Lecture1 Flashcards
What did Rudolf Albert discover?
In 1856, describes ‘granules’
in muscles that later are found to be mitochondria
What did Richard Altmann discover?
In 1890, develops new staining procedures that allow him to describe ‘Bioblasts’, ‘elementary organisms’ that live inside cells
What did Carl Benda discover?
In 1898, uses crystal violet and
coins the term ‘mitochondria’
• ‘mitos’ - thread
• ‘chondros’ - granule
What did Leonor Michaelis discover?
In 1900, publishes a new
dye (Janus Green) that stains mitochondria
in living cells
What did George Palade and Fritiof
Sjöstrand discover?
In 1953, Electronmicroscopy
What did the Eletronmicroscopy by Palade and Fritiof bring?
brings the first
high-resolution images of
mitochondria
What is the length of MtDN
15kB, they isolated from mouse
liver reveals circular topology
When was the identification of mitochondrial
fibrils that are sensitive to
DNAse
in 1963
What is the name of the scientist that saw mitochondria for the first time?
Rudolf Albert von Kölliker
What kind of cells did Nass and Nass use for their electron microscopic images?
Chick embryo cells
How are respiratory deficient yeast cells called?
Petite mutants
In which year were mitochondrial ribosomes isolated from Neurospora crassa cells?
1967
What did Nass discover?
In 1963, was the first time that from mtDNA by Nass took image
What did Nass in 1963 saw?
He saw fibrils and then with Dnase it disapeard
Is mt always bean-shaped?
No, Mitochondria are not always bean shaped
How are Mitochondria
visualized?
by targeting a
fluorescent protein into
mitochondria
How Mitochondria are highly dynamic?
• Fusion and fission
events
• Transport along
cytoskeleton
What kind of experiments are paved the way to
understand the function of mitochondria?
Subcellular fractionation studies
What condition is crucial for the isolation of
intact mitochondria?
Isotonic conditions
How in 1948 did they found out that mitochondria are the site of respiration?
They put the mt in a hypotonic condition, then it swelling and water came inside of mt, and it Broken, non-functional mitochondria,, which leads to no respiration anymore (because the enzymes came out from mt)
Mitochondria, what Are they actually good for?
1) Energy production
2) Cell signaling
3) Ca2+ buffering
4) Apoptosis
5) Metabolism
Mitochondria, what Are they actually good for Metabolism?
- Amino acids
- Nucleotides
- Fe-S clusters
- Heme
- ß-oxidation
What is the power
plants of the cell?
Mitochondria,
Which part of Energy metabolism takes place in mt?
1) TCA cycle
2) Respiratory chain and oxidative phosphorylation
- > ATP
By which pathway Pyruvate produce?
Polysaccharides -> Monosaccharides (Glucose)
->Glycolysis ->Pyruvate
What is Glucose oxidation
yields?
2840 KJ/mol (almost 3000kj/mol) so not that much energy
How many Atp and NADH will produce per Glycolysis?
Glucose + 2 NAD+ + 2 ADP + 2 Pi—–> 2 Pyruvate + 2 NADH + 2 ATP + 2 H2O + 2
What you can say about 2 Atp producing per Glycolysis?
to hydrolysis Atp, we need 30KH/mol so lots of energy that produce in glycolysis left there in Glucose.
What is a pathway if we didn’t have a respiratory chain?
Pyruvate->1)Lactate(in muscle) NADH-> NAD+
2) in yeast Ethanol
NADH -> NAD+
How does Pyruvate enter mitochondria?
by Pyruvate carrier, transfer to matrix then pyruvate convert to Acetyl-CoA by PDH
Pyruvate dehydrogenase
By which Enzyme pyruvate convert to Acetyl-CoA?
PDH
Pyruvate dehydrogenase also producing NADH and co2
IS PDH a small complex? how many proteins does it consist of?
- A multienzyme complex
- One of the largest enzyme complexes known
- Consists of three different proteins (E1, E2 and E3)
What Coenzymes/Prosthetic groups does PDH have?
-Thiamine pyrophosphate (TPP) • Flavin adenine dinucleotide (FAD) • Coenzyme A (CoA) • Nicotinamide adenine dinucleotide (NAD) • Lipoate
What are the functions of E1, E2, and E3 of the PDH complex?
(1)E1 decarboxylates Pyruvate and
acetylates the lipoid group of E2
(2)E2 catalyses the transfer of acetyl to CoA
(3)E3 oxidises lipoamide moiety
In the picture descirbe
E2 is the green, E3 is the small red parts, E1 is the yellow surraonding one. we have also swinging arm
what other component can enter to pyruvate and acetyl-CoA conversation?
Fats->fatty acids and also Pro to -> a.a also a.a can enter to TCA directly
What are the names of the TCA cycle?
- Citric Acid Cycle (CAC)
* Krebs Cycle
By who is the TCA cycle discovered? when? and in what did the prize?
• Discovered by Hans Krebs in 1937
• Received the Nobel prize in physiology
and medicine in 1953
What is the pathway to entering pyruvate into the TCA cycle?
Pyruvate(that produced in the cytosol) enter then E1 decarboxylates pyruvate ant then pyruvate attach to the E1 enzyme and acetate transferred to the lipoid of E2 -> it transfers acetyl to coA-> what left is the enzyme with SH GP( then they reduced) and to keep continue the cycle the enzyme should oxidase again so E3 will transfer FAD to FADH
Which of the following statements are correct?
Select one or more:
a. The PDH is localized to the Intermembrane Space
b. TPP, FAD, CoenzymeA and iron-sulfur clusters are important prosthetic groups of the PDH
c. PDH is among the largest protein complexes known
d. ATP is generated by the PDH
e. The swinging arm of the E2 subunit facilitates substrate channeling
The correct answers are: PDH is among the largest protein complexes known, The swinging arm of the E2 subunit facilitates substrate channeling
A cell metabolizes glucose. What is the metabolite that is transported into mitochondria?
Pyruvate
What is the terminal electron acceptor of the respiratory chain in mt?
O2
