Cellular respiration is the process by which organisms break down glucose to produce energy in the form of ATP. It occurs in the mitochondria through four main stages: glycolysis, the Krebs cycle, the electron transport chain, and oxidative phosphorylation. There are two types of cellular respiration - aerobic respiration which requires oxygen and produces carbon dioxide and water, and anaerobic respiration which does not require oxygen and produces alcohol or lactic acid instead. Factors like the type of cell, oxygen levels, ATP levels, and carbon dioxide levels can affect the rate of cellular respiration.

3. This Photo by Unknown Author is licensed under CC BY-SA-NC

4. CELLULAR RESPIRATION
• Cellular respiration is the process
that occurs in the mitochondria of
all organisms.
• In this process, both plants and
animals break down simple sugars
into carbon dioxide and water and
release energy in the form of
adenosine triphosphate (ATP).
• C6H12O6+6O2
C6H12+6H2O+energy (ATP)

5. TYPES OF CELL RESPIRATION
Aerobic respiration
- Takes place in the presence
of oxygen.
- It occurs in the
mitochondria.
- The end products are
carbon dioxide and water.
Anaerobic respiration
- No oxygen.
- It occurs in the
cytoplasm.
- The end product is
alcohol.

6. STAGES OF CELLULAR RESPIRATION
1. GLYCOLYSIS
Glyco= glucose and Lysis= break down
- Glycolysis is the first stage of cellular respiration.
- It occurs in cytoplasm.
- Glucose (6C) is broken down into two molecules of 3-carbon
molecule pyruvate.
- ATP and NADH are produced as part of the process.

8. 2. OXYDATIVE
PHOSPHORYLATION
- Before the next stage can
begin, pyruvate is
transported inside the
mitochondria.
- The pyruvate releases one
molecule of CO2.
- It then combines with an
enzyme called Coenzyme A
to form the two-carbon
molecule acetyl coenzyme
A.

9. 3. KREB’S CYCLE / CITRIC ACID CYCLE
-It occurs in the matrix of the mitochondria.
-Cyclical series of oxidation reactions that give off
CO2.
-Turns twice per glucose molecule.
-Produces two ATP.

11. 4. ELECTRON
TRANSPORT CHAIN
- Occurs in the inner
membrane of the
mitochondria.
- Electrons are passed along
the chain, from one protein
to another.
- Electrons drop in energy as
they go down the chain and
until they end up with O2.
- 34 ATP are produced.
This Photo by Unknown Author is licensed under CC BY-SA

12. FEMENTATION
- Fermentation is the release of energy from glucose
with the absence of oxygen.
- 2 ATP is produced from glucose but not as efficiently
as with Aerobic respiration.
- There are two types of fermentation which are
alcoholic and lactic acid.

13. This Photo by Unknown Author is licensed under CC BY-SA
This Photo by Unknown Author is licensed under CC BY-SA-NC

14. FACTORS AFFECTING CELLULARRESPIRATION

15. 1. KIND OF CELL OR TISSUE
- Young and developing cells usually have higher
respiration rates.
- Developing and ripening of fruits and seeds.
- Older cells and structural cells and structural cells
respire at low rates.

16. 2. ATP
- Higher ATP reduces the rate of respiration.
- Usually occurs when other metabolic processes
slowed.

17. 3. OXYGEN
- Low oxygen can reduce Aerobic respiration and
increase Anaerobic respiration.

18. 4. CARBON DIOXIDE
- Higher CO2 level reduces the rate of respiration.

20. ACTIVITY!
1. What is cellular respiration?.
2. Briefly explain stages of cellular respiration.
3. Name the two types of cell respiration.
4. What three things needed for cellular respiration to
happen?.
5. Which part of the cell does glycolysis occur?.
6. Draw and label the mitochondrion.

21. REFERENCES
1. Gales, C. (2007) cellular respiration. Available from Slideshare.net at
https://www.slideshare.net/BiologyIB/cellular-respiration-powerpoint (accessed 14 February
2007)
2. Hugo, M.J. (2016) cellular respiration. Available from Slideshare.net at
https://www.slideshare.net/wuGenglin143/cellular-respiration-64528214 ( Accessed 30 July
2016)
3. Lehmkuhler, J. (2014) cellular respiration. Available from Slideshare.net at
https://www.slideshare.net/jlehmkuhler/cellular-respiration-notes-42616457 (Accessed 11
December 2014)
4. Magedy,B.( 2017) cellular respiration. Available from Slideshare.net at
https://www.slideshare.net/baselmagdy/9-cellular-respiration (Accessed 18 March 2017)
5. Rozeka01 2014, cellular respiration. Available from Slideshare.net at
https://www.slideshare.net/rozeka01/biology-unit-3-notes-cellular-respirat (Accessed 25
November 2014)
6. Yang, D. (2011) cellular respiration. Available at Slideshare.net at
https://www.slideshare.net/yang286/cellular-respiration-9394052 (Accessed 23
September 2011)