I Have A Few Qs About Mitochondria...

[Iam Joy]

Hi. I hope you can help me with this, because I'm not having much luck trying to find direct answers to these seemingly 'simple' questions...

 

1. How much energy do mitochondria emit/produce - let's say in a human; like if all the mitochondria were put in a bucket, how much energy would there be? Would it be enough to have any effect, such as being the equivalent of a small battery, or lighting a 60w light bulb, etc?

 

2. What kind of energy do mitochondria produce? All I ever read is that they produce 'energy', but it never says what kind of energy - I know this is a dumb question - but there are different types of energy aren't there? Is what they produce an actual type of electricity, or something else?

 

3. Why does mitochondria have its own DNA? What is the point of it carrying its own DNA?

 

4. Do all living cells in every living thing on Earth contain mitochondria? i.e. is mitochondria necessary in life for life to exist?

 

Thank you. I know some/all of my questions are dumb, but I'm just curious to know about things that interest me that I don't know about. :smile:

[blamski]

i can't answer all your questions, but there is strong evidence about why mitochnodria have DNA. Lyn Margulis' serial endosymbiosis theory tells us that mitochondria probably started out as free living proteobacteria. the genome of mitochondria are incredibly similar. in very simple terms, SET theory states that the cell as we now know it came about from symbiotic, and maybe even parasitic, relationships that went the extra mile and became fused together in the one organism.

 

not all living cells contain them, but the vast majority of eukaryotic cells do. the way the 'modern' call is set up its pretty much necessary, being as the mitochondria supply the cell's energy amongst other important tasks.

[maddog]

Hi. I hope you can help me with this, because I'm not having much luck trying to find direct answers to these seemingly 'simple' questions...

 

Thank you. I know some/all of my questions are dumb, but I'm just curious to know about things that interest me that I don't know about. :smile:

I think it's quite the opposite. I think your questions are all Very Good Questions! I am sorry, I may not be able effectively answer all of them. I will give my best attempt. :rolleyes:

 

1. How much energy do mitochondria emit/produce - let's say in a human; like if all the mitochondria were put in a bucket, how much energy would there be? Would it be enough to have any effect, such as being the equivalent of a small battery, or lighting a 60w light bulb, etc?

I do know there are about 100 trillion (10^12) cells in you body (I may be off by factor of 10 - too small). So to complete this calculation, you will need to find out how much ATP (question 2) is made per unit time, say 1 hour, and much energy one ATP molecule release during conversion. Multiplying those two together will give the total output of energy of mitochondria per hour. Multiplying that time the number of cells give you how much energy your body produces per hour. Be aware this number goes up and down depending on the activity. Muscles need a LOT of ATP to flex.

 

2. What kind of energy do mitochondria produce? All I ever read is that they produce 'energy', but it never says what kind of energy - I know this is a dumb question - but there are different types of energy aren't there? Is what they produce an actual type of electricity, or something else?

Yes, there are different sources of energy. Once converted to energy (expressed) it just becomes a unit of measure. In general there are two types of energy: Kinetic Energy and Potential Energy. You can see this in hold a ball a certain height above the ground followed by letting go of the ball. While holding the ball gravity exerts a force on the ball proportional to its mass. Once you let go the ball goes into free fall. This is an expression of its Kinetic Energy. For the mitochndria, how it produces energy is by creating a compound called ATP (Adenosine triphosphate) which when chemically converted to a different compound the energy released is used by the host cell.

 

3. Why does mitochondria have its own DNA? What is the point of it carrying its own DNA?

As blamsky was saying above. I heard this from a biology grad student when I was in college. It is thought a symbiotic relationship between most eukaryotic cells and mitochondria formed. Such a relationship benefits both sides. Another little know fact is that all progeny derive their source of mitochondria from the female sex in sexual type creatures (plants, animals, [fungi - I am not sure these are sexual in nature], ?). Makes sense since the male is only giving DNA in a vessel to deliver it (sperm).

