Respiration is an intracellular oxidation process that breaks down organic substances to form simpler substances while releasing energy in the form of ATP and NADH. There are two types of respiration: aerobic and anaerobic. Aerobic respiration uses oxygen and fully oxidizes substrates to produce CO2 and H2O, while anaerobic respiration does not use oxygen and partially oxidizes substrates to produce products like ethyl alcohol and CO2. Glycolysis is the first step of aerobic respiration, which involves the breakdown of glucose into pyruvic acid through a series of enzyme-catalyzed reactions, producing 2 ATP, 2 NADH, and pyruvic acid as end products.

1. GLYCOLYSIS
T B GOWTHAM
22MIM21

2. RESPIRATION
• INTRACELLULAR OXIDATION PROCESS
• BREAKS ORGANIC SUBSTANCES
• FORMS SIMPLER SUBSTANCES
• RELEASE ENERGY (ATP,NADH)
• USES GLYCOSE AND OXYGEN AS RAW
MATERIALS

3. TYPES
• AEROBIC
• ANAEROBIC
AEROBIC ANAEROBIC
NEEDS MOLECULAR OXYGEN DOES’NT NEED MOLECULAR
OXYGEN
SUBSTRATE IS FULLY OXIDIZED SUBSTRATE IS PARTIALLY
OXIDIZED
END PRODUCT: CO2 & H2O END PRODUCT : ETHYL
ALCOHOL & CO2

4. AEROBIC RESPIRATION
AEROBIC RESPIRATION IS COMPLETED IN
• GLYCOLYSIS
• OXIDATIVE CARBOXYLATION
• KREB’S CYCLE
• ELECTRON TRANSPORT SYSTEM

5. GLYCOLYSIS
• IT IS A TYPE OF AEROBIC RESPIRATION
DEFINITION :
IT IS A SET OF REACTION WHICH INVOLVES
BREAKDOWN OF GLUCOSE(6C) INTO PYRUVIC ACID
(3C) BY USING ENZYMES AND RELEASE ENERGY
MOLECULE
C6H12O6 +2 ADP+ 2 NAD+ 2C3H4O3 +2 ATP+2 NADH

6. BY
• EMBDEN
• MEYERHOF
• PARNAS
IN
• YEAST

7. WHERE IT OCCURS?

9. ENZYMES INVOLVED
1. HEXOKINASE
2. PHOSPHOGLUCOSE ISOMERASE
3. PHOSPHOFRUCTO KINASE
4. ALDOLASE
5. TRIOSEPHOSPHATE ISOMERASE
6. GLYCERALDEHYDE 3 PHOSPHATE DEHYDROGENASE
7. PHOSPHOGLYCERATE KINASE
8. PHOSPHOGLYCERO MUTASE
9. ENOLASE
10. PYRUVATE KINASE

11. 1 Phosphorylation
A phosphate group from ATP is
added to glucose to form glucose6-
phosphate and ADP
HEXOKINASE

12. 2 Isomerization
The glucose-6-phosphate
undergoes isomerization to
fructose6-phosphate, which is a
ketose
Phosphoglucose isomerase

13. 3 Phosphorylation
The hydrolysis of another ATP provides
a second phosphate group, which
converts fructose-6-phosphate to
fructose-1,6-bisphosphate.
Phosphofructokinase

14. 4 Cleavage
Fructose-1,6-bisphosphate is split by
aldolase into two three-carbon
phosphate isomers: dihydroxyacetone
phosphate and glyceraldehyde-3-
phosphate.
Aldolase

15. 5 Isomerization
Dihydroxyacetone phosphate
undergoes isomerization to provide
a second molecule of
glyceraldehyde-3-phosphate.
Triose phosphate isomerase

16. 6 Oxidation and Phosphorylation
Glyceraldehyde-3-phosphate is oxidized to a carboxyl
group, while the coenzyme NAD+ is reduced to NADH
and H+. A phosphate group (Pi ) adds to new carboxyl
groups to form 1,3-bisphosphoglycerate.
Glyceraldehyde3-phosphate dehydrogenase

17. 7 Phosphate Transfer
A phosphate group from
1,3-bisphosphoglycerate is transferred
to ADP molecules , yielding high-
energy compound ATP.
Phosphoglycerate kinase

18. 8 Mutation
3-phosphoglycerate undergo
isomerization which moves the
phosphate group from carbon 3 to
carbon 2, yielding 2-phosphoglycerate.
Phosphoglycerate mutase

19. 9 Dehydration
Phosphoglycerate molecule undergoes
dehydration (loss of water) to produce
phosphoenolpyruvate, a high-energy
compound.
Enolase

20. 10 Phosphate Transfer
Phosphate groups from
phosphoenolpyruvate molecule is
transferred to ADP to form pyruvate and
ATP.
Pyruvate kinase

21. WHAT WE GET ?

22. END PRODUCTS
GRAND TOTAL
• 2 MOLECULES OF PYRUVIC ACID
• 2 NADH
• 4 ATP

23. NET GAIN
2 ATP + 2 NADH
6 ATP (2 NADH)+ 2 ATP = 8ATP

24. REFERENCE
• Reginald H. Garrett., Charles M. Grisham
(2017) BIOCHEMISTRY. University of Virginia,
611 – 633
• Geoffrey M. Cooper., Robert E. Hausman
(2007) THE CELL A MOLECULAR APPROACH.
Sinauer Associates,Inc. 84 - 86

25. THANK YOU