47 votes
Accepted

Why are sugars in whole fruits not digested the same way sugars in juice are?

Sugars in 100% natural fruit juices are chemically the same as in whole fruits. They mainly include glucose, fructose and sucrose: Apple nutrition data (expand the carbohydrate section) Apple juice ...
Jan's user avatar
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22 votes
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What is the difference between added sugars and natural sugars in processed foods?

One of the ways to measure the impacts of sugar in different foods is with the glycemic index, which is a measure of how quickly blood sugar rises after eating. Faster rises in blood sugar are thought ...
Bryan Krause's user avatar
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14 votes
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Why is ATP produced in photosynthesis used to synthesize glucose?

As far as I can understand your question, you wish to know why a plant cell consumes ATP to produce glucose when it can directly use the ATP as an energy molecule. ATP is an energy currency and is ...
WYSIWYG's user avatar
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10 votes
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(Why) can't blood sugar spikes be countered by consuming fiber generally?

Yes, adding fiber to diet can reduce the "spikes" in blood sugar. Just a couple references I found quickly, I have not reviewed them closely so I'm not sure of their quality and there may be ...
Bryan Krause's user avatar
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9 votes
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Why doesn't sugar spoil?

Our food mostly gets spoiled by bacteria and / or fungi. There are 2 main reasons for sugar crystals not getting spoiled. 1- Lack of sufficient amount of water to sustain metabolic processes by ...
JM97's user avatar
  • 4,796
8 votes

Is plasma membrane permeable to sucrose

No, but yes. Sucrose is a large polar solute. Because it is polar, it cannot easily pass the hydrophobic core of the membrane. So, if the lipids of the plasma membrane are mostly impermeable to ...
James's user avatar
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7 votes

Why are sugars in whole fruits not digested the same way sugars in juice are?

Drinking the juice without the fruit can easily lead to over-consumption. It is after all harder to eat four apples than drinking 500ml apple juice. As the liver breaks the fructose through ...
Pebermynte Lars's user avatar
7 votes
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Why is sugar absorbed very fast into the blood stream?

In short, sugars are absorbed quicker than proteins and fats because they pass through the stomach quicker and their digestion is simpler. Sugar can be absorbed through the mouth mucosa when applied ...
Jan's user avatar
  • 8,079
6 votes

Can fructose take multiple forms ? Which of these structures of fructose is correct?

The two structures on the left are correct; the one on the upper left is the alpha-D-fructofuranose form, while the one on the lower left is the beta-D-fructofuranose form. Fructose is a ketohexose (a ...
Vikki's user avatar
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5 votes

Is sugar absorbed into the bloodstream through the walls of the mouth?

Simple sugars such as glucose, fructose and galactose will be absorbed. They are most probably transported by a common carrier, which is why if you present both glucose and galactose, the presence of ...
S Pr's user avatar
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5 votes

What is the difference between added sugars and natural sugars in processed foods?

The label is so you know how much sugar has been added, and juice just has issues with the label in the US. It is put on the label so you can see how much sugar the companies are adding, compared to ...
John's user avatar
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4 votes

Is sugar absorbed into the bloodstream through the walls of the mouth?

The absorption of sugar from the mouth is possible and it was successfully tested for treatment of hypoglycemia. In all mentioned studies, they used D-glucose (dextrose), which is a common natural or ...
Jan's user avatar
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4 votes

(Why) can't blood sugar spikes be countered by consuming fiber generally?

Prof. Dr. Robert Lustig says that both soluble and insoluble fibers are needed to avoid sugar spikes. Excerpts: The fiber in real food is of two kinds: soluble, which is globular (e.g. beta-glucan, ...
David Jonsson's user avatar
4 votes

Biochemistry - Plastic eating microbes at home

Although you should be able to find bacteria that can grow on plastic, I think your criteria of 'not difficult to find' might be a challenging one to meet. Poly(ethylene terephthalate) (PET) is a ...
Noah Sprent's user avatar
4 votes

Do Mannose and Galactose yield the same products as Glucose when oxidized?

