Biology question

[ana_mujahid]

sallam alekum/hello

The tubule cell contains a large number of mitochondria. they are needed for the cell to reansport glucose across the cell membrane into the blood. suggest a method that the cell uses to do this and explain you answer.


I think the answer is:

the process which the cell uses is diffusion, because once they diffuse the glucose molecules will diffuse from a region of high concentration to a region of low concentration.



is this right or wrong?

thanks need answers asap :)

[Unique Muslimah]

Wa Alaikum Salaam..
Is that the full question?

[Arsalan]

I just asked shiekh google about Differential diffusion, thats a more technical name for it.

http://faculty.southwest.tn.edu/jiwilliams/differential_diffusion.htm

This is what the sheikh said.

But the method transfer of the molecules depends also on the structure and layering of the membraine of the cell. Membraines may be less or more porous and so the type of diffusion depends on that.

I aint studied biology for over 10 years, thats all i remember...

[Mace]

Ana, if it's not too late (you said you need the answer ASAP), I think you're on the wrong track here.

[ana_mujahid]

Ana, if it's not too late (you said you need the answer ASAP), I think you're on the wrong track here.

no its not to late still got a few days, but i wana move on with my revision

[ana_mujahid]

I just asked shiekh google about Differential diffusion, thats a more technical name for it.

http://faculty.southwest.tn.edu/jiwilliams/differential_diffusion.htm

This is what the sheikh said.

But the method transfer of the molecules depends also on the structure and layering of the membraine of the cell. Membraines may be less or more porous and so the type of diffusion depends on that.

I aint studied biology for over 10 years, thats all i remember...

thankss :)

[Unique Muslimah]

Just out of curiosity,at what level are you studying bio?

[ana_mujahid]

Just out of curiosity,at what level are you studying bio?

Higher, final school year and i got a brain crash im forgetting everything :S :rubeyes::torture:

[Unique Muslimah]

Higher, final school year and i got a brain crash im forgetting everything :S :rubeyes::torture:

Oh right,so that's GCSEs.I dont think you learn about facilitated,differentiated diffusion up until AS/A levels.

[Mace]

no its not to late still got a few days, but i wana move on with my revision

Ok, here's what I think. The wording of the question is odd to me. But in any case, I assume the question is referring to the proximal tubules in the kidney.

One of the functions of these cells is to reabsorb glucose from the filtrate back into the bloodstream.

The reason diffusion (even facilitated) alone is not the answer is because under normal conditions these cells absorb 100% of the glucose out the filtrate (urine). So if you think about it, the glucose is going from an area of lower concentration in the filtrate to higher concentration within the cell.

There are really three mechanisms going on in these cells that are related to glucose re-absorption and the high concentration of mitochondria referenced in the question. (These cells have one surface facing the filtrate. This surface is called the apical membrane or lumenal surface. The other side, facing the blood supply, is the basolateral membrane.)

1.) You have an Na+ pump moving Na+ out of the cell across the basolateral membrane. This movement is powered by ATP and is necessary for #2 below to work. Because this is powered by ATP, you have a high concentration of mitochondria in these cells.

2.) Process #1 causes a low concentration of Na+ in the cell. This helps drive a type of secondary active transport across the apical membrane (lumenal surface). The way this works is that you have a higher concentration of Na+ outside the cell (lumen in this case), which will drive movement of Na+ inside the cell. And so you have particular proteins that bind to Na+ and glucose outside the cell and transport both to the inside. This is an active transport because glucose is being moved from low concentration to a higher concentration inside the cell. What's driving and powering this transport is the movement of Na+ from a higher concentration a lower one ("downhill" across the gradient).

3.) Glucose is then moved "downhill" across the basolateral membrane back toward the blood supply. This is diffusion from a higher concentration to a lower one, but it is facilitated by another class of transmembrane carrier. (in the case, specifically GLUT2). The reason a carrier is needed is because glucose cannot freely move across the membrane.

In summary in process #1 you have Na+ moving "uphill" against the gradient. In #2, you have Na+ moving "downhill" with the gradient. In #2 you also have glucose moving "uphill" and in #3 you have glucose moving "downhill" again.

If you'd like to read more here are some links:

A good description of this type of secondary active transport (across the apical membrane): http://highered.mcgraw-hill.com/sites/dl/free/0072437316/120068/bio04.swf

and here: http://www.lib.mcg.edu/edu/eshuphysio/program/section1/1ch2/s1ch2_36.htm

The overall process in the proximal tubule:

http://pcwww.liv.ac.uk/~petesmif/petesmif/why%20do%20we%20need%20kidneys/proximal%20tubule.htm (http://pcwww.liv.ac.uk/%7Epetesmif/petesmif/why%20do%20we%20need%20kidneys/proximal%20tubule.htm)

The sodium-glucose transport proteins on the lumenal side:

http://en.wikipedia.org/wiki/SGLT2

And the primary transport on the basolateral side (facilitated diffusion):

http://en.wikipedia.org/wiki/GLUT2


I hope this helps. Any questions?

