Skip to main content
25 votes
Accepted

Are cells guaranteed to get at least one mitochondrion when they divide?

Isn't there a possibility that cell division will result in a daughter cell with no mitochondria? Yes, there is always the possibility. However, there must be a strong negative selection pressure ...
S Pr's user avatar
  • 6,262
13 votes

Are cells guaranteed to get at least one mitochondrion when they divide?

In addition to S Pr's excellent example, I wanted to point out that some very recent research describes some special behavior in oocyte development specifically related to mitochondria selection. ...
Reginald Blue's user avatar
11 votes

Why is ATP synthase sometimes referred to as ATPase?

The way we were To understand why you may encounter ATP synthase referred to as ATPase, you need to be aware of the historical context ā€” the experimental work that preceded the knowledge of the ...
David's user avatar
  • 25.9k
11 votes

Are cells guaranteed to get at least one mitochondrion when they divide?

A typical animal cell has 1000-2000 mitochondria. From a statistical point of view, assuming a random distribution of the mitochondria and that the cell splits in half, the probability of having 0 ...
Underminer's user avatar
9 votes
Accepted

Can mitochondria be regenerated by the cell?

If we were to suppose, as in the question, that all the mitochondria in a cell 'died' ('were irreparably damaged' would be better, as they are not independently alive) without any other consequences ...
David's user avatar
  • 25.9k
9 votes

How many molecules NADH are produced in the Krebs Cycle?

This is slightly depending on which reaction you want to include into the cycle. I count four: One when Pyruvate is converted to Acetyl-CoA, one when Isocitrate is converted to α-...
Chris's user avatar
  • 51.7k
7 votes

Do mitochondria contain the genes to specify themselves?

The answer is a bit more complicated than that. Mitochondria contain their own genome called mitochondrial DNA (mtDNA), encoding 13 proteins that are part of respiratory complexes I, III, IV, and V, ...
MattDMo's user avatar
  • 15.3k
7 votes
Accepted

Why don't protons diffuse out of the mitochondria during chemiosmosis?

Diffusion, is by definition (Ficks Law) describing movement along or against some gradient (here its concentration) even if the mechanism of transport differ: active, passive, facilitated. The setup ...
SciEnt's user avatar
  • 407
7 votes
Accepted

Why do mitochondria have a phospholipid bilayer?

I think the question is based on a false premise: Poster: Now, mitochondria are said to have been archaea, right? Me: Wrong, Iā€™m afraid. The closest bacterial relation of mitochondria is ...
David's user avatar
  • 25.9k
7 votes
Accepted

How is a very small quantity of poison able to kill a large organism?

"Cyanide" doesn't refer to just one compound, but given the lethal dose you mention of "half a gram" you are probably referring to potassium cyanide, with a molecular weight of about 65g/mol, so 0.5 ...
Bryan Krause's user avatar
  • 45.9k
7 votes

How can the leakage of mitochondrial protons generate heat?

Uncoupling ATP synthesis from the ETC (electron transfer chain; this is where oxidation takes place) by thermogenin or any other method means that the energy used to generate or uphold the proton ...
Nicolai's user avatar
  • 4,391
7 votes

If there is such known "Mitochondrial Eve", does it means that all the mitochondrial dna in everyone's body is same?

The mitochondrial genome has a nonzero mutation rate, though estimates differ according to method. Estimates are approximately $10^{-8}$ per bp per year on average, and the mt genome is $\approx20,000$...
Maximilian Press's user avatar
7 votes
Accepted

What keeps mitochondria from multiplying out of control?

I'm guessing at the motivation for your question -- In the evolutionary history of eukaryotic cells, mitochondria were once free-living bacteria. What prevents them from acting as intracellular ...
acvill's user avatar
  • 8,296
6 votes
Accepted

Can mitochondria become cancerous?

Interesting question. As a prelude, I should probably mention that single celled organisms cannot get cancer as we understand and define it. Mitochondria are not, of course, single celled organisms, ...
De Novo's user avatar
  • 8,791
6 votes

If there is such known "Mitochondrial Eve", does it means that all the mitochondrial dna in everyone's body is same?

