1.
Submitted to: Dr.Razia Noreen
Submitted by: BILAL IRSHAD
Subject title: Advance cell biology
Course code: BCH- 711
Topic: Why mitochondria
is called power house of cell?

2.
Mitochondria

3.
• Small, rod shaped organelles.
• Composed of a double membrane system.
• Outer membrane is smooth and encloses the
contents of mitochondria.
• Inner membrane is folded to form cristae.
• Inner cavity is filled with matrix which
contains many enzymes.
• Contain their own DNA which are
responsible for many enzymatic actions.

4.
Why Mitochondria is called Power
House of Cell?
• Involved in synthesize energy(ATP).
• ATP molecules provide energy for the
activities of living cells.
• So, mitochondria are often referred to
as the Powerhouses of the cell.

5.
Three main stages for production of
ATP:
Stage I: Glycolysis.
Stage 2: The Krebs Cycle.
Stage 3: Electron Transport Chain.

6.
Stage I: Glycolysis:
• The first stage Glycolysis takes place
outside the mitochondria in the
cytoplasm of the cell.
• The word glycolysis means
"splitting/lysis of sugar or glucose."
• The original glucose molecule has been
converted to two molecules of a
substance called pyruvic acid.

7.
Stage 2: The Krebs Cycle:
• Kreb cycle occurs in the matrix of the
mitochondrion.
• Energy-containing compounds from the citric acid
cycle is three NADH, one FADH2, and one ATP.
• Each acetyl CoA molecule joins a four-carbon
acceptor molecule. The reactions in the Krebs cycle
produce two more carbon dioxide molecules and
one ATP molecule per acetyl CoA molecule.
• At the end of the Krebs cycle, the four-carbon
acceptor molecule has been regenerated and the
cycle can continue.

8.
Stage 3: Electron Transport
Chain
The final stage occurs in the inner membranes
of mitochondria.
Components of ETC:
• FMN Flavoprotein.
• Fe.S Iron sulphur protein.
• Ubiquinone Q.
• Cytochrome (c,b,a,a3).

9.
Four Enzymes Complexes:
• Complex 1: NADH dehydrogenase: Complex I
receives electrons from NADH are simultaneously
transported from the mitochondrial matrix to the
intermembrane space.
• Complex 2: Succinate dehydrogenase: Complex II receives
electrons from FADH2. Electrons carried by ubiquinol are
sent to Complex III.
• Complex 3: Cytochrome bc1 complex: Four protons are
pumped into the intermembrane space.
• Complex 4: Cytochrome oxidase: The electrons pass from
Complex III. Cytochrome C carries the electrons to
Complex IV.

10.
ATP synthase:
• ATP Synthase is one of the most important
enzymes found in the mitochondria of cells.
• ATP synthase uses the energy from the flow of
H+ ions to convert ADP to ATP. This process
can generate up to 34 or 36 ATP molecules.

11.
Reference:
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4321783/
• https://www.expii.com/t/electron-transport-chain-
summary-diagrams-10139
• https://istudy.pk/electron-transport-chain/
• https://www.sciencelearn.org.nz/resources/1839-
mitochondria-cell-
powerhouses#:~:text=Mitochondria%20are%20tiny%20or
ganelles%20inside,the%20powerhouses%20of%20the%20
cell.
• https://bodell.mtchs.org/OnlineBio/BIOCD/text/chapter7/c
oncept7.5.html