Final Demonstration
Teaching
Maricel A. Marcelo, LPT, MAED
Instructor
Allan Jay C. Allauigan
Student Teacher
Put a lable on me!
Mechanics:
1.) Observe the diagram of the mitochondrion on the tarp.
2.) Identify and label the missing parts using the given pointers.
3.) Once finished, compare your answers with the correct labels provided
by the teacher.
Put a lable on me!
Answers:
1.
2.
3.
4.
5.
DNA
Ribosome
Inner membrane
Cristae
Outer membrane
Learning Objectives
At the end of the lesson, the stutent should be able to;
Recall the structure and function of mitochondria.
 Explain the process of cellular respiration and ATP production in the
mitochondrion.
 Demonstrate the correct labelling of mitochondrial structures using a
diagram or model.
 Recognize the significance of mitochondrial function in overall
cellular health.

The discovery of
mitochondria
The discovery of mitochondria began in the mid-1800s when scientists
observed granules in cells. By the late 19th century, researchers like Albert
von Kölliker and Richard Altmann identified these structures, with Carl
Benda later coining the term "mitochondria." Throughout the 20th century,
significant advancements were made in understanding mitochondrial functions,
including the identification of enzymes involved in cellular respiration and the
role of ATP.
The endosymbiotic theory was revived in the 1960s by Lynn Margulis, who
proposed that mitochondria originated from independently living bacteria that
were engulfed by another cell. This theory is now widely accepted and has
greatly influenced our understanding of cellular evolution.
What is Mitochondrion?
The mitochondrion, often referred to as the powerhouse of
the cell, plays a crucial role in energy production through
aerobic metabolism. It is a double-membraned organelle
found in most eukaryotic cells, responsible for generating
adenosine triphosphate (ATP), the energy currency of the
cell. Understanding its structure and function is essential for
biology students and professionals interested in cellular
metabolism.
Structure of Mitochondria
Outer Membrane: This is the outer layer that surrounds the
mitochondrion. It lets small molecules pass through but blocks large
proteins.
Intermembrane Space: The space between the outer and inner
membranes. It's important for making energy.
Inner Membrane: This membrane has many folds called cristae. These
folds increase the surface area for chemical reactions. It blocks most
molecules, keeping the inside environment just right for making energy.
Ribosome: Ribosomes are complex molecular machines found within all
living cells. They are responsible for synthesizing proteins by translating
messenger RNA (mRNA) into amino acid sequences. Ribosomes can be
found floating freely in the cytoplasm or attached to the endoplasmic
reticulum, forming rough ER.
DNA (Deoxyribonucleic Acid): DNA is the molecule that carries the
genetic instructions for the growth, development, functioning, and
reproduction of all known living organisms and many viruses. It consists of
two long strands forming a double helix, with each strand made up of
nucleotides that include a phosphate group, a sugar group, and a nitrogen
base.
Matrix: In biological contexts, the matrix refers to the extracellular matrix
(ECM), a network of proteins and other molecules outside the cells that
provide structural and biochemical support to surrounding cells. In a
broader sense, a matrix can also refer to an environment or medium in
which something develops or is contained.
Cristae: The folds of the inner membrane. They contain the proteins and
molecules needed to make energy.
Function of mitochondria
ATP Production: Mitochondria generate ATP (adenosine triphosphate)
through a process called oxidative phosphorylation. This involves the
electron transport chain and ATP synthase, which harness the energy from
electrons to produce ATP, the cell's main energy currency.
Cellular Respiration: Mitochondria are central to cellular respiration, a
series of metabolic processes that convert biochemical energy from nutrients
into ATP, while releasing waste products like carbon dioxide and water.
Calcium Storage: Mitochondria store and regulate calcium ions (Ca²⁺),
which are crucial for various cellular functions, including muscle
contraction, signal transduction, and cellular metabolism.
Apoptosis Regulation: Mitochondria play a significant role in
apoptosis, or programmed cell death. They release cytochrome c and
other factors that activate cell death pathways, helping to maintain
healthy cell turnover and tissue homeostasis.
Heat Production: In brown adipose tissue, mitochondria help generate
heat through a process called thermogenesis. This is particularly
important for maintaining body temperature in cold environments.
Metabolic Functions: Mitochondria are involved in various metabolic
pathways, including the citric acid cycle (Krebs cycle) and fatty acid
oxidation, which contribute to the overall energy metabolism of the
cell.
What would happen if there
were no mitochondria in a
cell?
Anaerobic Metabolism in the Mitochindrion
What is anaerobic metabolism?
