Cellular respiration is the process by which cells generate energy (ATP) from food and oxygen. It occurs in the mitochondria of plant and animal cells through three main stages: glycolysis, the Krebs cycle, and the electron transport chain. Glycolysis breaks down glucose in the cytoplasm, the Krebs cycle further breaks down the products in the mitochondria, and the electron transport chain uses the Krebs cycle products to generate ATP through oxidative phosphorylation using oxygen as the final electron acceptor. Cellular respiration is essential for all living organisms to produce energy and is the opposite of photosynthesis.

1. CELLUAR RESPIRATION
(Process of synthesizing energy).

2. DESCRIPTION OF CELLULAR
RESPIRATION
The
process that synthesis energy (ATP) using
food and oxygen.
C H O + O → H O + ATP
6
12
6
2
2
(glucose)
Therefore
water and carbon dioxide is saved
as byproducts.
Cellular respiration is the opposite of
photosynthesis.

3. What type of cell undergoes cellular
respiration?
All
living organisms undergo cellular
respiration to produce energy.
Some organisms consume plants to obtain
food for cellular respiration e.g. herbivores.
Other organisms ingest other organisms e.g.
predators.

4. Cellular respiration in plant or animal
cells.
Cellular
respiration occur in the mitochondria
of plant and animal cells
Mitochondria is consist of two double unit
membrane (outer and inner) which is made
up of cristae.
Therefore it is found in the cytoplasm of
most cells.
The outer membrane is oval and the inner
membrane is folded.

5. Structure of mitochondria

6. Co- enzymes used during respiration
1. NAD+ → is a co – enzymes and
electron accepter. It accept 2
electrons and a hydrogen ion and form
NADH.
NADH can also give of electrons and
hydrogen ions to form NAD+ again.
2. FAD → is a co – enzyme and
electron accepter. It accept 2
electrons and 2 hydrogen ions to form
FADH .
2

7. Phases of cellular respiration
 Glycolysis
→ take place in cytoplasm and no
oxygen is needed for this stage(anaerobic).
Form glucose phosphate, a 6c compound.
 Kreb cycle/ citric acid cycle → takes place in the
mitochondrion and needs oxygen(aerobic). It
forms 2c compound (acetyl – group), acetyl
co – enzyme A (2c), citric acid (6c) and oxalic
acid.
 Hydrogen transfer system/ oxidative phosphorylation
→ takes place in the mitochondrial
membrane and need oxygen(aerobic). It uses
NAD+ to form NADH and ADP to form ATP.

8. Diagram of glycolysis

9. Diagram of kreb cycle/citric acid cycle

10. Diagram of hydrogen transfer system

11. LIST OF REFERENCES

Campbell, N.A., Reece, J.B., Urry, L.A.,
Cain, M.L., Wasserman, S.A., Minorsky, P.V.,
Jackson, R.B. 2010. Biology Eighth Edition.
Pearson International. 16:305-336.

Russell, P.J., Hertz, P.E., McMillan, B. 2012.
Biology: The dynamic Science. Brooks-Cole
Cengage Learning. 14: 286-302.