Mitochondria

Question 1

What is one key property of internal mitochondrial membrane?

Answer 1

NOT PERMEABLE TO H+

Question 2

What is mitochondrial import and why is this needed?

Answer 2

THE MAJORITY OF GENES ARE IN THE CELL NUCLEI AND THUS PROTEINS WILL BE TRANSPORTED AND IMPORTED INTO THE MITOCHONDRIA

Only 2% of genes remain in the mitochondria, the rest have migrated to the nucleus

Reduced mutation, repair mechanism → safer to keep the genes in the cell nucleus

Question 3

True or False, Mitochondria contains ribosomes

Answer 3

True, in the matrix

Question 4

What is the origin of mitochondria during sperm transfer?

Answer 4

mitochondries paternels sont dégradés suite à la
fécondation

transmission only maternelle

Question 5

What is the impact of transmission maternelle?

Answer 5

Although the mother might have a few deffective (mutated) mitochondria but -> no real damage

Just by chance, the egg produced could contain a large number of defective mitochondria -> child can have mild or severe disease or not at all

Question 6

Where does the krebs cycle happen in the mitoch and what is another name for this?

Answer 6

dans la matrice
Acétyl-CoA cycle

Question 7

What is the product of Krebs cycle? Why is this important?

Answer 7

NADH et la Succinate: donneurs d’électrons

Creates a gradient of H+ proton gradient → strong electro-chemical potential:

This potential energy is used to turn ATP Synthase → Generate ATP from ADP and Phosphate

Question 8

TRUE or FALSE, ATP synthase can only synthasise ATP

Answer 8

FALSE, it can also Hydrolyze ATP

Question 9

What is Cardiolipine?

Answer 9

phospholipide specifique des membranes des bactéries et de mitochondrie

essentiel pour la chaîne respiratoire et pour l’imperméabilité aux H+

Question 10

What do we mean by, mitochodria are motile?

Answer 10

Les mitochondries sont dynamiques et
se fusionnent et se divisent based on environmental state

Question 11

What is Mfn?

Answer 11

Mitofusin
Important for Fusion of Mitochondria

Question 12

What is Drp 1?

Answer 12

dynamin-related protein 1
important for mitochondria fission

Question 13

At what stage do we find high concentrations of Drp1? What about low?

Answer 13

High -> during mitosis (to spread out mitochondria)
Low -> G1 and so, Drp 1 degraded via APC

Question 14

What would be the effect of blocking Drp1 activity?

Answer 14

Si on inhibe la fission (Drp1 inhibition), le cycle cellulaire s’arrête
en G2/M et ceci peut induire l’apoptose

Cytochrome C release -> Caspase9 Activation

Question 15

Which kind of mitochondria is more effective in ATP production? What metabolic state might you find wach?

Answer 15

Filaments:
Plus efficace à former
l’ATP -> important in famine

Graines:
Moins efficace à former
l’ATP -> important in obese people

Question 16

What do we mean by mitochondries sont important pour
la thermogenèse?

Answer 16

In extreme cold conditions -> activation of adipocyte brun

These types of mitochondria express UCP-1
UCP-1 is a potential pathway for H+ that leads to heat production

In addition, this leads to Drp1 activation -> more fission -> more graine mitochondria -> more heat