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What else can I help you with?
Can grams iodine be used before primary stain?
Probably not. The CVI complex formed between the iodine and crystal violet will be trapped in the lipid layer and not the peptidoglycan layer, so you would probably end up over decolorizing. This would cause a lot of false gram negatives. Probably not. The CVI complex formed between the iodine and crystal violet will be trapped in the lipid layer and not the peptidoglycan layer, so you would probably end up over decolorizing. This would cause a lot of false gram negatives.
Why can starch molecules not pass through dialysis tubing?
Starch molecules are too large to pass through the pores of dialysis tubing. Dialysis tubing has small pores that restrict the passage of large molecules like starch while allowing smaller molecules like water and ions to pass through via diffusion.
How are starches broken down?
Starch is first digested into maltose in the mouth when the salivary enzyme (amylase) acts on it. Starch is not digested in the stomach. carbohydrases convert the remaining starch into glucose, the simplest form of sugar in the small intestine . Maltase also converts maltose to glucose in the small intestine.
Why is glucose allowed to pass through a semipermeable membrane and not starch?
Whether molecules are able to pass through the membrane depends on the size of the molecules. Smaller ones can, and larger ones cannot. Glucose can pass through a cell membrane because it is a monomer, which is a smaller molecule than the polymer molecules of starch.
What happens to any glucose that is not used in a plant?
Unused glucose in a plant is stored as starch in various plant parts, such as roots, stems, or leaves. This stored starch can later be converted back to glucose to provide energy for the plant's growth and development.
What substance is reqired to test for starch and what colour will it go?
Iodine is used to test for the presence of starch. In the presence of starch, iodine will turn from yellow-brown to a blue-black color.
What colour does bread go when you add iodine solution?
Bread turns blue-black when iodine solution is added due to the presence of starch. The iodine reacts with the starch molecules in the bread, forming a complex that gives this characteristic color change.
What is the color of potato cell if added with iodine solution?
iodine is an indicator for starch, potatoes are basically starch storage organs for potato plants. that's why they are good to eat, mmm starch!
What colour does idoine go if there is no starch present in a food?
If iodine is added to a food that does not contain starch, it will typically remain a brownish-yellow color. This is because iodine reacts with starch to produce a blue-black complex, but in the absence of starch, no such reaction occurs, and the iodine retains its original color.
How much iodine and starch do i have to us to test the vitamin c in citrus fruit?
To test for vitamin C in citrus fruit using iodine and starch solution, you will need a small amount of the juice from the citrus fruit (usually around 2-3 mL), along with a few drops of iodine solution and a pinch of starch powder. The iodine solution will turn blue-black in the presence of vitamin C due to the reduction of iodine to iodide.
Why is it that during titration of iodine or triiodine with thiosulphate the starch indicator should not be added until near the end point?
The Starch-Iodide complex is not very soluble in water, so the starch is added near the endpoint of an Iodine titration, when the Iodine concentration is low. This eliminates errors due to the fact that some Iodine may remain adsorbed on the complex and go undetected. so if you add the starch indicator only right near the end point when the solution is a light yellow colour the starch shouldn't complex and go lumpy.
What stain is used to show the presence of amyloplasts?
So I actually looked this up on this site this morning for my bio quiz and couldn't find the answer,.. well I've got it now so here you go,.. Iodine is used to take a look at the amyloplasts and Methylene blue is used to highlight the nuclei.
What would be the conclusion after testing a leaf for starch?
Starch is produced by leaves during Photosynthesis, therefore if the leaf has not been exposed to light then it will not contain starch, and so when tested the Iodine will stay Yellow/Brown. Consequently if the leaf has been left in the light Photosynthesis will have taken place and when tested the Iodine will go Blue/Black showing that Starch is present. Hope this helps :)
Why do you need freshly prepared starch solution for iodometric titration?
because,starch undergoes a photochemical reaction. So, with the passage of time it can under go to the photochemical reaction and starch wouldnot be starch but it might have changed in anyother product. so...we should use freshly prepared starch.
What colour does phenolphthalen go when an alkali is added?
Phenolphthalein turns pink/magenta in the presence of an alkali.
How can you test starch?
How to test for starch: 1. Add some starch powder to a test tube (or some ground up food that you want to test for starch) 2. Add cold water 3. Boil it to produce a clear solution 4. Once cool, add 3 or 4 drops of iodine solution 5. It'll go dark blue showing that starch is present
Is iodine molecule an organic molecule?
Iodine is not a compound. It is a pure element. As such it is not organic or inorganic. In general, organic compounds are molecules containing carbon, hydrogen and oxygen, though some contain sulphur, nitorgen etc.
