tca & Glycolytic Cycle

1. Welcome To Our Presentation
Presented By:
Saleha Akter
Roll: MUH1819012F
Aysha Sabrina
Roll: BKH1819044F
Md: Al-Amin
Roll: ASH1819040M
Tasniha Tabassum
Roll: BKH1819022F

2. Topic We Will Discuss
Mechanism of Carbohydrate
Breakdown via Glycolic and TCA
Cycle

3. Introduction
• Also known as Embden-Mayerhof-Parnas pathway or
EMP pathway
• It is a flexible or metabolic process .
• Main way to produce ATP in some tissues
• Glycolytic cycle occur in some micro organisms when
acetate is sole source of carbon
• This cycle is absent in higher organism
• Glycolysis is the central pathway used in the breakdown
of Glucose to extract energy
• It is essential for brain which is dependent in glucose for
energy

4. Glycolytic Cycle
• Glycolysis comes from
two Greek word
Glykoys= Sweet and
Lysis= breakdown
• Glycolysis is defined as
the sequence of
reactions converting
glucose to pyruvate or
lactate with the
production of ATP.

5. Glycolytic Cycle

6. Steps of Glycolytic cycle
• Sep-1: Phosphorylation
Glucose is phosphorylated by ATP .Glucose 6 phosphate is
more easily trapped in the cell compared to glucose
• Step-2: Phosphoglucose Isomerase
The structure of glucose-6-phosphate is rearranged to
Fructose-6-phosphate by glucose phosphate isomerase
• Step-3: Phospho Fructokinase
Fructose-6-phosphate is phosphoralyted to make Fructose-
1,6-biphosphate with magnesium co-fector

7. Continuous……
• Step-4: Aldolase
The aldolase splits Fructose 1,6 biphosphate into 2 sugars-
Dihydroxyacetone phosphate (DHAP) and Glyceraldehyde-3
phosphate(GAP) that are isomers with each others.
• Step-5: Triosephosphate Isomerase
The enzyme triosephosphste isomerase rapidly inter
converts the molecules of DHAP and GAP
• Step-6: Glyceraldehyde-3-
phosphateDehydrogenase
Glyceraldehyde-3-phosphate dehydrogenase converted
into 1,3 biphosphoglycerate.

8. Continuous…..
• Step-7:Phosphoglycerate Kinase
Phosphoglycerate kinase transfer a phosphte group from 1,3
biphosphoglycerate to ADP to form ATP and 3-phosphoglycerate
• Step-8: Phosphoglycerate Mutase
The phosphate group in 3-phosphoglycerate is moved to a new
loaction creating 2-phospate
• Step-9: Enolase
The enzyme enolase removes a molecule of water from 2-
phosphoglycerate to form phosphoenolpyruvic acid
• Step-10: Pyruvate Kinase
The enzyme pyruvate kinase transfer a phosphate group from
phophoenolpyruvate to ADP to form pyruvic acid and ATP .

9. Significance Of Glycolytic Cycle
• Glycolysis is the source of almost all energy
used by cells
• Pyruvate the end product of glycolysis provide
procure for the TCA cycle and for the synthesis
of other compound
• It is the key metabolic components of the
respiratory process in plants
• It is the only source of energy in erythrocytes
• Importance in skeletal muscle can survive
anoxic episode

10. Introduction
• Also known as Krebs cycle and Citric acid cycle
• TCA cycle is the central metabolic hub of the cell.
• It is the final common pathway for the oxidation of
fuel molecule such as amino acid ,fatty acid and
carbohydrates
• TCA cycle occur totally in mitochondria
• About 65-70% ATP synthesized
• Reduced co-enzyme are produced ATP

11. Tri-carboxylic Acid Cycle
• The Tri-carboxylic acid
(TCA Cycle) is a series of
enzyme catalyzed
chemical reactions that
form a key part of
Aerobic respiration in cell.
• It was discovered by Hans
Krebs in 1937 and he got
Nobel Prize 1953 for his
discovery of TCA cycle

12. TCA Cycle

13. Steps Of TCA Cycle
• Step-1: Formation of citrate
Acetyl Co join with oxaloacetate to form citrate.
• Step-2 & 3: Formation of Isocitrate
The citrate is then converted to Isocitrate
• Step-4 & 5: Formation of Alpha Keto-Glutarate
Isocitrate is than oxidated to alpha keto-glutarate which result in
the reduced of carbon dioxide. 1 NADH molecule is also form in
this step.

14. Continue……..
• Step-6: Conversion of alpha-keto-glutarate to succinyl co-A
Alpha-keto-glutarate is oxidised to form a 4 carbon molecule
which picks up co-enzyme A forming succinyl CoA. This
conversion is also formed NADH molecule
• Step -7: Formation of succinate
Succinyl CoA is converted to succinate (4 carbon molecule ) by
thiokinase and a molecule of FADH is produced
• Step-8: Formation of fumrate
Succinate is oxidized by succinate dehydrogenase to fumarate
and also a molecule of NADH-2 is produced

15. Continue…..
• Step-9:Formation of malate
The enzyme fumarase catalyses the conversion of fumarate to
Malate with the addition of H2O
• Step-10: Conversion of malate to oxaloacetate
Malate is then oxidized to Oxaloacetate by malate
dehydrogenase and also produced NADH

16. Significance of TCA Cycle
• Krebs cycle releases plenty of energy requires for various
metabolic activities of cell
• Provides the reducing power for the electron (hydrogen)
transport system ,produces pairs of hydrogen atoms which are
ultimately used to provide Energy to make ATP in oxidative
phosphorylation
• ATP Generation
• TCA cycle produce many important 4-C,5-C & 6-C organic acids
as the intermediates during the process
• It produces simple and harmless end products such as CO2 and
H2O
• Carbon skeleton are got which are used in process of growth
and for maintaining the cells
• Succinyl is used for synthesis of heme

17. TCA VS Glycolytic Cycle
Please Try To Make Some Difference
Between TCA Cycle & Glycolytic Cycle

18. Difference Between TCA Cycle &
Glycolytic Cycle
TCA Cycle Glycolytic Cycle
TCA cycle refers to series of chemical
reactions in which pyruvate is converted
to acetyl CoA
Glycolysis refers to the series of chemical
reaction in which a glucose molecule is
converted into 2 pyruvic acid molecules
A cyclic process A linear process
Only occurs in aerobic respiration Occurs in both aerobic and anaerobic
respiration
Connected with oxidative
phosphorylation
Not connected with oxidative
phosphorylation
Carbon dioxide is released Carbon dioxide is not released
Produces six NADH molecules and two
FADH2 molecules
Produces two pyruvate molecules ,two
ATP molecules ,two NADH molecules

19. References
• www.microbiologyinfo.com
• www.scienceabc.com
• www.biotech4you.com
• www.biolibretexist.com
• www.teachmephysiology.com
• www.wikipedia.com