.
• Carbohydrate function as hormone like
FSN,LH.(Glycoprotein)

11. METABOLISM
• The varieties of carbohydrates that are ingested are
converted in to mono saccharides with the help of
enzymes.
• These mono saccharides are absorbed in to the blood
stream in the small intestines.
• Where the carbohydrate metabolism begins.
• The sugar content in blood is controlled by three hormones.
• If the sugar content is high in blood , insulin is secreted by
pancreas which stimulates the glucose being transferred in to the
liver and muscular cells preferentially. In the liver the glucose gets
converted to glycogen. This is an anabolic process and is
called GLYCOGENESIS.
•

12. • The other two hormones are glucagon and epinephrine.
• These two help in stimulating the conversion of glycogen
to glucose when the sugar level in blood is low. This is a
catabolic process and is called GLYCOGENOLYSIS.
• The glucose entering in to the cell if needed to be
converted in to energy immediately a process called
GLYCOLYSIS takes place resulting in the formation of
pyruvic acid and adenosine triphosphate (ATP).
• The pyruvic acid if more ATP is needed gets converted
to acetyl CoA first and then to citric acid which will get
oxidized and gives ATP.

13. • When the energy is not required immediately the
pyruvic acid is converted back to glucose by a
process called GLUCONEOGENESIS.
This glucose in turn gets converted to glycogen and is
stored in the liver and muscle cells.
• This entire process is called the CARBOHYDRATE
METABOLISM.

14. 14
Pathways for Glucose

15. Catabolism

16. 16
Glucose
Glucose:
• Is the primary
energy source for
the brain, skeletal
muscle, and red
blood cells.
• Deficiency can
impair the brain and
nervous system.

17. Central Role of Glucose

19. Glycolysis
• Glycolysis is the breakdown of
glucose into pyruvic acid
• Does not require oxygen
• Occurs free in the cytoplasm
• Begins with D-glucose as the
substrate

20. Takes place in the Cytoplasm
Anaerobic (Doesn’t Use Oxygen)
Requires input of 2 ATP
Glucose split into two molecules of
Pyruvate or Pyruvic Acid
•Also produces 2 NADH and 4 ATP
•Pyruvate is oxidized to Acetyl CoA and CO2 is
removed

21. • Glycolysis involves the breakdown of
glucose molecules through a series of
reactions catalyzed by a set of enzymes.
.
• ROLE OF GLYCOLYSIS:- TO
PRODUCE ENERGY(BOTH
DIRECTLY & BY SUPPLYING)
SUBSTRATE FOR THE CITRIC
ACID & OXIDATIVE
PHOSPHORYLATION & TO
PRODUSE INTERMEDIATES FOR
BIOSYNTHETIC PATHWAYS.

23. The two parts of glycolysis:
glucose glucose 6-phosphate fructose 1,6-
diphosphate
Part one(enery invesment phase):
ATP ATP
Part two(energy generating phase):
fructose 1,6-
diphosphate
2 ATP 2 ATP2 NADH
2 pyruvic acid

24. Two phases of glycolysis

26. GLUCONEOGENESIS

27. 27
Gluconeogenesis: Glucose
Synthesis
Gluconeogenesis is:
• The synthesis of
glucose from
carbon atoms of
non carbohydrate
compounds.
• Required when
glycogen stores
are depleted.

30. CORI’S CYCLE

31. Cori Cycle
• When anaerobic conditions occur in active muscle,
glycolysis produces lactate.
• The lactate moves through the blood stream to the liver,
where it is oxidized back to pyruvate.
• Gluconeogenesis converts pyruvate to glucose, which is
carried back to the muscles.
• The Cori cycle is the flow of lactate and glucose between the
muscles and the liver.

32. Cori Cycle
• In the Cori cycle,
– Lactate from skeletal muscle is transferred to
the liver
– Converted to pyruvate then glucose
– This glucose can be returned to the muscle

34. TCA CYCLE

35. CITRIC ACID CYCLE

39. GLYCOGENOLYSIS
It is a breakdown of glycogen to release glucose

40. • Glycogenolysis occurs in 4
stages
– Phosphorylation
– Debraching
– Rearrangement
– Dephosphorylation

42. PENTOSE
PHOSPHATE
PATHWAY

44. BLOOD SUGAR
REGULATION

51. THANKS
THANKS