 

4. Do all living cells in every living thing on Earth contain mitochondria? i.e. is mitochondria necessary in life for life to exist?

There are some types of bacteria that do not have mitochondria, nor do any viruses. I believe that type cellular create of the Kingdom Archea (bacteria like) also do not have mitochondria. They are thought to be the oldest type of lifeform.

 

maddog

Edited October 1, 2012 by maddog

[Moontanman]

Hi. I hope you can help me with this, because I'm not having much luck trying to find direct answers to these seemingly 'simple' questions...

 

1. How much energy do mitochondria emit/produce - let's say in a human; like if all the mitochondria were put in a bucket, how much energy would there be? Would it be enough to have any effect, such as being the equivalent of a small battery, or lighting a 60w light bulb, etc?

 

For a human at rest the energy output is someplace in the neighborhood of 100 watts, it can vary widely due to the exertion level of the individual.

 

2. What kind of energy do mitochondria produce? All I ever read is that they produce 'energy', but it never says what kind of energy - I know this is a dumb question - but there are different types of energy aren't there? Is what they produce an actual type of electricity, or something else?

 

Mitochondria produce chemical energy.

 

3. Why does mitochondria have its own DNA? What is the point of it carrying its own DNA?

 

Mitochondria are thought to be symbionts, chloroplasts in plants also contain their own DNA and are also thought to be symbionts, there are a couple other organelles that some think might also be symbionts.

 

http://en.wikipedia.org/wiki/Organelle

 

While most cell biologists consider the term organelle to be synonymous with "cell compartment", other cell biologists choose to limit the term organelle to include only those that are DNA-containing, having originated from formerly autonomous microscopic organisms acquired via endosymbiosis.[23][24][25]

Under this definition, there would only be two broad classes of organelles (i.e. those that contain their own DNA, and have originated from endosymbiotic bacteria):

mitochondria (in almost all eukaryotes)

plastids[26] (e.g. in plants, algae, and some protists).

Other organelles are also suggested to have endosymbiotic origins, but do not contain their own DNA (notably the flagellum - see evolution of flagella).

Under the more restricted definition of membrane-bound structures, some parts of the cell do not qualify as organelles. Nevertheless, the use of organelle to refer to non-membrane bound structures such as ribosomes is common.[27] This has led some texts to delineate between membrane-bound and non-membrane bound organelles.[28] These structures are large assemblies of macromolecules that carry out particular and specialized functions, but they lack membrane boundaries. Such cell structures include:

ribosome

cytoskeleton

flagellum

centriole and microtubule-organizing center (MTOC)

proteasome.

 

4. Do all living cells in every living thing on Earth contain mitochondria? i.e. is mitochondria necessary in life for life to exist?

 

Only eukaryotes, things like bacteria or archaea do not contain mitochondria.

 

From the above link

 

Eukaryotic organelles

Eukaryotic cells are structurally complex, and by definition are organized, in part, by interior compartments that are themselves enclosed by lipid membranes that resemble the outermost cell membrane. The larger organelles, such as the nucleus and vacuoles, are easily visible with the light microscope. They were among the first biological discoveries made after the invention of the microscope.

Not all eukaryotic cells have each of the organelles listed below. Exceptional organisms have cells which do not include some organelles that might otherwise be considered universal to eukaryotes (such as mitochondria).[29] There are also occasional exceptions to the number of membranes surrounding organelles, listed in the tables below (e.g., some that are listed as double-membrane are sometimes found with single or triple membranes). In addition, the number of individual organelles of each type found in a given cell varies depending upon the function of that cell.

 

Thank you. I know some/all of my questions are dumb, but I'm just curious to know about things that interest me that I don't know about. :smile:

 

I have heard it said the only dumb questions are the ones that do not get asked. If you want to know the answers to something do not feel hesitant to ask, no one here will think you dumb for asking.