Glucose production

[ronthepon]

As part of a project, I wish to analyse the methods of glucose production. I intend to collect the conventional as well as conceptual methods of doing so.

 

I'm starting from the very beginning now. This thread will be my base for this endavour.

 

Now lets see... what all do I know about this?:lol:

 

Of course, glucose is the end product of photosynthesis. :jumpforjoy: Almost all plants produce glucose from sunlight, and they use carbon di oxide and water. This is the very beginning of the process.

 

Where do we get the glucose we package and sell? Hmmm... Wiki helps me here, we use the enzyme glucoamylase to hydrolyzse starch. Obviously, the conventional source of glucose is starch.

 

Where do we get our starch from? Well, I'd hasten a guess towards some cereal plant, but I'm not sure.

No, wait... it appears that corn is the raw material. [Link]

 

Fine, that's the prelims... Now the object is to find ways of producing glucose on a large scale. The intention is to find a source or mechanism from which we can get lots of glucose, fast and sustainably.

 

Won't you help me here? Any past knowledge, budding ideas or ...well... 'known connections' on the matter?

[Mercedes Benzene]

Well... in humans, glucose is produces mainly through the processing of glycogen. Our main source of glycogen comes from sources that are high in carbohydrates... although I don't think that glycogen itself IS a carbohydrate because it's a polysaccharide (you'll have to check to confirm this).

I believe that humans also produce glucose by liver synthesis of glycerine and some other non-carbohydrates.

The enzyme lactase produces glucose in small quantities as a result of the breakdown of lactose.

I'll do some reserach to see if bacteria may be used to produce glucose on a large scale. This seems unlikely since many bacteria USE glucose in their cellular processes, but we'll see....:lol:

[CerebralEcstasy]

Production of glucose syrup

 

This article talks about the enzymes required to produce glucose, and Canada Gazette this the strain of bacteria used to produce it.

 

2can Support Portal: Genomes - All Genomes

[ronthepon]

Interesting info, although the Canada Gazzete thing links to the newspaper:doh: You sure about it, CerebralEcstacy?

[CerebralEcstasy]

Interesting info, although the Canada Gazzete thing links to the newspaper:doh: You sure about it, CerebralEcstacy?

 

When I click that link this is what it goes to -

 

Provision currently exists in the Food and Drug Regulations for the use of the enzyme pullulanase from Bacillus acidopullulyticus NCIB 11647 in starch used in the production of dextrins, maltose, dextrose, glucose (glucose syrup), glucose solids (dried glucose syrup) or fructose syrups and solids, bread, flour, whole wheat flour and unstandardized baked goods at levels consistent with "Good Manufacturing Practice". A submission has been received for the use of pullulanase from a new source, a genetically engineered Bacillus licheniformis organism containing the pullulanase gene from Bacillus deramificans.

Extensive studies have determined the safety and efficacy of pullulanase from the new source. Therefore, the Food and Drug Regulations are amended to provide for the use of pullulanase from Bacillus licheniformis SE2-Pul-int211 (pUBCDEBRA11DNSI) at levels consistent with "Good Manufacturing Practice".

[ronthepon]

Funny... so it does...

[CraigD]

Given that photosynthesis is an efficient process that, with a little recycling, is in its simplest input/output form (2H, O, C, light)→(glucose), the ultimate large scale production method is to maximize its inputs. An obvious, if ambitious, way to do this is to bring the 3 elements, which are abundant in many small bodies in the solar system, as close to its main local light source as possible, and have some photosynthesizing stuff do its thing – in other words, a close-solar-orbiting, comet-eating green gloppy glucose factory in space. The ultimate end to such a business would be a total-solar-output-consuming Dyson sphere-like arrangement that would bind nearly all of the solar system’s carbon (the process’s limiting material, in solar space and the universe as a whole) into glucose – provided you’re ultimately willing to throw all the planets into its maw.

 

I may being thinking on too large a scale here :) And, whatever would you want with all that glucose? (about 2*10^27 kg, a bit more than 1 Jupiter)

[ronthepon]

But your lines of thinking happen to be my interests, CraigD, exactly.

 

If we can produce enormous amounts of glucose, well, we are using a rather ready-made process to store energy. We are actually producing usable fuel.

 

Currently, we can actually do that right here, on earth.

 

Now, lets see... how exactly does this light and carbon fixation work?

 

Step one: Light reactions of photosynthesis.

 

-Photolysis of water in photosystem II. Just how, exactly, I don't know for sure.

 

-Non cyclic Photophosphorylation, involving the formation of energy rich ATP.

 

-Cyclic photophosphorylation at times, when you're doing a bit of manipulations and... etc.

 

-Reduction of NADP to NADPH. Sorta involves the photolysis part, and... well...:) how exactly this happens I don't know.

 

Well... that's all I can think of, so we'll go to:

 

Step two: C3 cycle.

 

This is where I have even lesser knowledge. In general, I've known:

 

-Carboxylation of Ribulose Biphosphate with the assistance of rubisco. We'll not want photorespiration here, though.

This step forms Phospho-Glycerate.

