The mitochondria is the power house of the cell, there are a various of different reactions that occur in the mitochondria, in this powerpoint we will explain what is the mitochondria, and also its structure and function and that is has a DNA and makes some of its proteins for it self

1. MITOCHONDRIA
STRUCTURE AND FUNCTION

2. Mitochondria Overview

3. • Mitochondria are always referred to as the
powerhouse of the cell.
• Mitochondria has sausage-shaped kind of like
organelles.

4. Mitochondria Double-layered
membrane
1. Outer Membrane
Made of a phospholipid bilayer
The outer membrane is very permeable
Allows molecules to move in and out

5. • 2. Inner Membrane
Another phospholipid bilayer
Not very permeable
 has lots of protein transporters and they very
closely regulate what is going inside and
outside of the mitochondria

6. Intermembrane space
• Space that exists between outer and inner
membrane
• Highly concentrated with proton ions (H+)
i. Helpful in electron transport chain

7. Cristae
• Within the inner membrane, there’s a specific
type of invaginations
i. Continuation of the inner membrane but
invaginates into the center
• The purpose is to increase the surface area for
lots of specific types of reaction

8. MITOCHONDRIAL MATRIX
• There are different solutes in it
• There are two particular things in the matrix
1. Mitochondrial DNA
2. Ribosomes

9. Mitochondrial DNA
• This is maternal DNA (only inherited from
mother)
• Has genes to make particular RNA to make
proteins

10. RIBOSOMES
• We need ribosomes to be able to translate
that RNA and make proteins
• These are proteins the mitochondria can make
on their own to help with their function

11. Functions of Mitochondria
1. Outer and Inner Membrane

12. • Outer and inner membrane plays a important
role in protein transport.

13. Protein transport

14. • Mitochondria have DNA
• Mitochondrial DNA can make RNA, which can
help to make some proteins
• But it doesn’t make all the proteins that it
needs to be able to function ▪ So, we have to
take some proteins from the nucleus

15. • The nucleus will help us to make RNA
• RNA will then make proteins
• And these proteins have to get sent into the
mitochondria

16. • Nucleus DNA makes RNA → come out via
nuclear pore
• mRNA will then combine with ribosomes
• Ribosomes will then synthesize proteins
• These proteins are unfolded. They’re not in
active form

17. Translocase of the outer membrane
• Mitochondria has special transporters that are specialized
in moving these unfolded proteins that it needs to be able
to perform reactions inside of the mitochondria
• It needs to transport across
• These proteins will get chaperoned, and then they will
bind to the little receptor
• The transporter is called translocase of the outer
membrane (TOM)
• Once the unfolded protein binds to the receptor It will
open up TOM and move this unfolded protein into the
intermembrane space

18. Translocase of the inner membrane
(TIM)
• Little chaperone protein will bind to it and
bring it to the next receptor on the inner
membrane
• It stimulates the receptor
• It opens up the next channel translocase of
the inner membrane (TIM) and pushes the
unfolded protein into the mitochondrial
matrix

19. In the mitochondrial matrix
• These proteins may be needed to perform
specific things, Maybe it’s an enzyme that
plays a role in lots of metabolic reactions
• So, we have some specific types of proteases
or other enzymes that will work on these
proteins and properly fold him together and
activate.
• and make into a specific special enzyme

20. In short
• Mitochondrial DNA only makes 15% of the
protein that’s needed That means we need
lots of proteins from the nucleus to help us to
perform a lot of the functions
• Mitochondria accepts protein in unfolded
form, brings them, and activates them by
folding them properly and then uses those for
their metabolic reactions

21. Functions of Mitochondria
2. Miscellaneous transport

22. Miscellaneous transport

23. ● For metabolic reactions to occur, we have to
move things right across the actual mitochondrial
membrane in and out
1) Carbohydrates
● Glycolysis, or gluconeogenesis has to occur
inside the mitochondrial matrix
2) Fatty acids
● Because they play a role in beta-oxidation
3) Amino acids
● Because they play a role in the urea cycle

24. ELECTRON TRANSPORT CHAIN

26. • ETC is Very critical to the function of the mitochondria
• Mitochondria is often time called as powerhouse of the
cell o Produces ATP
• ATP is power energy
• Found primarily on the inner membrane. We don’t see this
involved in the outer membrane
• these protein molecules make up these different
complexes like complex I-IV and a very special molecule
called ATP synthase

