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Biology; Chemistry; Physics: Post your doubts here!

ashiqbal

ashiqbal

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Spidey21 said:
sorry to break it to you but maltose does not go through the visking tubing...BIG PARTICLES!! :D
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sorry to break it to you, but maltose does move through visking tube but form some reason, sucrose doesnt!

if you have read past papers, there have been experiments where saliva and starch are placed in a visking tube, and after some time, reducing sugar test is positive out of the tube proving "maltose can move through visking tube".

there have also been experiments where visking tube containing sucrose solution is suspended in water and water moves in the visking tube, making it larger or bigger., proving "sucrose cannot move through visking tube".

:cool: Totally Rocked!!:cool:
 
Spidey21

Spidey21

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ashiqbal said:
sorry to break it to you, but maltose does move through visking tube but form some reason, sucrose doesnt!
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sucrose does not travel cuz its a very big molecule compared to glucose and maltose does not cuz its a biggy as well..:D
 
asd

asd

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The guy above me (ashiqbal) is absolutely correct.
And don't follow those wiki/yahoo answers, they're not always correct.
see the girl's comment below that answer: I'm sorry, but there are a few corrections to the answer directly above mine..if this comes on time.

See, the salivary amylase is also called ptyalin. Starch is broken down to dextrin and maltose. (Maltose is not broken down in the mouth yet, as disaccharidases are mostly found on the membrane of the villi of the small intestine).

The rest is almost accurate, so there's no need for me to repeat.
 
ashiqbal

ashiqbal

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if you have read past papers, there have been experiments where saliva and starch are placed in a visking tube, and after some time, reducing sugar test is positive out of the tube proving "maltose can move through visking tube".

there have also been experiments where visking tube containing sucrose solution is suspended in water and water moves in the visking tube, making it larger or bigger., proving "sucrose cannot move through visking tube".

:cool: Totally Rocked!!:cool:
 
ashiqbal

ashiqbal

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asd said:
Don't run away, you gotta give me the water cooler!
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sorry no water cooler for you.:p though if u answer some more questions correctly (on 16th and 21st), you can get an A* in August. Sorry to keep you waiting!:D
 
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Spidey21

Spidey21

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ashiqbal said:
sorry no water cooler for you.:p though if u answer some more questions correctly (on 16th and 21st), you can get an A* in August. Sorry to keep you waiting!:D
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your not the one deciding Water coolers B)
and can you please let me know which year??
 
Spidey21

Spidey21

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ashiqbal said:
sorry no water cooler for you.:p though if u answer some more questions correctly (on 16th and 21st), you can get an A* in August. Sorry to keep you waiting!:D
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and please give me some reference info...thank you...:)
 
A

ayeshaK

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Vogue said:
wat R reducing sugars any way? nd plz name all of them.
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Reducing Sugars (Benedict's test). All monosaccharides and most disaccharides (except sucrose) will reduce copper (II) sulphate, producing a precipitate of copper (I) oxide on heating, so they are called reducing sugars. Benedict’s reagent is an aqueous solution of copper (II) sulphate, sodium carbonate and sodium citrate. To approximately 2 cm³ of test solution add an equal quantity of Benedict’s reagent. Shake, and heat for a few minutes at 95°C in a water bath. A precipitate indicates reducing sugar. The colour and density of the precipitate gives an indication of the amount of reducing sugar present, so this test is semi-quantitative. The original pale blue colour means no reducing sugar, a green precipitate means relatively little sugar; a brown or red precipitate means progressively more sugar is present.
Non-reducing Sugars (Benedict's test). Sucrose is called a non-reducing sugar because it does not reduce copper sulphate, so there is no direct test for sucrose. However, if it is first hydrolysed (broken down) to its constituent monosaccharides (glucose and fructose), it will then give a positive Benedict's test. So sucrose is the only sugar that will give a negative Benedict's test before hydrolysis and a positive test afterwards. First test a sample for reducing sugars, to see if there are any present bef7ore hydrolysis. Then, using a separate sample, boil the test solution with dilute hydrochloric acid for a few minutes to hydrolyse the glycosidic bond. Neutralise the solution by gently adding small amounts of solid sodium hydrogen carbonate until it stops fizzing, then test as before for reducing sugars.
 
ALI HUSSAIN

ALI HUSSAIN

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guys while making graph the dependent factor comes on y-axis nd independent on x-axis??m i rite??
cnfused:confused:
 
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