Nutrients
Carbohydrates in food
Carbohydrates in food [replacing lesson: Carbohydrates in food]
Simple sugars
Compound sugars
Proteins in food
Amino acids build proteins
Biochemistry: Enzymes
Fats in food
Vitamins
Minerals
Compound sugars
Which of these is a disaccharide?
Wow, four sugar lumps in your coffee. Mmmmm, yummi. Juice is much healthier! I bet there's more sugar in that glass than in my coffee. Let's find out if Jenny's right - and if it's the same kind of sugar.
We usually divide sugars into two groups. simple sugars and disaccharides. Let's start with the simple ones. Here we find glucose - of which there is a lot in fruit and berries. Another simple sugar is fructose, which is also found in fruits and berries.
A third simple sugar - galactose - is found in milk. In nature, simple sugars often connect, two by two. They then form a double sugar - a disaccharide. Di means two, and saccharide is another word for sugar. When fructose and glucose merge, they form a sugar called sucrose.
Though usually we call sucrose just - sugar - or table sugar. That's the sugar Jenny pours into her coffee. And it's made from sugar cane or sugar beets. Another disaccharide is maltose - composed of - two glucose molecules. Maltose is formed when grains ferment or germinate.
Maltose is found for example, in beer and soy sauce, but only in tiny amounts. A third disaccharide is lactose - also known as milk sugar. It consists of galactose and glucose. As the name indicates, lactose is found in milk. Common to all sugars is that they taste sweet and contain a lot of energy.
Let's see how much energy orange juice contains. This glass holds two-and-a-half deciliters. That's equivalent to the juice from four oranges. Half of the sugar in the juice is sucrose. The rest is glucose and fructose.
Totally it will be - about twenty-five grams of sugar. Or eight sugar lumps. That's equal to the energy you consume skipping rope for ten minutes. But if you're sitting still - the body consumes only this small amount. When you eat sugar, the simple sugars travel quickly into the bloodstream... ...
while disaccharides must first be divided into simple sugars by enzymes. The enzyme that splits lactose is called - lactase. Almost all children have lactase in their stomachs. But for many adults, the stomach no longer produces lactase. Without lactase the lactose passes through to the large intestine where it's broken down by bacteria.
If then you drink a lot of milk, it can result in pain and an upset and gassy stomach. This inability to digest lactose is called - lactose intolerance. In many parts of the world it's quite normal for adults to be lactose intolerant. In other parts, most people can digest lactose without a problem. Here's a summary.
We distinguish between simple sugars and disaccharides. The most common disaccharide is sucrose, which we normally just refer to as 'sugar'. Sugars contains a lot of energy. A glass of soda or juice contains as much energy as you use for a tough ten-minutes of rope jumping. Or two hours rest. - Oh. - Hey Jenny, give me that skipping rope!