[Unique Muslimah]

DUH its active transport.Cant beleive I didn't get that.
The mitochondrion are there for ATP and Energy,and of the 3 mechanisms,the only one that requires energy is Active transport:smack:

[ana_mujahid]

Oh right,so that's GCSEs.I dont think you learn about facilitated,differentiated diffusion up until AS/A levels.

IGCSE's more advanced than the normal GCSE's

Remember me in your duas please :(

[ana_mujahid]

Ok, here's what I think. The wording of the question is odd to me. But in any case, I assume the question is referring to the proximal tubules in the kidney.

One of the functions of these cells is to reabsorb glucose from the filtrate back into the bloodstream.

The reason diffusion (even facilitated) alone is not the answer is because under normal conditions these cells absorb 100% of the glucose out the filtrate (urine). So if you think about it, the glucose is going from an area of lower concentration in the filtrate to higher concentration within the cell.

There are really three mechanisms going on in these cells that are related to glucose re-absorption and the high concentration of mitochondria referenced in the question. (These cells have one surface facing the filtrate. This surface is called the apical membrane or lumenal surface. The other side, facing the blood supply, is the basolateral membrane.)

1.) You have an Na+ pump moving Na+ out of the cell across the basolateral membrane. This movement is powered by ATP and is necessary for #2 below to work. Because this is powered by ATP, you have a high concentration of mitochondria in these cells.

2.) Process #1 causes a low concentration of Na+ in the cell. This helps drive a type of secondary active transport across the apical membrane (lumenal surface). The way this works is that you have a higher concentration of Na+ outside the cell (lumen in this case), which will drive movement of Na+ inside the cell. And so you have particular proteins that bind to Na+ and glucose outside the cell and transport both to the inside. This is an active transport because glucose is being moved from low concentration to a higher concentration inside the cell. What's driving and powering this transport is the movement of Na+ from a higher concentration a lower one ("downhill" across the gradient).

3.) Glucose is then moved "downhill" across the basolateral membrane back toward the blood supply. This is diffusion from a higher concentration to a lower one, but it is facilitated by another class of transmembrane carrier. (in the case, specifically GLUT2). The reason a carrier is needed is because glucose cannot freely move across the membrane.

In summary in process #1 you have Na+ moving "uphill" against the gradient. In #2, you have Na+ moving "downhill" with the gradient. In #2 you also have glucose moving "uphill" and in #3 you have glucose moving "downhill" again.

If you'd like to read more here are some links:

A good description of this type of secondary active transport (across the apical membrane): http://highered.mcgraw-hill.com/sites/dl/free/0072437316/120068/bio04.swf

and here: http://www.lib.mcg.edu/edu/eshuphysio/program/section1/1ch2/s1ch2_36.htm

The overall process in the proximal tubule:

http://pcwww.liv.ac.uk/~petesmif/petesmif/why%20do%20we%20need%20kidneys/proximal%20tubule.htm (http://pcwww.liv.ac.uk/%7Epetesmif/petesmif/why%20do%20we%20need%20kidneys/proximal%20tubule.htm)

The sodium-glucose transport proteins on the lumenal side:

http://en.wikipedia.org/wiki/SGLT2

And the primary transport on the basolateral side (facilitated diffusion):

http://en.wikipedia.org/wiki/GLUT2


I hope this helps. Any questions?

wow thanks alot, u even gave me additional information inwhich i can gain extra marks with :up:

Overall the process is active transport because this requires energy which it take from the ATP.

i think i will learn most of the stuff u mensioned next year, i saved all the links u gave me and i will read them over my next break.
i read the second link and watch the clip because thats what im learning atm but not in such great detail.

Thanks again mace :up:

if u got any more science links as such email them to me, if u dnt mind :)

i better be off i need to get sleep cuz i gota wake up early tomorrow

good night, bye

[Unique Muslimah]

Trust me,all that stuff Mace posted,you don't even learn at AS level bio.

[Baybars]

Trust me,all that stuff Mace posted,you don't even learn at AS level bio.


Maybe they teach it at A-level in England; I'm not sure, but yeah, that all seams more like university level biology.

[ana_mujahid]

Trust me,all that stuff Mace posted,you don't even learn at AS level bio.

:rubeyes:

thats 2 years away, nor wonder why it sound confusing but interesting :)

i took the information i needed from it anyways :)
but no waste i can read the other information during my next half-term, after all i love biology:inlove:

[Mace]

after all i love biology:inlove:

Good!

