The organelle in eukaryotes where the main stages of respiration occur.

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

I have searched the web and found that 10 protons are suppose to get pumped out during the electron cycle, but i'm a bit confused. I'm trying to count, for every complex(1/3/4), the number of protons ...
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17 views

Mitochodrial osmotic flux

If you incubate mitochondria in isosmotic solution of Tris/EGTA and KCH3COO solution with rotenone, no swelling occurs at first - i.e. no ions enter the matrix so water doesn't follow to compensate ...
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Heteroplasmy in different tissues

I have only started reading the substantial body of research on heteroplasmy. I was curious if anyone knew of attempts to measure the somatic cell mtDNA mutation rate, to see if it differed from the ...
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131 views

Are mitochondria alive? [duplicate]

I'm working on an assignment for my IB biology class and some assistance would be highly appreciated. I've read several articles and I still haven't quite gotten the answer I'm looking for. I have to ...
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15 views

Rates of evolution of mitochondrial genes

I am interested in knowing the rates of evolution of different mitochondrial genes (in base pairs per million years) across different taxa. Has there been any publications along these lines ?
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25 views

how to find full mitochondrial genome of plants in GenBank?

I am searching for full mitochondrial genome of a species of Malvaceae family. To be more specific, I need the genus Corchorus. ...
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1answer
58 views

Is studying complete mitochondrial genome need biological lab work?

The research complete mitochondrial genome study done on species: Juema pig Sus scrofa (Suina: Suidae) from southern Gansu red rainbowfish speckled dace, Rhinichthys osculus white char Salvelinus ...
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47 views

What tools can help me determine if a plant homologous protein interacts with an ncRNA in the same way?

First post here, so bare with me if I violate any etiquette or formatting rules. Let's say I've got a protein in humans. When it interacts with an ncRNA found in humans, it does something that I'm ...
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Are mitochondria dead?

In the video "What is Life? Is Death Real?", the subject of mitochondria is raised at 2:58. At 3:12, the narrator says "[mitochondria] are not alive any more: they are dead." What currents of thought ...
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70 views

Genetic Diversity in Mitochondria

As I was studying for my GRE exam, I was reading on Mitochondria. I then remembered that they undergo replication similar to bacteria. So I googled for info and found on Wikipedia that there is a " ...
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154 views

Are mitochondria transferable between cell types, individuals and species?

I'm curious about what happens when you insert organelles from a cell into another. In particular, mitochondria. Take two cells from your own body. Somehow extract a mitochondria from one cell and ...
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33 views

Is 100% accuracy in DNA sequencing possible?

I would like to obtain a complete genome of a canine (with mitochondrial DNA too) at 100% accuracy. Is it even possible with the current technology? The source I have is potential degraded, i.e. dried ...
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41 views

How are the physiological properties of mitochondria measured?

this is my first question on BiologySE. I am a Physics and Mathematics student currently doing a project on cell growth simulation. I am doing literature survey and I have a question about cellular ...
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1answer
59 views

Are there eukaryotes with fully working mitochondria but without mitochondrial genes?

Are there eukaryotic organisms with fully working mitochondria that do not have genes in the mitochondria? By fully working, I mean ones which can carry out oxidative phosphorylation, unlike reduced ...
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1answer
49 views

How does loss of the electrochemical gradient result in heat production?

As far as I understand, uncoupling of the flow of protons and ATP-synthase provides a bypass for protons between the outer and the inner membrane of mitochondria so that the protons don't have to go ...
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1answer
77 views

Why doesn't mitochondrial DNA accumulate damage over successive generations?

From what I recall, mitochondrial DNA is very susceptible to damage from oxidative stress because it is a site where free radicals are generated and their DNA isn't packed into chromatin like nucleic ...
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1answer
38 views

Forensic genetics- why is mtDNA comparison sometimes better than nDNA comparison?

Why is (in forensic genetics) in some cases more appropriate comparison of nuclear DNA but in some other cases comparison of mitochondrial DNA? Is it because geneticists are sometimes unable to find ...
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1answer
102 views

Why is oxaloacetate made in the mitochondria?

I'm looking at the gluconeogenic pathway: Pyruvate is shuttled into the mitochondria from the cytosol, converted to oxaloacetate by pyruvate carboxylase, converted to malate which is then shuttled ...
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650 views

Father with mutated mtDNA- why isn't his offspring at risk?

Mothers transmit their mitochondria (and therefore mtDNA) to their offspring and fathers don't. Lets assume that father had a mutation of the gene that encodes mtDNA, would then be his offspring at ...
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1answer
666 views

Mitochondria - are they really separate organisms that once merged into eukaryotic cells?

Theoretically, mitochondria are said to be a separate organism that is concerned with its own life and its own processes. In fact, it even duplicates individually. I know a similar question is here ...
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188 views

Do macrophages engulf mtDNA?

Let us assume that in a human body, a mitochondrial DNA is released to extracellular environment. We know that mtDNA inheritance is solely matrilineal. So the question is, If your mitochondrial DNA ...
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1answer
126 views

Why is brown fat brown?

I read in Tortora and Derrickson Anatomy and Physiology that : Another type, called brown adipose tissue obtains its darker color from a very rich blood supply , along with numerous pigmented ...
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Was the mitochondrion or chloroplast first?

I still don't know if the mitochondrion or chloroplast was first? I've looked for it on the internet and in various books but haven't found anything. Does anyone have the answer and a theory which ...
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1answer
267 views

Plastid and mitochondria

I am not biologist, so please bear with me for this basic question. Although I tried googling, I am confused. What is difference between plastid, chloroplast and mitochondria? Are there any plant ...
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1answer
2k views

Which of the cell types commonly found in mammals has the greatest number of mitochondria?

