Why cane can t be used to identify reducing sugars?

Because wheat seeds mainly contain starch, and starch is not a reducing sugar, so the identification of reducing sugar is generally the juice of apples, pears and other fruits that contain more reducing sugars and are lighter or nearly colorless.

Note that sucrose does not contain aldehyde groups (ketone groups) and therefore has no reducing properties, but the glucose and fructose produced by sucrose catalyzed hydrolysis are reducing sugars.

Fructose can produce a silver mirror reaction and a brick-red precipitate, while sucrose can't chemically prescribe that the one that can produce a silver mirror reaction and a brick-red precipitate is the reducing sugar, and it's as simple as that, not based on the hydrolyzed product, as you said.

No, sucrose doesn't get an aldehyde group.

Because direct hydrolysis of sucrose is not glucose, it is not a reducing sugar.

Identification of reducing sugars: The Filin reagent is composed of a solution of sodium hydroxide at a concentration of g mL and a solution of copper sulfate at a concentration of gram mL, which are mixed to produce a light blue Cu(OH)2 precipitate immediately.

Preparation of experimental materials: Plant tissues are commonly used experimental materials, but they must be selected. The ideal material for this experiment is biological tissues (or organs) with a high sugar content, and the color of the tissues is light, or nearly white, such as the fruit of apples and pears.

After experimental comparison, the obvious degree of color response was apple, pear, white cabbage leaf, and white radish.

Nature:

The sugar that can reduce Fehling reagent (Benedict reagent) or Torrance (reagent is called reducing sugar, and all monosaccharides (except dihydroxyacetone), regardless of aldose and ketose, are reducing sugars.

Most disaccharides are also reducing sugars, with the exception of sucrose. Filin reagent is a solution containing Cu2+ complex, which is reduced to obtain a brick-red Cu2O precipitate. When the Torrens reagent is reduced, it can produce elemental silver, which undergoes a "silver mirror reaction".

Sugars that contain reducing groups (such as free aldehyde groups or free ketone groups) in their molecular structure are called reducing sugars. Such as glucose. Fructose contains free ketone groups, so fructose is also a reducing sugar.

Reducing Sugar Identification:

Identification principle: There are many types of reducing sugars commonly found in biological tissues, including glucose, fructose, and maltose. They all contain reducing groups (free aldehyde groups or free ketone groups) within their molecules.

Filin reagent, Ban's reagent, silver ammonia solution, etc. can be used to test the presence or absence of reducing sugars in biological tissues.

1) Using Feilin reagent: Feilin reagent is prepared by sodium hydroxide solution with a mass concentration and copper sulfate solution with a mass concentration, and after the two are mixed, a light blue Cu(OH)2 precipitate is generated immediately. Cu(OH)2 and the added glucose are heated to produce a brick-red Cu2O precipitate, and the glucose itself is oxidized to gluconic acid.

The reaction formula is as follows:

ch2oh—(choh)4—cho＋2cu(oh)2→ch2oh—(choh)4—cooh＋cu2o↓＋2h2o

When reducing sugars are identified with Filin reagent, the color change process of the solution is: light blue, brown, brick red (precipitate).

2) Using Ban's reagent: Ban's reagent is prepared from liquid A (copper sulfate solution) and liquid B (sodium citrate and carbonic acid solution). Pour solution A into human solution B, stir while adding, and filter if there is precipitation.

The experimental principle is similar to that of Filin reagent, except that Ban's reagent can be used for a long time. The copper sulfate solution in Ban's reagent A and the anhydrous sodium sulfate and sodium citrate in B meet to produce soluble copper citrate that can slightly dissociate Cu2+.

3) Use silver ammonia solution: silver ammonia solution is a drop of dilute ammonia water in the agno3 solution of 2 until the initial precipitate is just dissolved, and the solution obtained at this time is the silver ammonia solution. The silver ammonia solution contains Ag(NH3) for 20H (silver diamine hydroxide), which is a weak oxidizing agent that can oxidize the aldehyde group to a carboxyl group, and Ag+ is reduced to metallic silver.

The silver produced by reduction adheres to the wall of the test tube, forming a silver mirror. It can be seen that the silver mirror reaction can also be used to identify soluble reducing sugars. The result of the identification was the appearance of a silver mirror.

Sucrose is the most widely distributed non-reducing disaccharide in nature. It is found in many plants and is most abundant in sugar cane and sweeteners, hence the name. Pure sucrose is a colorless crystal that is easily soluble in water and sweeter than glucose and maltose, but not if the sugar is sweet.

Sucrose is formed by the condensation of a glucose molecule and a fructose molecule and the loss of a water molecule. The fructose molecule belongs to non-reducing aldehydes, and the glucose molecule belongs to non-reducing ketones. Under the action of acid or sucrase, sucrose is hydrolyzed to produce equal amounts of glucose and fructose.

Therefore, its hydrolysate is reducible.

Many people believe that alternative sweeteners such as honey, brown sugar, or molasses are healthier than sucrose. However, this is not necessarily true. Sugar is a simple carbohydrate that your body uses for energy.

1.Boost energy.

Your body's main energy** is a simple sugar called "glucose", which comes from the breakdown of sugar. You'll often find liter sugars in fruits, dairy products, and cereals. But your body processes sucrose in the same way that it processes sugar in any other food.

It is broken down into two simple sugars at the same time – fructose and glucose. It can provide energy for the body, replenish muscle glycogen in time, and play a very obvious role in relieving muscle fatigue and restoring physical strength.