Sorry if I overshot your course level a bit. When you get old like me all of school sort of gets mixed together. :)

The part I wrote is not as precise as the links I added, so if you are using this for reference later use the links, not my post. My post was an attempt to explain in my own words what is going on using such technical terms as "uphill" and "downhill." :)

[Unique Muslimah]

Good!

Sorry if I overshot your course level a bit. When you get old like me all of school sort of gets mixed together. :)

The part I wrote is not as precise as the links I added, so if you are using this for reference later use the links, not my post. My post was an attempt to explain in my own words what is going on using such technical terms as "uphill" and "downhill." :)

By uphill downhill,are u referring to going against concentration gradient etc?

[Mace]

By uphill downhill,are u referring to going against concentration gradient etc?

Exactly.

[Unique Muslimah]

Oh righty right.This is all good re-cap for me..:D
Bio's much better than Chem:(Take's a hell of alot longer to revise,but is so much more interesting.Who cares about instantaneous dipoles:rolleyes:

[ana_mujahid]

Oh righty right.This is all good re-cap for me..:D
Bio's much better than Chem:(Take's a hell of alot longer to revise,but is so much more interesting.Who cares about instantaneous dipoles:rolleyes:

u in a-lvls?

i also ned help in chem:o :p

[ana_mujahid]

http://www.bbc.co.uk/schools/gcsebitesize/teachers/biology/active_transport.shtml

[Arsalan]

Mace Explanation is advanced advanced A level standard ( like a A grade with an step level on the end) or first year Biology undergrad. highly Suitable depending on what level your aiming for . But you wont need to go into that much detail for A level, unless they syllabus has changed from when i studied Biology. "A" level

[ana_mujahid]

Mace Explanation is advanced advanced A level standard ( like a A grade with an step level on the end) or first year Biology undergrad. highly Suitable depending on what level your aiming for . But you wont need to go into that much detail for A level, unless they syllabus has changed from when i studied Biology. "A" level

atm im going my final year of IGCSE's, all my science teachers predict me A*'s, but u need to increase the time i revise because im forgetting stuff :S

[Arsalan]

atm im going my final year of IGCSE's, all my science teachers predict me A*'s, but u need to increase the time i revise because im forgetting stuff :S

Alhamdoulillah, so a BASIC reference to the basics of Mace' post using the language of Concentrnation gradient, and Active transport is more then enough. But not that much detail..

Make record cards ( small cards), with diagrams and bullet points on the main point of a key topic, it helped me when i used to study. You can then revise even when your frying your chips, or brushing your teeth ( if your low on time)

[ana_mujahid]

Alhamdoulillah, so a BASIC reference to the basics of Mace' post using the language of Concentrnation gradient, and Active transport is more then enough. But not that much detail..

Make record cards ( small cards), with diagrams and bullet points on the main point of a key topic, it helped me when i used to study. You can then revise even when your frying your chips, or brushing your teeth ( if your low on time)

i make revision notes :) tonnes of then though :(

thanks

[GAL-actic]

Oh righty right.This is all good re-cap for me..:D
Bio's much better than Chem:(Take's a hell of alot longer to revise,but is so much more interesting.Who cares about instantaneous dipoles:rolleyes:

lol I do...

[Unique Muslimah]

lol I do...

But Whyy?:rubeyes:

[GAL-actic]

But Whyy?:rubeyes:


It's interesting

[ana_mujahid]

bio and chem are both so cool :D

i love them both :inlove: :)

[ana_mujahid]

one of my friends at school said that the process of this is diffusion because its a tubule cell, i argued with him using the prove you guys posted.

what do u think?

[-Fady-]

all you gcseinibl level crap, here we just got school, and thats it! Alhamdulilah!

[ana_mujahid]

all you gcseinibl level crap, here we just got school, and thats it! Alhamdulilah!

school goes in lvls, and these levels are named

u cant expect a person in year one to learn the same topics as a person in year 11 :confused:

[Mace]

one of my friends at school said that the process of this is diffusion because its a tubule cell, i argued with him using the prove you guys posted.

what do u think?

Well in this case there are 3 processes going on. One is active (driven directly by ATP).

The second is a secondary active transport.

And the third is facilitated diffusion.

All 3 are part of the process of reclaiming glucose from the urine.

[ana_mujahid]

Well in this case there are 3 processes going on. One is active (driven directly by ATP).

The second is a secondary active transport.

And the third is facilitated diffusion.

All 3 are part of the process of reclaiming glucose from the urine.

oh, i dont think this is my level atm, maybe ill study this next year.

thanks anyway :up:

[-Fady-]

school goes in lvls, and these levels are named

u cant expect a person in year one to learn the same topics as a person in year 11 :confused:

yup 1-12!