1. Introduction & Biomedical importance

2. Importance Glucose is the most important-CHO.
Glucose is the major fuel to mammalian tissues and to the fetus.
Glucose is converted to other CHO e.g. glycogen for storage, ribose in Nucleic acid (DNA, ATP, NAD), Galactose in Lactose of milk, and in combination with proteins to form glycoprotein in cell members.
Diseases associated with carbohydrates include diabetes mellitus, galactosemia, glycogen storage diseases and Lactose intolerance.

3. Glycolysis
Glucose is metabolized to pyruvate in all mammalian cytosolic part of the cell.
Glycolysis can proceed aerobically anaerobically to give ATP to skeletal muscle.
Conversely, heart muscle which is poorly adapted to hypoxic conditions, so under anaerobic it cause is ischemia.

4. Glycolysis cycle 1G molecule splits into 2x3C - pyruvates.
ATP used per 1G = -2 ATP
ATP produced 1G= +2 x 2 = +4ATP
NADH produced 1G= +2 x 3= +6 ATPs
Net ATPS= 8ATPs

6. Control of Glycolysis
By 3 irreversible reactions:
A) HK
B) PFK
C) PK

7. INHIBITORS OF GLYCOLYSIS
Iodoacitate.
Arsenate.
Flouride.

8. Oxidation of Pyruvate to Aetyl-coA
Pyruvate + NAD + CoA pyruvate Dehydrogenase.
Acetyl CoA + NADH + H + CO2
Acetyl CoA is point of entry into TCA cycle.
Pyruvate dehydrogenase is inhibited by its end product acetyl CoA.
1 NADH ETC ATP.
1 CO2 given off.

9. Anaerobic Glycolysis
Glycolysis can proceed in the absence of oxygen, and end in lactate not pyruvate. When oxygen becomes available lactae is converted back to pruvate and pyruvate to acetyl-coA.
In cancer cells, glycolysis proceeds much faster than TCA can utilize pyruvate. Pyruvate accumulation ending up in Lactate (anaerobic glycolysis). This acid environment which favors tumor growth.
The Liver, kidney and heart take up Lactate and oxidize it but under hypoxic conditions they produce it.

10. Cori Cycle

11. Glycolysis in Erythrocytes
Glycolysis in erythrocytes always terminate in Lactate because of lack of mitochondria.
Produces less ATP, but synthesises 2,3,Biphosphoglycerate which is essential for releasing oxygen to the tissues – i.e. decreases the affinity of hemoglobin to oxygen.
See next slide

13. Substrates for the TCA cycle is acetyl-coA sources which are:
Fatty acids
Amino acids
Glucose
They all give acetyl-coA.

14. TCA (Kreb’s) cycle TCA occur inside the mitochondrion.
Oxaloacetate is driving force of cycle.
2 CO2 molecules released from one -2C acetyl CoA.
1 ATPs x 2= 2 ATPs produced per 1G.
3 NADH x 2= 6 NADH x 3 = 18 ATPs - per 1G.
1 FADH x 2= 2 FADH x 2= 4 ATPs - per 1G.
G is completely oxidized.

18. 3 Inhibitors: Fluoroacetate. Arsenate.
Malonate (Competitive inhibition).