This is basically a fun question, inspired by this answer on scifi.se. So, which cell type will have the greatest number of mitochondria? Obviously, I am talking about wild type, healthy individuals ...
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784 views

The Origin of Mitochondria

For a long time I've just accepted, because it is just what everyone told me, that mitochondria became organelles in the cell when they were "engulfed" by another cell which acted like it's host. This ...
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128 views

How much DNA of mitochondrial origin is incorporated in main cell's DNA?

And especially three points : in which chromosomes is it located (especially for the human case) ? how do we know about it ? does the proportion and composition vary a lot from one eukaryot to ...
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72 views

Common Ancestry of ETCs and ATP Synthase complexes

Rickettsiales are widely regarded as the ancestor of eukaryotic mitochondria through endosymbiosis. Cyanobacteria are widely regarded as the ancestor of eukaryotic chloroplasts through endosymbiosis. ...
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Why is FADH2 made instead of NADH in one of the reaction of Krebs cycle?

FADH2 is made in conversion of Succinate to Fumarate. Why is this so ? Why not NADH ?
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2k views

Why in some cells is GTP made in citric acid cycle and in some ATP?

In many animals GTP is produced in citric acid cycle. While in plants,bacteria and some animals ATP is produced. Why is this so ? What is the advantage ?
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1answer
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Why do brain cells use shuttles that pass electrons from NADH to FAD?

Brain cells are cells require one of the highest amount of energy of any cell of body. So why do they use a shuttle which will transfer electrons from NADH produced in glycolysis to FAD(and there by ...
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1answer
967 views

Is there any advantage of having a mitochondria for aerobic respiration?

If we consider the pathway of breakdown of glucose which includes glycolysis, the citric acid cycle and the electron transport chain, all these processes takes place in some prokaryotes and ...
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1answer
137 views

Why is there sperm mitochondrial suicide?

The mitochondria in the sperm are digested upon entry into the egg, making mDNA inheritance exclusively female. What is the advantage of this? Wouldn't some male mDNA be beneficial because of the ...
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1answer
85 views

Do mitochondrial DNA have repair enzymes?

Mitochondria are considered endosymbionts originated from a prokaryote. So, do they have a DNA repair mechanism ?
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1answer
2k views

Why don't antibiotics affect mitochondria?

Given that mitochondria are evolutionarily closely related to bacteria, and antibiotics kill bacteria, why don't antibiotics also kill mitochondria?
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692 views

Mitochondrial DNA and recombination

Firstly I could do with a brief description of mitochondrial DNA. How does the structure of DNA in mitochondria compare to animal DNA (for the sake of simplicity let's say human - some animals might ...
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110 views

Cell Respiration and Oxidative Phosphorylation

Why and how does the proton travelling through the stalked particle in the inner mitochondrial membrane, cause a conformational change in the ATPase?
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1answer
387 views

What preceded ATP synthase?

ATP Synthase is ubiquitous throughout life on earth and so most probably evolved within the last universal common ancestor (LUCA) before that lineage diversified into the various kingdoms of life. ...
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1answer
53 views

PGC-1β Sod2 limiters/blockers

I'd like to block a percentage of PGC-1β or Sod2 expression. According to the following paper's figure beta-blockers inhibit some expression of PGC-1α. Are there any medicines/chemicals which safely ...
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1answer
49 views

mutant down but not out

I am interested in a gene which is null lethal but I need to temporary induce diminished capacity. If a cell is homozygous is it possible to induce heterozygous phenotypes or a partial knockout from ...
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1answer
3k views

Slow-oxidative fibres vs fast-glycotic fibres

Why do slow oxidative muscle fibres contain more mitochondria compared to fast-glycolytic muscle fibres?
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1k views

Does every mitochondrion in a cell contain the same DNA?

I know that mitochondria of eukaryotes have their own DNA, more similar to that of bacteria than to the rest of the cell's DNA. I also know that a cell can have plenty of mitochondria, and I ...
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1answer
688 views

Why aren't mitochondria and plastids considered symbiotes of eukaryotic cells?

Mitochondria and plastids have their own DNA, their own membranes, and their reproduction is not tied to the reproductive cycle of the host cell. However, they are considered to be organelles rather ...
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1answer
634 views

How fast does the rotor in ATP synthase spin?

I'm sure the exact frequency varies, but does anyone know roughly how many revolutions per minute / second the rotating center part makes?
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1answer
109 views

Pancretic Acinar Cell - ATP, calcium concentration data

I need to find a decent source of data for concentration of ATP and calcium in the pancreatic acinar cell. So far all I can find is ATP or calcium 'levels' based on fluorescence , which are not ...
9
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1answer
470 views

How is the number of mitochondria in a cell regulated?

How does the cell regulate the number of mitochondria in a cell? What happens when there are too many or too few?
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1answer
344 views

What is the benefit for cells having the ATP production regulated in mitochondria compared to being from the nucleus?

Mitochondria have their own DNA and appear to be loosely connected to the nucleus and it role. Why are the functions of mitochondria not in the nucleus? Why doesn't the nucleus control the ...
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2answers
654 views

Do mitochondria simply automatically convert glucose to ATP?

I wonder whether there is any intelligent decision-making in mitochondria in the timing of their operation. Do they simply begin ATP production as soon as the correct reactants are present? Or, ...
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1answer
78 views

Substrates of cytochemical reactions in this immunostaining

Expression of extracellular protein Laminin 9 alpha-4 chain in human skeletal muscle. Indirect immunostaining with HRP immunostain marker. Ob.x40. I have unsuccessfully searched NCBI -database, JSTOR ...
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4answers
967 views

How many times did endosymbiosis occur?

According to the endosymbiont theory, mitochondria and chloroplasts originated as bacteria which were engulfed by larger cells. How many times is it estimated that this occurred in the past? Are there ...