 

-Reduction of 3phospho-glycerate... to form glyceraldehyde... which is eventually used to form glucose and all...

 

But how???

 

I really need some help.

[gribbon]

I can help with this one:

 

Photosynthesis has two main stages:

 

Photosynthetic electron transfer, also known as the "light reactions". Light energy becomes trapped in Chlorophyll molecules. This energy is used to make ATP and NADPH, and Oxygen is released.

 

Carbon fixation reactions, also known as the “dark reactions” or “the light independent reactions”. ATP and NADPH are used to convert CO2 into Carbohydrate.

 

The light reactions:

 

Energy from sunlight excites electrons of Cartenoid molecules, which pass their energy on to Chlorophyll molecules, which eventually passes the energy on to two central molecules of Chlorophyll. This energy then gets passed on to the photochemical reaction centre in the Thylakoid membrane system.

 

Here is the path of the electrons:

 

Firstly, they go through PSII, unhelpfully named so due to historical reasons. An enzyme that splits water is next to it, and as ach electron escapes from the chlorophyll to the photochemical reaction centre, another must take its place. The replacement electrons come from the split water, and when four have been split this way, hydrogen ions are formed, and a molecule of 02 is released. The Hydrogen ions leak out into the Thylakoid space, but we’ll come back to what they do later.

 

Meanwhile, the escaped electrons pass to the first protein in the sequence, plastoquinone, which then hands them on to the B6f complex, which pumps more hydrogen ions into the Thylakoid space. The accumulating ions store energy, and the electrochemical gradient is ever increasing. The ions move down the Thylakoid space, and then go through the enzyme ATP synthase, and as they do so, they drive phosphorylation in which ADP is converted to ATP.

 

Whilst all that is happening, the electrons, still waiting at the b6f complex, move on to the next protein, called plastocyanin, and then to PSI, here, they are given another boost of energy from another antennae complex, and so their level of energy is higher. They now have enough energy to pass to ferredoxin and latterly to NADP reducatase. This enzyme uses energy from the electron to convert NADP+ to NADPH.

 

Hydrogen ions pass out of the Stroma, and so increase the electrochemical gradient even more. Helping with the production of yet more ATP.

 

Overall, PSII produces ATP, and PSI produces NADPH and just over one molecule of ATP is produced for every molecule of NADPH. However, to get the correct quantity of ATP and NADP, the rest has to come from a process known as cyclic phosphorylation. (Note that all the steps from the splitting of water all the way up to converting the NADP+ is non-cyclic phosphorylation.)

 

Cyclic phosphorylation

 

Electrons can leave the chloroplast by another route. They are not used to make ATP, but instead they pass back to the b6f complex via ferredoxin and plastoquinone. They then go back to PSI, and in doing so, provide energy needed to pump hydrogen ions to the Thylakoid space.

 

That is all that is done during the daytime...

 

Then there are the dark reactions:

 

Try looking up the “Calvin Benson cycle” , but I’ll tell you what happens basically:

 

Ribulose Biphosphate has C02 added to it, turning it to a short-lived compound with six carbon atoms, which decays. The new molecules then enter the “Calvin Benson cycle”.

 

That’s as much as I know…you’ll have to look the rest up…

 

I hope that was helpful...;) :hyper:

[ronthepon]

You study bio, don't you, gribbon? Interesting, our knowledge in the matter seems to be very very close. The difference is that I've learnt the primary electron acceptor as pheophytin, and known the f6 complex as cytrochrome B6.

 

There's one difference though. ATP synthease? You mean the one with the F0 and F1 parts? You sure about that bit?

[gribbon]

You study bio, don't you, gribbon?

 

Not in school, but at home I read a bit about it...

 

The difference is that I've learnt the primary electron acceptor as pheophytin, and known the f6 complex as cytrochrome B6.

 

Pheophytin is a derivative of chlorophyll, which acts as the primary electron acceptor of Photosystem II, sometimes replacing Plastocyanin.

 

There's one difference though. ATP synthease? You mean the one with the F0 and F1 parts? You sure about that bit?

 

I'm not sure what you mean by "FO and F1 parts"...I didn't mention anything like that...ATP synthase is the enzyme which catalyses the adding or inorganic phosphate to ADP, turning it to ATP. :evil:

 

Oh well...

 

Maybe this will help you with understanding the fixation reactions (unfortunately, it seems to be written in french!) I've seen a few different versions of this, but this one seems to fit with my understanding best (they should have noted though that you need 3 molecules of CO2 to begin with, and it also produces 6 molecules of inorganic phosphate before it produces the amino acids, but it works overall):

 

[maikeru]

I'm not sure what you mean by "FO and F1 parts"...I didn't mention anything like that...ATP synthase is the enzyme which catalyses the adding or inorganic phosphate to ADP, turning it to ATP. :)

 

The "head" or "cap" of the ATP synthase enzyme is the F1 part, which changes conformation to clamp the inorganic phosphate to ADP (producing ATP), and FO is the base or stalk through which protons pass.

 

ATP synthase - Wikipedia, the free encyclopedia