The M.DNA mutates about 1% in a million years, and because our Mt-Eve is 150,000 years old, our mitochondria are 0.15% different, or 99.85% the same globally, and 99.95% the same in Eurasia. The ...
bandybabboon's user avatar
  • 10.4k
6 votes
Accepted

How does mitochondrial uncoupling enhance performance in muscle cells?

Skeletal muscles have multiple systems that increase the rate of energy generation in response to faster energy consumption during excercise. System Rate Sustainability Phosphagen highest 10-15s ...
user7777777's user avatar
5 votes

Why is FAD, rather than NAD+, reduced in the succinate dehydrogenase reaction of the Tricarboxylic Acid Cycle?

There is a simple straightforward answer to this question, which I present here because the poster of the accepted answer seems unsure which of his three suggestions is correct, and therefore there is ...
David's user avatar
  • 25.9k
5 votes
Accepted

How many protons are pumped out per pair of electrons from NADH in oxidative phosphorylation?

It seems like the mistake is in complex III. Look at this image from here: It clearly shows the number of protons reduced in (and taken from) matrix and number of protons pumped into inter-membrane ...
another 'Homo sapien''s user avatar
5 votes
Accepted

Origin of the double membrane of mitochondria and chloroplasts

The answer lies in the protein composition of mitochondrial membranes, which undoubtedly prove that the outer membrane (OM) is of alphaproteobacterial origin, and the phagosomal membrane (if there was ...
István Zachar's user avatar
5 votes
Accepted

How did mitochondria make energy long ago?

You are asking a very interesting question. As you correctly mention, the substrates of mitochondrial metabolism (TCA or Krebs Cycle) are pyruvate and NADH, and, through oxidative reactions, ATP is ...
rlluc's user avatar
  • 134
5 votes

What will happen if mitochondria had a structure like lysosomes?

Mitochondria are double membraned organelles with an outer membrane which is a rod-like shape, and a convoluted inner membrane (Figure 1). Figure 1 On the other hand, a lysosome is a single-...
liliae's user avatar
  • 636
5 votes
Accepted

Protein-coding introns in mitochondrial genomes

Mitochondrial genomes differ greatly in size, coding potential and even whether they are circular or linear. Mammalian mitochondrial DNA is small (11ā€“28 kbp) and intronless. However the mitochondria ...
David's user avatar
  • 25.9k
5 votes
Accepted

Is Chemiosmosis a hypothesis or a theory?

Preamble Although there is a case for closing this question (it is two questions, the first of which is more linguistics, logic or philosophy of science, and the second well-covered in text books) I ...
David's user avatar
  • 25.9k
4 votes
Accepted

Electron Transport Chain in Mitochondria

The good ol'electron transport chain (ETC). Before beginning let us begin by looking at the structure of a mitochondrion and the purpose of the ETC. (source: tokresource.org) Take of note four things:...
M. Carter's user avatar
  • 205
4 votes

Does zygosity have meaning for mitochondrial variants?

You abosolutely can have mixed populations of mitochondria in a cell (it is in fact very common). Therefore when you sequence the mtDNA you will get a completely variable percentace of reads ...
Alex's user avatar
  • 41
4 votes

Does all cells in individual has same mitochondrial DNA?

In a homoplasmic individual, all mitochondria is the same. Therefor will be the same amongst cells and between siblings/mother. Unless some mutation occurs. A homoplastic individual either has all ...
pazchem's user avatar
  • 81
3 votes
Accepted

Can Oxaloacetate cross the outer mitochondrial membrane?

In general the outer mitochondrial membrane is thought to be basically permeable (through porins) to small molecules such as OAA. As is typical in biology, the situation may actually be more complex --...
Victor Chubukov's user avatar
3 votes

Is human mtDNA unique in its single origin?

You can trace back any piece of DNA (from any life form) to a single ancestor called LUCA (Last Universal Common Ancestor), so the short answer is 'yes'. But be careful in your interpretation. If you ...
Remi.b's user avatar
  • 68.1k

Only top scored, non community-wiki answers of a minimum length are eligible