2.Moisturizing and dry.

Because from the perspective of traditional Chinese medicine food therapy, the white sucrose enters the lung meridian, for people with cough, phlegm, and asthma caused by lung dryness, proper consumption of sucrose has a good effect of moisturizing dryness, relieving cough and asthma.

3.Relieves abdominal pain.

For people with moderate and abdominal pain and bloating, eating sucrose appropriately has a good effect of relieving moderate and acute and relieving abdominal pain.

4.Control blood sugar levels.

When you consume more glucose than your body needs for energy, the excess glucose is stored in fat cells and the liver in the form of glycogen. This process helps your body's blood sugar levels return to normal.

This energy store is healthy as long as you don't eat more calories than you burn – like having a big gas tank in your car so you don't have to refuel as often. It allows your body to function without having to eat as often.

5.Boosts hormones.

Sucrose triggers the body's production of serotonin, a hormone that puts you in a good mood. A drop in serotonin levels in your body is the reason why you crave sugar, especially if you're tired or unhappy. When you eat sugary foods, you get a mood boost from serotonin.

The appearance of sucrose is dry and loose, white, shiny, and there should be no obvious black spots on the white paper, and the particles are divided into coarse, large, medium and fine grains, the particles are uniform, the grains are shining, and the contours are clear; The white sugar has fine grains, evenly covering the rotten celery, the color is white, and it is more soluble in water than white sugar, which is suitable for general drinks, snacks and other sugar foods; Red granulated sugar is crystalline or powdery, dry and loose, no agglomeration, no clumping, no impurities, its aqueous solution is clear, no precipitation, no suspended solids, Hongbi color has reddish-brown, green-brown, yellow-brown, red, golden, light yellow, jujube red and other historical groups; Rock sugar is uniformly white or yellow, translucent, with crystalline luster, and no obvious impurities.

Distinguish between glucose, fructose, sucrose, and starch.

The easiest way to distinguish glucose, fructose, sucrose, and starch is to talk about color in a whisper.

First of all, an appropriate amount of iodine solution is added to each of these four sugars, only the starch turns blue, and the other three sugars do not change color.

Then, in addition to starch, an appropriate amount of hydrochloric acid and resorcinol were added to the three kinds of sugar, glucose was light red, fructose was red, and sucrose did not change color, so that sucrose could be identified.

Then add a few drops of water to glucose and fructose respectively, because the grape cloud sugar has the reducing property and the bromine water fades, fructose has no reducing property, can not make the bromine water fade, so that the purpose of distinguishing these two sugars can be achieved.

Glucose and maltose are reductive because they both have an aldehyde group aldehyde group that is reducible.

Fructose is a ketose and is generally not reducible.

Glucose and sucrose are dehydrated and condensed without aldehyde groups, so they are not reducible.

Sucrose is a non-reducing sugar hydrolyzed fructose and glucose are both reducing sugars.

They are mainly structural differences: Reducing sugars contain aldehyde groups that are reducible.

Whether it is a reducing sugar or not depends on whether there are free aldehyde groups in its molecular structure. The reducing sugars that need to be mastered in the high school biology exam are glucose, fructose, and maltose. Sucrose is a non-reducing sugar.

Fructose is a reducing sugar because the carbonyl group rearranges when it meets a base and becomes an aldehyde group.

Sugars that can be oxidized to act as reducing agents are reducing sugars, and sucrose is not a reducing sugar.

It is not a reducing sugar.

Refers to glucose, fructose, galactose, lactose and maltose, etc.

Reducing sugars are glucose, maltose, and fructose, both of which are not polysaccharides.

Sucrose is a disaccharide whose molecular structure consists of a glucose molecule and a fructose molecule. Therefore, sucrose itself is not a reducing sugar.

Reducing sugar is a kind of sugar that can react with certain chemical reagents (such as Feilin reagent, Toren reagent, etc.) under specific conditions to produce colored products. These reactions typically involve the oxidation of aldehyde groups (or ketone groups, depending on the type of sugar) in the sugar molecule to carboxyl groups while generating reducing sugar alcohols or uronic acids.

The glucose moiety in the sucrose molecule carries an aldehyde group, while the fructose moiety carries a ketone group. Although both of these groups can be oxidized under specific conditions, since sucrose is made up of two sugar molecules, when they are combined, the aldehyde and ketone groups cancel each other out, making sucrose no longer reducible. Therefore, sucrose itself is not a reducing sugar.

Sucrose is not the raw sugar of the trouser ruler.

Sucrose, the main component of table sugar, is a kind of disaccharide, which is formed by the condensation and dehydration of the hemiacetal hydroxyl group of a molecule of glucose and the hemiacetal hydroxyl group of a Huyun polymer fructose. Sucrose has a sweet taste, no odor, is soluble in water and glycerol, and slightly soluble in alcohol. It has the ability to quietly rotate the photo, but there is no variable optical rotation.

Sucrose is almost universally found in leaves, flowers, stems, seeds, and fruits in the plant kingdom.

It is especially abundant in sugar cane, sugar beet and maple sap. Sucrose has a sweet taste and is an important food and sweet condiment. It is divided into white sugar, red sugar, white sugar, rock sugar, and brown sugar.

Sucrose is not reducing sugar.

The hydrolysates of sucrose are fructose and glucose.

Glucose is a reducing sugar.