The answer to this question is yes. And it is obvious to anyone familiar with metabolism. I hesitated to give a formal answer, but I hate answers in comments, so let me supplement this with some ‘...
David's user avatar
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4 votes

Why are sugars in whole fruits not digested the same way sugars in juice are?

Jan's answer is great, but I'm just going to quote the paper you reference: The systematic review of the effect of intake of free sugars on body weight included 30 of the 7895 RCTs and 38 of the ...
Luaan's user avatar
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3 votes

Can plants break down cellulose for energy?

Plants do not produce extra cellulase to break down cellulose for an energy boost when they are grown in dark conditions (that I know of). But remember, cell walls are the structures maintaining ...
laporp's user avatar
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3 votes

Why and how does falsifying sensory information work?

These are learning phenomena you describe. I'll try to explain a simple way to think about this. By default, sweet foods are appetitive and, for instance, strongly bitter foods are aversive. However, ...
S Pr's user avatar
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3 votes
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Does the sun light have to have *direct access* to fruits to make them sweet?

It would depend if the fruit has the ability to sense or capture light. This depends on chlorophyll mostly, found in cellular organelles called chloroplasts. If the fruit is incapable of capturing ...
S Pr's user avatar
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3 votes

Sugars which are Carbohydrates and vice-versa?

You need to make a distinction between polymers and monomers (or dimers). Typically, sugars are monomers like glucose, maltose, or fructose. Sucrose (table sugar) is a dimer. These are all ...
mdperry's user avatar
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3 votes
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What would kill you first water or cola?

The LD 50 listed on the wikipedia page you link to is 90 mL/kg, which would be about 6 liters for a 68 kg (150 lb) person. This is consistent with at least one report, where someone died from drinking ...
Sean Johnson's user avatar
3 votes

What is the difference between added sugars and natural sugars in processed foods?

Natural sugars are mostly glucose, fructose, and saccarose. Added sugars can be anything, from glucose to a variety of syrups. There isn't much difference, although caramelized sugars (brown syrups) ...
alec_djinn's user avatar
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2 votes

Does the body prioritise the use of available sugar before fat?

In a very simplified explanation - the body usually picks the process which is easiest/ fastest which would be to absorb the glucose then the fat would be used for energy as this takes longer to ...
CatCochrane's user avatar
2 votes

Carbohydrate in egg white

The one I found is Ovomucin,though it's not a pure carbohydrate. Ovomucin is a highly glycosylated protein and approximately 33% of ovomucin is made up of carbohydrates. Nutritional Values of Egg ...
Tyto alba's user avatar
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2 votes

Sugars which are Carbohydrates and vice-versa?

Although one might naïvely imagine that the term carbohydrate is used for a molecule containing carbon, hydrogen and oxygen, this is not the case as, if so, it would include compounds like fatty acids....
David's user avatar
  • 25.7k
2 votes

Sugars which are Carbohydrates and vice-versa?

The statement in your question is correct. All sugars are carbohydrates but not all carbohydrates are sugars. In fact, sugars are by definition carbohydrates. Wikipedia defines sugars as : Sugar ...
March Ho's user avatar
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2 votes
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Why is neutralizing important when carrying out the Benedict test?

Benedict's reagent is used mainly to test the presence of reducing sugars. However, it can also be used to test non-reducing sugars indirectly. For that to happen, non-reducing sugars are first ...
biologist_Jaishree's user avatar
2 votes

What is the difference between added sugars and natural sugars in processed foods?

If you live in the E.U., a beverage labeled "juice" may not contain added sugar. If both beverages you compare are 100% juice from the same fruit, adding sugar to one would lead to it having ...
Peter - Reinstate Monica's user avatar
1 vote

What advantage does lactose have as the main sugar in milk?

One of the advantages of lactose in breast milk is that it is digested slower than sucrose and its ingestion results in lower fluctuations of blood glucose levels thus being a stable source of energy. ...
Jan's user avatar
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