Anaerobic Metabolism
Anaerobic metabolism is a type of energy production that occurs
without oxygen. It is used by cells when oxygen is scarce, such as
during intense exercise or in environments lacking oxygen. This
process happens in the cytoplasm and involves the breakdown of
glucose to produce energy in the form of ATP (adenosine
triphosphate).
Key processes of Anaerobic Metabolism
Glycolysis: This is the first step, common to both aerobic and
anaerobic metabolism. During glycolysis, one molecule of glucose (a
six-carbon sugar) is broken down into two molecules of pyruvate (a
three-carbon compound). This process produces a net gain of two
ATP molecules and two NADH molecules.
Fermentation: Since there's no oxygen to proceed to the Krebs cycle
and oxidative phosphorylation in the mitochondria, pyruvate
undergoes fermentation in the cytoplasm. There are two main types
of fermentation:
Lactic Acid Fermentation: In muscle cells and some bacteria,
pyruvate is converted into lactic acid. This process regenerates
NAD+, allowing glycolysis to continue. The buildup of lactic acid in
muscles can cause fatigue and soreness.
Glucose → 2 Lactic Acid + 2 ATP
Alcohol Fermentation: In yeast and some types of bacteria, pyruvate
is converted into ethanol and carbon dioxide. This process also
regenerates NAD+, allowing glycolysis to continue.
Glucose → 2 Ethanol + 2CO2 + 2 ATP
Why does anaerobic metabolism doesn’t
occur in mitochondria?
ATP production in Mitochondria
What is ATP?
ATP, or adenosine triphosphate, is the cellular “energy
currency,” and mitochondria are like the power plants that
generate it. The process of ATP production in
mitochondria is known as oxidative phosphorylation, and
it takes place primarily in the inner mitochondrial
membrane.
Key steps in ATP production
Glycolysis
- Glycolysis is the first step in the process of ATP (adenosine triphosphate)
production. It takes place in the cytoplasm of the cell and involves the
breakdown of glucose (a six-carbon sugar) into two molecules of pyruvate (a
three-carbon compound). This process results in the production of a small
amount of ATP and NADH (an electron carrier).
Pyruvate Oxidation
- Pyruvate oxidation is a key step in ATP production where
pyruvate, generated from glycolysis, is converted into acetyl-CoA in the
mitochondria. This process releases carbon dioxide and produces
NADH, which carries electrons to the electron transport chain for
further ATP generation.
Citric Acid Cycle
( Krebs Cycle )
- The citric acid cycle, also known
as the Krebs cycle, is a series of
chemical reactions in the
mitochondria where acetyl-CoA is
broken down. This process
generates NADH and FADH2,
which carry electrons to the electron
transport chain for ATP production,
and also produces a small amount of
ATP and releases carbon dioxide.
- The electron transport chain
(ETC) is a series of protein
complexes located in the inner
mitochondrial membrane. It transfers
electrons from NADH and FADH2
to oxygen, creating a flow of protons
across the membrane. This proton
gradient drives ATP synthase to
produce ATP, the cell's energy
currency.
- Chemiosmosis is the process by which
protons (H+) flow down their gradient
through ATP synthase, a protein in the
inner mitochondrial membrane. This flow
of protons drives ATP synthase to produce
ATP from ADP (adenosine diphosphate)
and inorganic phosphate, generating the
energy cells need.
Oxygen’s Role
-In ATP production, oxygen acts as
the final electron acceptor in the
electron transport chain. It combines
with electrons and protons to form
water, which allows the electron
transport chain to continue
functioning and ultimately drives the
production of ATP.
What is the significance of mitochondrial
biogenesis?
Mitochondrial Biogenesis
- Mitochondrial biogenesis refers to the process by which new
mitochondria are formed in the cell. Mitochondria are often referred to as
the "powerhouses" of the cell because they generate the energy needed for
various cellular functions. During mitochondrial biogenesis, existing
mitochondria grow, replicate their DNA, and divide to produce new
mitochondria. This process is essential for maintaining proper cellular
function, especially in response to increased energy demands or during
adaptation to environmental changes.
Mitochondrial Disfunction
Mitochondrial dysfunction occurs when mitochondria, the cell's energy
factories, do not work as they should. This can lead to a variety of health
issues because cells can't produce enough energy to function properly. Here
are some key points about mitochondrial dysfunction:
•
•
Causes: It can result from genetic mutations, environmental factors,
infections, or adverse effects of certain drugs.
Symptoms: Symptoms vary widely but can include muscle weakness,
fatigue, neurological problems, and organ dysfunction.