27. • (1) Conversion of pyruvate to acetyl-CoA
• Pyruvate gets converted into acetyl-CoA
• (2) Krebs cycle
• Acetyl-CoA goes to Krebs cycle
• From the Krebs cycle that occurs in the
mitochondria We have high-energy electron
transporters called FADH2 and NADH They carry
lots of electrons
• They have hydrogen called hydride ion

28. (3) Electron transport chain –
Oxidative phosphorylation
• They take, and transport these electrons onto these
proteins
• They drop the electrons off in them, and then these
molecules pass these electrons down the chain from
areas of high energy to areas of low energy
• Each time that happens, it pumps all these protons
(H+) out into the intermembrane space Remember,
intermembrane space is very rich in H+ (protons)

29. • H+ moves down the ATP synthase powerfully It
creates energy that the protein can harvest
• Naturally, ADP is stuck to ATP synthase
• As the H+ runs down the gradient
• As the electrons are being passed down ▪ It
creates energies that fuse these to form ATP
• This process is called oxidative phosphorylation

30. Side effect
● A side effect is that All these electrons that are getting
passed along the membrane
● Sometimes, some of these electrons can combine with
O2 and other molecules and H2O2 (hydrogen peroxide)
Superoxide free radicals (e.g., O2-) are formed.
● So basically, they can increase the formation of
reactive oxygen species (ROS) , Which is that unfortunate
side reaction from the electron transport chain

31. REACTIONS THAT OCCUR IN THE
MITOCHONDRIAL MATRIX

33. ● There are lots of metabolic reactions that can
occur in the mitochondria
• Especially, inner and outer membrane,
mitochondrial matrix, and cytoplasm

34. (1) Conversion of pyruvate into acetyl-CoA
● Once the glucose gets into the cell, it will
eventually get converted into pyruvate via
glycolysis
● Pyruvate will be into the mitochondrial
matrix, It undergoes a conversion into acetyl-
CoA

35. (2) Krebs cycle
● Acetyl-CoA will go into the cycle called the Krebs cycle
● Coming off of the Krebs cycle is high energy molecules
that carry electrons NADH and FADH2
● These go to electron transport chains, where they pass
off those electrons Pump H+ into the intermembrane
space
They help to generate ATP via oxidative phosphorylation

36. (3) 𝒃𝒆𝒕𝒂−𝒃𝒆𝒕𝒂−𝒐𝒙𝒊𝒅𝒂𝒕𝒊𝒐𝒏
● fatty acids A long chain, sometimes it can be 16
carbons long
• We can bring these into the mitochondrial matrix
across the membrane
• They can go through a series of metabolic
reactions where they get broken down into
acetyl-CoA to make energy
• This step is called 𝜷- oxidation

37. (4) Urea cycle
• Amino acids can be brought into the mitochondria as well
• Eventually, they can get metabolized and give way to products in
the Krebs cycle ,When it does that, it can give off ammonia
• Ammonia is really toxic
• Ammonia will go through a series of reactions called the urea
cycle
• It liberates urea which is less toxic in comparison to ammonia, and
it’s easier to be excreted
• The urea cycle occurs specifically in the mitochondrion and a little
bit in the cytoplasm

38. • (5) Gluconeogenesis
• We can take amino acids or odd-chain fatty acids,
and we can convert them into a specific substrate
• We can convert them back into pyruvate and
then back into glucose
• What is it called when we take molecules like
amino acid and odd chain fatty acids and make
glucose? Gluconeogenesis

39. • (6) From the Krebs cycle, we can take some of
these intermediates and make molecule
called heme
• Some of these molecules are synthesized in 2
places
• Mitochondrial matrix
• Cytoplasm

40. 7) Ketogenesis
• We can take acetyl-CoA, and we can shunt
them into making molecules called ketones
• Occurs in the mitochondrial matrix
• This process is called ketogenesis

41. APOPTOSIS

42. • Whenever there’s some process where a cell is infected or
is cancerous, or it needs to die o There are special
molecules present inside of mitochondrial matrix called
cytochrome C
• Normally, these molecules do not leak out
• So, there’s a protein called bcl2 that helps to prevent this
from occurring
• In apoptosis, we decrease the number of bcl2
• Now, we can’t control the cytochrome C molecules from
leaking out

43. • Cytochrome C molecules activate enzymes called
caspases
• Caspases are basically proteases
• They start ripping through a bunch of different
cells
• Damaging cell membranes, organelles
• And eventually cause the cell to undergo the
death process

44. Any questions