•
Affected Areas: It often affects high-energy-demand organs like the
brain, muscles, heart, and lungs.
•
Diagnosis: Diagnosing mitochondrial dysfunction can be complex and
may involve genetic testing, muscle biopsies, and other specialized tests.
•
Treatment: While there is no cure, treatments focus on managing
symptoms and may include dietary changes, supplements, and
medications to support mitochondrial function.
Role of Mitochondria in Apoptosis
Mitochondria play a pivotal role in apoptosis, which is a process of
programmed cell death essential for maintaining healthy tissues and
organs.
•
Release of Cytochrome c: When a cell receives signals to
undergo apoptosis, the mitochondria release cytochrome c into the
cytoplasm. This protein helps form the apoptosome, a complex
that activates caspases—enzymes that dismantle the cell.
•
Mitochondrial Outer Membrane Permeabilization (MOMP): This
process involves the formation of pores in the outer mitochondrial
membrane, allowing cytochrome c and other pro-apoptotic factors to
escape into the cytoplasm.
•
Regulation by Bcl-2 Family Proteins: Proteins from the Bcl-2 family
regulate mitochondrial membrane permeability. Pro-apoptotic members
(such as Bax and Bak) promote membrane permeabilization, while antiapoptotic members (such as Bcl-2 and Bcl-xL) inhibit it.
•
Apoptotic Signaling Pathways: Mitochondria are involved in intrinsic
apoptotic signaling pathways, which are triggered by internal stress
signals such as DNA damage, oxidative stress, or other cellular insults.
Mitochondrial Genetics
Mitochondrial genetics is the study of the genetic material found in
mitochondria, which are the energy-producing organelles within cells. Unlike
nuclear DNA, mitochondrial DNA (mtDNA) is inherited exclusively from
the mother.
•
Structure: Mitochondrial DNA is a circular molecule, distinct
from the linear DNA found in the cell nucleus. It contains 37
genes, which are essential for mitochondrial function.
•
Inheritance: mtDNA is passed down maternally, meaning it is inherited
from the mother. This non-Mendelian inheritance pattern allows
researchers to trace maternal lineage and study population genetics.
•
Mutations: Mutations in mtDNA can lead to various mitochondrial
diseases, which often affect high-energy-demand tissues like muscles
and the nervous system.
•
Role in Disease: Mitochondrial genetics plays a crucial role in
understanding and diagnosing mitochondrial disorders, which can result
from defects in mtDNA or nuclear genes that encode mitochondrial
components.
Mitochondrion Puzzle Challenge
Mechanics:
1.) Form a small group consisting of 4-5 member and recieve a set of
puzzle pieces.
2.) Work together to assemble the puzzle to reveal the labeled
mitochondrion diagram.
3.) You were only given 10 munites to assemble the puzzle.
4.) The first group to correctly complete the puzzle wins the challenge.
Quiz:
1. What is the primary function of the mitochondrion?
a) Protein synthesis b) Cellular respiration
c) Photosynthesis
d) Cell division
2. Which part of the mitochondrion is responsible for producing ATP?
a) Outer membrane
b) Inner membrane
c) Matrix
d) Cristae
3. Mitochondria are often referred to as:
a) The powerhouses of the cell b) The garbage collectors of the cell
c) The architects of the cell
d) The messengers of the cell
4. The inner membrane of the mitochondrion is folded into structures called:
a) Grana
b) Thylakoids
c) Cristae
d) Ribosomes
5. The space between the inner and outer membranes of the mitochondrion is
called:
a) Stroma
b) Cytosol
c) Intermembrane space
d) Matrix
6. Which process occurs in the matrix of the mitochondrion?
a) Glycolysis
b) Calvin Cycle
c) Citric Acid Cycle (Krebs Cycle) d) Electron transport chain
7. Mitochondria have their own:
a) Ribosomes b) DNA
c) RNA
d) All of the above
8. The endosymbiotic theory suggests that mitochondria originated from:
a) Bacteria
b) Viruses c) Fungi
d) Algae
9. Which of the following is NOT a function of the mitochondrion?
a) Detoxification of reactive oxygen species b) Apoptosis regulation
c) Energy production
d) Protein synthesis
10. The primary molecule produced by mitochondria that provides energy for
cellular activities is:
a) Glucose
b) ATP (Adenosine triphosphate)
c) DNA
d) Lipids
Assignment:
Do an advanced reading about the topic "Chloroplast and
Photosynthesis, and the Genetics Systems of Mitochondria and
Chloroplast".
"Fuel your ambitions with the power of your
inner mitochondria—tiny yet mighty, just like
your potential"